SHIP HANDLING AND MANOEUVERING BASICS.pptx

SHIP HANDLING AND MANOEUVERING

1. S h i p M a n e u v e r i n g T e c h n i ca l R e f e r e n c e P a n a m a C a n al G a t u n L o c k

2. SH I P TE RM I N O L O GY Sh i p h a n d li n g

3. SH I P TE RM I N O L O GY B o w S t e m F o r ec a s tl e H a w se pip e W e a t h e r d e c k s D ra f t F r e e bo a r d Su p e r s t r u c t u re P ilo t h o u se M a st Y a r d a r m T r u ck S t a ck K e e l Sh a ft P r o p e l l e r R u d d e r S t e r n T r a n s o m W a t e r li n e Sh i p h a n d li n g

4. L e ss on C o n t e n ts Sh ip h a n d li n g T h e o ry L a w s o f M o t io n Co nt r o l labl e F o rc e s U n c o n t r ollabl e F o rc e s Sh ip h a n d li n g T e r m i n olo g y G ro u n d T a c k l e G ett i ng U n de r w a y Si n gl e Sc r e w C h a r a c t e r i st i cs Tw in S c r e w C h ar a c t e ri s t ic s T ug H a n dl i ng M a n O v e r b o a r d R e c o v e r y

5. S hi p han d lin g Th e o r y : M o t i on Va r i ou s f o r ce s a c ti ng on t h e s h i p c r e ate mo v e m e n t. N e wt o n’ s L a w s o f Mo ti on Un l e s s a c t e d u p o n b y a n o u t sid e f o r c e : An o b j e ct in m o t i o n t en d s t o st ay in m o t io n. An o b j e ct at r es t ten d s t o st ay at r es t . T h e r e s u l t i n g mo t i o n o f an o b j e c t i s t h e su m o f a l l f o r ce s a c t i n g on i t . E v e ry act ion h a s a n e q u a l a n d o p p o si te r e act io n .

6. W h a t i s V e ss e l H a n d l i n g ? V e ss e l h a n d li n g i s b a s e d o n t h e b a s i c k n o w l e d g e t h a t a v e s s e l f l o a t s i n t h e w a t e r a n d r e tu r n s t o i t s or i g i n a l p o s iti o n a f t er a li s t . I t i s ma n e u v e re d w i t h t h e as s i s t a n c e of t h e r u d d e r , ma i n e n g i n e ( s ) a n d o t h er a u x i l i a ry e q u i p m e nt , u s i n g k n o w l e d g e of t h e r o lli n g , p i t c h i n g a n d y a w i n g c h a r a c t er i s ti c s of t h e v e s s e l i n w a v e s . In h a nd li n g t h e v e ss e l i t i s n e c e s s ary t o c o n s i d er th e e f f e c t s of e n v i r o n m e n t a l c o n d i t i o n s w h il e c o nt r o lli n g t h e p o s i t i o n of t h e v e s s e l , i t s a t ti tu d e, a n d i t s s p ee d , t o m o ve t h e v e s s e l i n t h e d e s i g n e d d i r e c t i o n i n a s a f e a n d e ff i c i e n t m a n n e r , a n d t o s t o p a t t h e i n t e n d e d p o s i t i o n . ( T h eory a n d P r a c t i c e of S h i p H a n d li n g , Ki n z o I n o u e , H o n o r a r y P r o f e s s o r , K o b e U n i v e r s i t y) . ̎

7. Ship Handling and Maneuvering Shi p H a n dlin g a n d M an e u v eri ng i s d e f i ne d as t h e ar t of pr o p e r c o n t rol o f a s hi p w hil e u nd e r w a y , e s p e c iall y in ha r b o r s , a r o u n d d o c k s a n d pi e r s . I t i s on e o f t h e sk il l s t ha t an y s hi p h a nd l e r f i nd s v er y s a t i sf y in g w he n w ell a cc o m pli s h e d . T h e m o s t b a s i c t h i n g t o b e u n d e r st o o d in s hi p h a n dlin g is t o k n o w an d a n t i c ip a te h o w a s hi p b e h a v e s u n d e r a ll c i r c u m s t a n c e s a n d w ha t o r de r s s h oul d b e gi v e n in o r de r to m a k e t h e s hi p b e ha v e an d m o v e e x a ct l y t h e w a y y o u w ant he r t o . T h e d i f f e r en ce be t w ee n t h e sh i ps’ h e a din g a n d t h e a c t u a l di r e c t i o n o f mo v emen t o f t h e s hi p s hou l d a l so be c o n s t a n t l y a t t e nd e d t o a s t h i s i s e ss e n t iall y imp o r t a n t at s lo w s peed s an d w he n t her e ar e w in d an d c urren t .

8. V e s s e l w i t h S t a b i li t y M e a n s R u d d e r , m a i n e n g i ne, t hr u s t e r s , a n c h o r s, mo o r i n g l i n e s, t u g s e t c . V e ss el ma n e u v e r a bil i t y R olli n g , P i t c h i n g a n d Y a w i n g c h a r a c t e ri s t i c s in w a v e s E n v i r o n m e n t al c o nd i t io n s G eo g r a p h y ( e x i s t e n c e of s h allow a r eas a n d w a t er d e pt h e t c . ) F a c ili t i e s ( p ort f a c ili t i e s ) N a v i ga t ion ( bu o y s , f i s h i n g b o a t s , m ari n e t r a f f ic e t c . ) So c ial ( r e g u l a t io n s , n a v i ga t ion r e g u l a t io n s e t c . ) N a tu r e ( w i nd , t i d al f l o w s , v i s i b ili t y , w a v es e t c. ) S hi p N a v i g a t o r C o n t r o l of v e ss el p o s it io n , a t t i t ud e , a n d s p e e d f or s a f e a n d e f f i c i e n t m o v e m e n t i n th e r e qui r ed di r e c ti o n s t o p p i n g a t t h e r e q ui r ed p o s it i o n O p e r a t e v e s s e l a s d e sc r i b e d ̏

9. S hi p han d lin g T h e o r y : F o r c es C on t r o ll a b l e P r op e l l e r R u d d e r B o w T h r u s t e r / A P U Moo r i n g L i n e s A n ch o rs T u g s Un c on tr o ll a b l e W i n d Cu r r e n t / T id e s Se as W a t e r D e p t h

10. Co n tr o ll ab l e F o r c e s

11. P r o p e ll e rs P r o v i d e s t he mo s t i mpo r t an t s o u r c e o f f o r c e on a s h i p. (U s ua ll y ) mak e s s h i p g o f o r w a r d. Most s h i p s ha v e 2 p r o p e ll e r s . A i r c r aft c a rri e r s / P at r ol C r aft ha v e 4. F r i g a t e s ha v e 1. C o n t r oll a bl e F o r c e s

12. P r o p e ll e rs F o r c e s r e s u lti ng f r om t h e u se o f t he p r op e l l e r s : F o r wa r d ( o r r e v e r s e ) t h r u st S id e F or ce C o n t r oll a bl e F o r c e s

13. P r o p e l l er T h r u s t A r e s u l t o f t h e p r op e ll e r s p i n n i ng on i ts s h a f t. C au s e d b y a p r e ss u r e d i f f e r e n tial b e t wee n t h e o p po s i t e s i d e s o f t h e p r op e l l e r b l ad e . C o n t r oll a bl e F o r c e s

14. P r o p e l l er T h r u s t R o t a t i o n o f p ro p e ll e r b lad e W a t e r Fl o w Lo w P r e s s u r e P ro p e l l e r B lad e H igh P r es s u r e R e s ul t ing T h r u s t C o n t r oll a bl e F o r c e s

15. C o n t r o ll in g P r o p e l l er T h r u s t D e p e nd s on t y p e o f p r o p e l l e r s Fixe d P i t c h P r o p e l l e r s C o n t r o l la b l e P i t c h P r op e ll e rs C o n t r oll a bl e F o r c e s

16. C o n t r o ll a b l e P i t c h Pr o p e ll e r s F o u nd on a l l g a s t u r b i n e s h i p s and s o m e d i e s e l am p h i b s • - 12 kts sh a f t r o t a t e s a t 55 R P M t h r u s t ( s p e e d) c o n t r o l l e d b y ch a n g i n g t h e pi t c h o f t h e pr o p e l l e r bl a d e C o n t r oll a bl e F o r c e s

17. C o n t r o ll a b l e P i t c h Pr o p e ll e r s >12 kts t h r u s t c o n tr ol l e d b y c h a n gi n g t h e s p e e d (R P M) o f t h e sh af t . The s h aft a l w a y s sp i n s i n s a m e d i r ec ti on w h e t h e r g o i ng f o r w a r d o r b a ck w a r d. C o n t r oll a bl e F o r c e s

18. F i x e d P itc h P r o p e ll e rs F o u nd on s t e am s h i p s ( c a rr i e r s , s u bs, amph i b s ) C ann o t c han g e p i t c h o f p r o p e l l e r Th r u st ( s p ee d ) c o n tr o l l e d b y c han g i ng s p e e d o f t he s h aft To go b a c k w a r d s , m u st s t o p s h aft and s p i n t h e s h aft i n t he o pp o s i t e d i r ec tion. C o n t r oll a bl e F o r c e s

19. S i d e F o r ce C au s e s s t e r n t o mo v e s i d ew a y s i n t he d i r ec ti on o f p r op e l l e r r o t a ti o n . P ro p e l l e r C o n t r oll a bl e F o r c e s

20. S i d e F o r c e A s t e rn A h ea d T wi n S c r e w S i d e F o r c e B o tt o m S i ng l e S c r ew G oi n g A hea d S i d e F o r c e S i d e F o r c e C o n t r oll a bl e F o r c e s

21. Sc r ew C u r r e n t C on s i s t s o f t w o p a rts Su c t i o n C u rr e n t - g o i n g i n t o t h e p r o p e l l e r Di sch a r g e Cu r r e n t ( P r o p W a sh) - c o m e s o u t o f t h e p r o p e l l e r S u c t i o n C u r r e n t D i s c h a r g e C u r r en t A c t s o n Ru d d e r P ro p e l l e r C o n t r oll a bl e F o r c e s

22. Ru d d e r s Us e d t o c on tr ol s h i p ’ s h e ad i ng b y mo v i ng t he s t e r n. To h a v e an e f f e c t , mu st h a v e a f l o w o f w at e r a c r o ss t he r ud d e r . N o r m all y t h i s f l o w o f w ater i s t he d i s c h a r g e c u rr e n t o f t he s c r e w . C o n t r oll a bl e F o r c e s

23. Rud d e r F o rc e H L i o g w h P r e s s s s u r e A r e a H L i o g w h P r e s s s s u u r e A r e a A c t s a w i ng R u d d er W a t e r Fl o w Rud de r F o rc e C o n t r oll a bl e F o r c e s

24. Pr o p e l l e r s / R u dd e rs P r i m a r y m e an s o f c on tr o ll i n g t h e s t e r n T h r u st S i d e F o r ce Rud de r F o r c e C o n t r oll a bl e F o r c e s

25. P i v o t p oin t concept

26. P iv ot P o in t I mag i n a r y po i n t on t he s h i p ’ s ce n t e rl i n e abou t w h i c h t he s h i p p i v o ts P i v o t P oin t T h r u st Si d e F o r ce Rud d e r F or ce C o n t r oll a bl e F o r c e s

27. T h e s h i p ’ s p i v o t p o i n t The turning ef f ect of a v essel will ta k e ef f ect ab o ut the shi p ’s ‘p i v ot poin t ’ and th i s posit i on, with the a v e r age design v essel, lies at about the sh i p ’s Cent r e of G ra vit y , w hi c h is gene r al l y nea r l y amidsh i p s (assum ing th e v essel is on e v en k eel in calm w a t er con d itions). A s the ship m o v es f or w a r d unde r engine po w e r , th e p i v ot p o int wil l b e caused t o m o v e f or w a r d with th e m o ment u m on th e v essel. I f th e w a t er d oes not e x ert r esistan c e on th e hull th e p i v ot p o int w ould assum e a p o sition in the bo w r egion. H o w e v e r , p r ac t ica l l y th e p i v ot p o int m o v es t o a p o sition a p p r o xima t e l y .25 of th e ships length (L ) f r om the f or w a r d positio n . Sim ila r l y , if th e v essel is m o v ed as t ern, th e s t ern m otion w ould cause th e P i v ot P oint t o m o v e af t and adop t a ne w posit i on app r o xim a t e l y 0.25 of the shi p ’s length f r om the ri g ht af t posi t ion. I f th e turning mot i on of t h e v essel is conside r ed, with us e of th e rudd e r , w hile th e v essel is m o v ed ahe a d b y engines, it can b e seen tha t t he p i v ot poin t w ill f oll o w th e a r c of th e turn.

28. I f th e turnin g motion of th e v essel is conside r ed, with us e of th e rud d e r , w hile th e v essel is m o v ed ah e ad b y engines, it can b e seen th at th e p i v ot p o int will f oll o w the a r c of the tur n .

29. The c o mb i ned f o r ces of w a t er r esistan ce, f or w a r d of the p i v ot p o int and the op posing t urning f o r ces f r om the rud d e r , aft of the p i v ot poin t , cause a ‘couple ef f ec t ’ t o ta k e pla ce. The r esult a nt turning mot i on on the v essel sees the p i v ot p o int f oll o win g th e a r c of the turn.

30. P i v ot poin t mea n s th e cen t er o f a n y r ota t i onal s y s t em. I t is v ery vi t a l t o kn o w th e lo c a t ion o f th e p iv ot p o int a s th e ship h andli n g depends g r ea t l y on kn o wi n g th e lo c a tion of th e same. The p i v ot poin t is n ot a f i x ed poin t . I t c h a n g e s th e loca t ion dependi n g on th e bel o w f ac t ors ; - W h en t he v essel is a t r est or static, th e p iv ot p o int is alm o st th e same a s tha t of th e cen t er of G ra vi t y , w hich is de n o t ed b y G. W h en th e v ess e l m o v es f or w a r d, th e posi t ion of p i v ot poin t shif t s f or w a r d. The n ew p i v ot p o int wil l b e ab o u t 1 / 4 t h of th e Length of th e v essel f r om th e f or w a r d.

31. W h en t he v essel m o v es as t er n , th e po s ition of th e p iv ot p o int shifts t o w a r ds th e s t er n . The n e w p iv ot poin t wil l b e abo u t 1/4 t h of t he Leng t h of th e v ess e l f r om th e s t er n . w hile t he v ess e l m o v es as ter n , th e p i v ot poin t m o v es t o w a r ds th e s t er n . This shi f t o f the p iv ot p o int can b e mad e t o a dv an t ag e . Let's ass u m e tha t b oth t he tug s a r e p u llin g wi t h t h e same f o r ce. Si n ce th e p i v ot poin t has shif t ed m o r e t o w a r ds th e s t er n , th e ef f ect of t he F or w a r d tu g w i l l b e in c r e a sed au t o m a t ical l y . The r e a son bei n g tha t th e t urn in g l e v er f or th e F or w a r d tu g has bee n in c r e a sed, becaus e of th e shi f t o f th e p i v ot poin t . The r e f o r e the act i on of th e f or w a r d tu g wil l b e do m in an t o v er th e s t ern tug . The r e f o r e th e b o w wil l m o v e t o PO R T .

32. T h e p i v o t p o i n t a t a nc h o r I t sho u l d b e no t ed th a t w hen th e v essel goe s t o a ncho r t h e p i v ot poin t m ov es r i g ht f or w a r d an d e f f ect i v e l y h olds t h e b o w in one po s ition. A n y f o r ces a cting on t h e h u ll , such a s f r om win d or cur r ents, w ould cause t he v essel t o m o v e abo u t t h e h a w se pip e position. Use of t h e r u dder can ho we v e r , b e empl oy ed w hen a t ancho r , t o p r o vide a ‘shee r ’ t o t h e v essel, w hich could b e a usefu l actio n t o an g l e t h e l e ngt h of th e v essel a w a y f r om loca l i z ed dange r s.

33. P i v o t P o i nt S h i p t wi st i n g w i t h n o w a y o n. C o n t r oll a bl e F o r c e s

34. P iv ot P o in t Us u a l l y l o c ate d 1 / 3 t he l e n g t h o f t he s h i p f r om t he b o w . ( J u st b e h i nd t he b r i d g e .) Piv o t po i n t i s no t f i xe d C o n t r oll a bl e F o r c e s

35. F o r c es w hi c h a f f e c t l o c a t i on o f t h e P iv ot P o i n t H e a d w ay o r S t e r n w ay S h i p’ s S p e e d An c ho r s Moo r i ng Li n e s Tu g s C o n t r oll a bl e F o r c e s

36. W in d A c t s on t he s a i l a r e a o f t he s h i p E x po s e d sup e r s t r u c t u re H u ll s t r u c t u re S h i p s t e n d t o b a c k i n t o t he w i nd 30 k t s o f wi n d = 1 k t s o f c u rr e n t C u r re n t A c t s on t h e un d e rw at e r p a r t o f t he s h i p. C r e ates s e t and d r i f t. U n c o n t r o l l a bl e F or ce s

37. D e p t h o f W a t e r S qu at - O c c u r s a h i gh s p ee d s bo w o f a sh ip r id e s u p o n t o t h e bo w w a v e s t e r n o f a sh ip t e n d s t o si n k S h a l l o w w ater e ff ec t s . U n c o n tr ol l ab l e F or c e s

38. SH I P TE RM I N O L O GY B o w S t e m F o r ec a s tl e H a w se pip e W e a t h e r d e c k s D ra f t F r e e bo a r d Su p e r s t r u c t u re P ilo t h o u se M a st Y a r d a r m T r u ck S t a ck K e e l Sh a ft P r o p e l l e r R u d d e r S t e r n T r a n s o m W a t e r li n e Sh i p h a n d li n g

39. H e a d w ay m o vi n g f or w a r d t h r u t h e w a t e r S t e r n w ay m o vi n g b ack w ar d s t h r u t h e wa t e r B a r e S t eer a g ew ay t h e m i n i m um s p e e d a sh ip c a n pr o c e e d a n d s t i l l ma i n t a in c o u r s e u si n g t h e r u d d e rs Sh i p h a n d li n g: T e r m s

40. S t a nd b y l i n e s Ta k e i n t he s l a c k Ta k e a s tr a i n H e a v e a r o u nd A v ast h e a v i ng H o l d C h e c k D o ub l e up S i ng l e up Ta k e i n S l a c k E a s e Ta k e t o t h e c ap s t a i n Gr o u n d Ta c kl e , M o o r i n g L i n e s Se q u e n c e : Command s : Sh i p h a n d li n g:

41. S a f e ty B att l e d re ss S n a p b a c k z on e Tu g s Pi l o t s l a d d e r Sh i p h a n d li n g: Gr o u n d Ta c kl e , M o o r i n g L i n e s

42. L e ss on C o n t e n ts Sh ip h a n d li n g T h e o ry L a w s o f M o t io n Co nt r o l labl e F o rc e s U n c o n t r ollabl e F o rc e s Sh ip h a n d li n g T e r m i n olo g y G ro u n d T a c k l e G ett i ng U n de r w a y Si n gl e Sc r e w C h a r a c t e r i st i cs Tw in S c r e w C h ar a c t e ri s t ic s T ug H a n dl i ng M a n O v e r b o a r d R e c o v e r y

43. S hi p han d lin g Th e o r y : M o t i on Va r i ou s f o r ce s a c ti ng on t h e s h i p c r e ate mo v e m e n t. N e wt o n’ s L a w s o f Mo ti on Un l e s s a c t e d u p o n b y a n o u t sid e f o r c e : An o b j e ct in m o t i o n t en d s t o st ay in m o t io n. An o b j e ct at r es t ten d s t o st ay at r es t . T h e r e s u l t i n g mo t i o n o f an o b j e c t i s t h e su m o f a l l f o r ce s a c t i n g on i t . E v e ry act ion h a s a n e q u a l a n d o p p o si te r e act io n .

44. S hi p han d lin g T h e o r y : F o r c es C on t r o ll a b l e P r op e l l e r R u d d e r B o w T h r u s t e r / A P U Moo r i n g L i n e s A n ch o rs T u g s Un c on tr o ll a b l e W i n d Cu r r e n t / T id e s Se as W a t e r D e p t h

45. Co n tr o ll ab l e F o r c e s

46. P r o p e ll e rs P r o v i d e s t he mo s t i mpo r t an t s o u r c e o f f o r c e on a s h i p. (U s ua ll y ) mak e s s h i p g o f o r w a r d. Most s h i p s ha v e 2 p r o p e ll e r s . A i r c r aft c a rri e r s / P at r ol C r aft ha v e 4. F r i g a t e s ha v e 1. C o n t r oll a bl e F o r c e s

47. P r o p e ll e rs F o r c e s r e s u lti ng f r om t h e u se o f t he p r op e l l e r s : F o r wa r d ( o r r e v e r s e ) t h r u st S id e F or ce C o n t r oll a bl e F o r c e s

48. P r o p e l l er T h r u s t A r e s u l t o f t h e p r op e ll e r s p i n n i ng on i ts s h a f t. C au s e d b y a p r e ss u r e d i f f e r e n tial b e t wee n t h e o p po s i t e s i d e s o f t h e p r op e l l e r b l ad e . C o n t r oll a bl e F o r c e s

49. P r o p e l l er T h r u s t R o t a t i o n o f p ro p e ll e r b lad e W a t e r Fl o w Lo w P r e s s u r e P ro p e l l e r B lad e H igh P r es s u r e R e s ul t ing T h r u s t C o n t r oll a bl e F o r c e s

50. C o n t r o ll in g P r o p e l l er T h r u s t D e p e nd s on t y p e o f p r o p e l l e r s Fixe d P i t c h P r o p e l l e r s C o n t r o l la b l e P i t c h P r op e ll e rs C o n t r oll a bl e F o r c e s

51. C o n t r o ll a b l e P i t c h Pr o p e ll e r s F o u nd on a l l g a s t u r b i n e s h i p s and s o m e d i e s e l am p h i b s • - 12 kts sh a f t r o t a t e s a t 55 R P M t h r u s t ( s p e e d) c o n t r o l l e d b y ch a n g i n g t h e pi t c h o f t h e pr o p e l l e r bl a d e C o n t r oll a bl e F o r c e s

52. C o n t r o ll a b l e P i t c h Pr o p e ll e r s >12 kts t h r u s t c o n tr ol l e d b y c h a n gi n g t h e s p e e d (R P M) o f t h e sh af t . The s h aft a l w a y s sp i n s i n s a m e d i r ec ti on w h e t h e r g o i ng f o r w a r d o r b a ck w a r d. C o n t r oll a bl e F o r c e s

53. F i x e d P itc h P r o p e ll e rs F o u nd on s t e am s h i p s ( c a rr i e r s , s u bs, amph i b s ) C ann o t c han g e p i t c h o f p r o p e l l e r Th r u st ( s p ee d ) c o n tr o l l e d b y c han g i ng s p e e d o f t he s h aft To go b a c k w a r d s , m u st s t o p s h aft and s p i n t h e s h aft i n t he o pp o s i t e d i r ec tion. C o n t r oll a bl e F o r c e s

54. S i d e F o r ce C au s e s s t e r n t o mo v e s i d ew a y s i n t he d i r ec ti on o f p r op e l l e r r o t a ti o n . P ro p e l l e r C o n t r oll a bl e F o r c e s

55. S i d e F o r c e A s t e rn A h ea d T wi n S c r e w S i d e F o r c e B o tt o m S i ng l e S c r ew G oi n g A hea d S i d e F o r c e S i d e F o r c e C o n t r oll a bl e F o r c e s

56. Sc r ew C u r r e n t C on s i s t s o f t w o p a rts Su c t i o n C u rr e n t - g o i n g i n t o t h e p r o p e l l e r Di sch a r g e Cu r r e n t ( P r o p W a sh) - c o m e s o u t o f t h e p r o p e l l e r S u c t i o n C u r r e n t D i s c h a r g e C u r r en t A c t s o n Ru d d e r P ro p e l l e r C o n t r oll a bl e F o r c e s

57. Ru d d e r s Us e d t o c on tr ol s h i p ’ s h e ad i ng b y mo v i ng t he s t e r n. To h a v e an e f f e c t , mu st h a v e a f l o w o f w at e r a c r o ss t he r ud d e r . N o r m all y t h i s f l o w o f w ater i s t he d i s c h a r g e c u rr e n t o f t he s c r e w . C o n t r oll a bl e F o r c e s

58. Rud d e r F o rc e H l iog wh P r e s s s s u r e A r e a HLiogwh Pressssuure Area A c t s a w i ng R u d d er W a t e r Fl o w Rud de r F o rc e C o n t r oll a bl e F o r c e s

59. Pr o p e l l e r s / R u dd e rs P r i m a r y m e an s o f c on tr o ll i n g t h e s t e r n T h r u st S i d e F o r ce Rud de r F o r c e C o n t r oll a bl e F o r c e s

60. P iv ot P o in t I mag i n a r y po i n t on t he s h i p ’ s ce n t e rl i n e abou t w h i c h t he s h i p p i v o ts P i v o t P oin t T h r u st Si d e F o r ce Rud d e r F or ce C o n t r oll a bl e F o r c e s

61. P i v o t P o i nt S h i p t wi st i n g w i t h n o w a y o n. C o n t r oll a bl e F o r c e s

62. P iv ot P o in t Us u a l l y l o c ate d 1 / 3 t he l e n g t h o f t he s h i p f r om t he b o w . ( J u st b e h i nd t he b r i d g e .) Piv o t po i n t i s no t f i xe d C o n t r oll a bl e F o r c e s

63. F o r c es w hi c h a f f e c t l o c a t i on o f t h e P iv ot P o i n t H e a d w ay o r S t e r n w ay S h i p’ s S p e e d An c ho r s Moo r i ng Li n e s Tu g s C o n t r oll a bl e F o r c e s

64. Internal and External Factors In t e r n al Fac tors/For c e s T h e se a r e t h e f a c t o rs o r f or c e s I N S I D E t h e s hi p t h a t a f f e c t s h o w t h e v e s s e l b eha v e s o r pe r f or m s dur in g m an e u v erin g , s o m e e x ampl e s a r e : E n gin e P o w er , S p e c i f i c a t i o n o f P r opel l e r an d R u d d e r , M o or i n g L i n e s an d Anc hor , T hru st er s an d Vess e l Speed . Ext e r n al Fac tors/For c e s T h e se a r e t h e f a ct o r s o r f o r c e s t h a t ha p p e n s O UT SI D E t h e s hi p t h a t af f e c t s t h e m an e u v eri n g o f t h e v e ss e l w hil e under w a y , approachi n g a por t o r bei ng do ck ed , s o m e e x a m ple s are : T id e , A s u d d e n c h a ng e in w in d v elo c i ty a n d d i r e c t io n ( g u s t ), S e t a n d dr i f t, T h e p r o x i m i ty o f o t h e r v e s s e l s , T h e dept h o f harbor s.

65. External F actors/forces T i de - A t lo w ti de , the w a ter w il l be too sh a l l o w for the sh i p to m ov e and she w il l h i t the b o t t o m o f the h a rb or. T h i s me a n s th a t shi p s n e e d to sche d u l e th e i r a rri va l a t o r depa rture fro m some p orts ar o u n d the h i g h tides a t th o se p orts. S h i ps' mo o ring l i ne s tig h te n a s the tide ris es, and sl a cken w hen the ti d e g oe s o u t. H ig h tides h e l p i n n a vigati o n. T h e y ra i s e the w at e r l eve l cl o se to the sh o re s. T h i s h e l p s t h e sh i p s to arr i ve at h a rbor m o re ea si l y .

66. A sudde n chang e i n w i nd v elo c i t y an d dire c tion ( gus t ) - The Wind F orc e w il l develo p a s ide w a y s f o r ce on t h e v essel, a w a y f rom the expos e d sid e . Ma k i n g He a d w a y wit h S te r n to W in d , the ve s s e l lose s “co ur se s tabilit y ” a n d i s di f f ic ul t t o s t e e r, this ef f e c t i s g r e at e r whe n th e re i s al so a following Sea or Swel l .

67. Set an d dr i f t - Ign o ring s e t and d r if t can ca u se a m a r ine r t o get of f t hei r d e si r e d co u rse, s o m etim e s b y hun d re d s o f mi l e s . A m a rin e r n ee d s t o b e abl e to s te e r t h e ship and c o mp ensate for the e f f e c t s of s e t an d d rift the i r v e s sel while upon u n der w a y . T h e a ctual cou r se a ve s sel trave l s i s r ef e rred t o as the cou r se o v e r the groun d .

68. The p r ox i mit y of other v e s s els

69. Th e d e pth o f h a rbor s - Sh al l o w wa t er a f fe c ts the m aneu v er a b il ity o f ships limited con s i d era b l y . The wate r de pth wi l l change the pr essu r e d i s t ri b ution ar o u n d the vessel an d lead t o a n i n cr e a se in hydrodynami c force s .

70. Int erna l Factors/ force s un d e r the c ontro l o f the S h i p ha n d l er En g i n e p o w e r cha l l engin g to keeping co n t r o l . - It c a n be sl o w d o w n w h ile Th i s i s b ec a use reduction i n p r o p elle r speed r e d uc e s w a t e r fl o w o v e r the r u d de r an d the rudd e r b ec o m e s l e ss effectiv e . The conventi ona l a p pr o a c h for h a lti n g is to pu t e n g i n e s aste r n. Th e s h i p w ill b e l e ss r e s po nsi v e to ste e ri n g w h e n a pr o pell e r i s r ot a ting aste rn b e ca u s e the w a t e r fl o w acr o ss the ru d d e r is d i sr upt e d . In a d d i t i o n , th e re i s the d i sruptive e ff e ct o f tra n sv e rse thr u st.

71. Speed - T h e tur n i n g ci r cle w il l no t i n cre a se b y any therefore consid era b l e mar g i n w it h a n increa se i n spee d , b e c a us e the ste e r in g effect i s i n cr ea s e d ov e r the s a me pe rio d . G en e ra ll y s pe ak i n g , h i g h e r sp e e d s mean mo r e fo rce o n the rudd e r but a l so more mom e nt u m . S o , t h e h e a d w i l l turn fast e r, bu t the s h i p w i l l trav e l fart he r a l o n g i t s pr e vious trac k . The h i g h e r momentum a l so m e a n s more he e l i n g .

72. Ef f ec t o f t h e t y pe o f pr o pe l ler - Pr o p e lle r af f e c t s ev e r y p has e of p e r fo r m a nc e - ha n dling , ridin g, c o m f o rt, e n gi n e s af e t y . s p eed , a cceler a t i on, li f e , fuel e c o n o m y and I n b o a t a re de t er m ining p r o pellers p e r fo r m a nce, s e c o n d i n i m po r ta n ce onl y t o t he p ow e r avail a bl e f r o m t h e engi ne its e l f . With o u t t h e pr o pelle r 's thru s t, nothin g happen s .

73. R udder m o v e m en t an d t y pe - The ru d d e r a c t s as a h ydro f oil . B y itself , i t i s a passive in s t r um e n t a n d relies on wat e r p a ssi n g ov e r i t t o giv e i t ‘li f t ’ . R u d de r s a re pla c e d at t h e st e rn of a s h i p f o r this r e aso n and to take ad v a n t a g e of t h e f orwa r d pivo t point , w h ic h e n ha n ces t h e effe c t .

74. Thrusters - The t h r u st e r t a k e s s u c tion f r o m one side and th r o ws i t out at t h e oth e r side of the vessel, th u s mo v in g t h e ship in the o p p o site directio n. T hi s can be op e ra t e d i n bot h the di r e c tions, i. e . , p o rt t o s ta rb o ard and s t a rb o a r d t o p o r t . T h e b o w thru s t er s a re pla c e d b elo w t h e w ate r lin e of the s h i p.

75. A n c h ors a nd m o o r i n g li ne s - T h e p urpo s e o f an a n c ho r i s to k ee p a s h ip s af e and s e c ur e at a d e s ired l o c at i o n or to he lp c ontro l the s h ip durin g bad w e ath e r . H o w e v er , to a cc omp l i s h the s e vit a l purpo s e s, j u st ha vi n g an a n c ho r is not enough. T h e an c ho r mu st be s o l id, dependable, a n d u s e d properl y at the rig h t time and p l a ce. O n the o t h e r hand, an ancho r m o or i n g fi x e s a v es s e l ' s p o si t i o n relat i ve to a po i n t on the bottom of a w a te r w a y w ithout c onne cti n g the v e ss e l to s h o re. As a v e rb, mo o ring ref e rs to the ac t o f a ttachi n g a v es s e l to a mo ori n g .

76. Tugb o ats - T u g b oa t s are s m a l l, cap a b le p owe rful bo ats l a r g e o f steering sh i p s b y p u l l in g o r p u shi n g th e m . The y are use d to assis t these shi p s i n places w h er e they ar e un a bl e to m aneu v e r themselv es, such a s n a rr o w w a ter channels an d port s .

77. W in d A c t s on t he s a i l a r e a o f t he s h i p E x po s e d sup e r s t r u c t u re H u ll s t r u c t u re S h i p s t e n d t o b a c k i n t o t he w i nd 30 k t s o f wi n d = 1 k t s o f c u rr e n t C u r re n t A c t s on t h e un d e rw at e r p a r t o f t he s h i p. C r e ates s e t and d r i f t. U n c o n t r o l l a bl e F or ce s

78. D e p t h o f W a t e r S qu at - O c c u r s a h i gh s p ee d s bo w o f a sh ip r id e s u p o n t o t h e bo w w a v e s t e r n o f a sh ip t e n d s t o si n k S h a l l o w w ater e ff ec t s . U n c o n tr ol l ab l e F or c e s

79. Thre e Type s of Basic S h ip Mo t ion Lon gitud ina l mot i o n ( forwar d o r aste r n ) . Later al mot i o n (s i dew ays ) . Rotati o na l o r turni n g mot i on .

80. SHIP FACTORS THA T A FFECT MANUEVERI N G H a n d l i ng c ha racter i stics w i l l v a r y from ship t y pe to s h i p t y pe an d from s h i p to sh i p. H a ndl i n g q u a l i ties a r e d e termined b y s h i p d e s i g n , w h i c h i n turn d e pen d s o n the sh i p ’s i n tende d fu n cti o n. T y p i cal l y , d e s i g n rati os, such a s a sh i p ’ s l e n gth to it s b e am , determin e it s w i l l i n g n es s to tur n . H o w e v er , d e si r a b l e h a n d l i n g q u alitie s ar e a ch i eve d o n l y w h e n th e r e i s a b a l a nc e b e t w e e n d i recti o n a l sta b i l it y an d d i recti o n a l i n sta b i l it y .

81. Other Variable f a ctors af f ec t ing ship handl i ng. Huma n f ac tor – A del a y in time bet w een your g iv e n ord e r and the e x e c ut i o n of the or d e r w i l l affe ct how y o u i nten d to mo v e your s h ip. This i s c au s e d b y human fa c tors be c au s e the i nd i v i du a ls y o u a re or d er i n g m a y h a ve d iffere nt r e s pon s es d e p e n di n g on the i r train i n g and abil i t y to p erf o rm the j ob , or th a t o rde r s h a ve to be re la y e d b y an o ffic e r to the he lm s man, w h ic h is a ba d pract i ce that s houl d be a v o i d ed s o that t h e c onn i n g off i c e r s hou l d be ab le to g ive h is order s d irect l y to the h elm s man .

82. Wind an d c urre n t a r e u sual ly ass o ci a ted as b oth be i ng forces no t under cont r ol of the s hip h andle r. Th e t wo forces hav e , ho w ev e r , a d i ffe r e nt effe c t on t he sh i p because o f t he d if fe r en c e i n natu r e o f the t w o . When t h e shi p i s a f fected b y wi n d alon e an d move s th r ough the w a ter, the hull me e ts u n der wa ter r es is t anc e. When, o n t h e other hand, the ship ’ s moti on or i g i nates f r o m curre nt , the r e i s p r a ct i cal l y n o r esi s tan c e o f t h e ab o v e- w a t e r a rea to air . As w a t e r i s eigh t hundred t i me s de n se r t h a n sea level a tm o sphere , c u rre n t mu s t, than b y n a tu r e , ha v e w i nd, es p ecia l l y on cons i de r ab l y s t ronge r e f fe c t loaded ship s.

83. OCE A N CURR E NT Oc e a n c u r r e n t s a re t h e c o n t i n uo u s , p r edic t abl e , di re ct i o n al m o v e m en t o f s e a w a t e r d ri v e n b y gra v i t y , w in d ( C or io lis Ef f e ct ), a nd dir e c t io n s : m o v e m en t s w a t e r d en s i t y . O c e a n w a t e r m o v e s i n t w o hor i z o n t all y an d v er t i c all y . H or i z on t al a r e r e f er r e d t o a s c ur re n t s, w hil e v ertical c hange s ar e c alle d up w elling s o r do w n w ellin g. Oc e a n c u r r e n ts a c t m u ch l i ke a c o n v e y o r be l t , t ra n s p o r t i n g w ar m w a t e r an d pr e c ip i t a t i o n f rom t h e e q u a t o r t o w ar d t h e pol e s an d c ol d w ate r from t h e pol e s ba c k t o t h e tro pi c s .

84. Curr e nt has a direc t e f f e ct o n the unde r- wat er p a r t o f the ship a nd a n i ndirec t ef- fect ex p re s se d in mom e n t um a ft e r the ship al t e r s cours e o r come s ou t o f a cu r- r ent, wh e n the s hip wi l l carry momen t um in the dir e c t ion o f the cur r en t that t h e ship was previously sub j e cte d t o .

85. Effe c t of W ind an d C urre nt Where a s th e e f f ec t o f wind o n th e s h ip h a s t o b e co nsi dere d wi t h respe c t to th e pi v ot p oint, curre n t a f f e ct s a freely mo v i ng sh i p a s a w h ole a n d cons e que n tly i t s e f fect is o n t he cente r o f g r avit y . H o w eve r, w h e n w e try to keep th e shi p sta t io n a r y r e la t ive t o th e gro u nd, w e must a r r es t t he s hip ’s mov e me n t a nd l e t t he s h ip m ak e spee d t hr o ugh th e w a ter co n trary t o t he cu r r ent , in w hich case th e shi p meet s u n der w ate r resi sta n c e. Al l freely mo vi ng sh i ps, n ot b ein g s u b jected t o wind a nd d e a d in th e w a te r , have th e s a m e spee d as th e curren t, w h e th e r th e s hi p s a r e big o r sm al l , loaded o r lig h t. Shi p s n ot free l y m ovi n g, as s hips a t a n ch or o r mo o re d, are subj e c ted t o p res sure exe r t e d b y t he c urr e nt, pres s ure which is dire c t ly propo r t i on a te t o t he expos e d u n de r w ate r are a an d t o th e sq u a r e o f th e cu r re n t v elocit y .

86. I n a st ro n g t i d e w e s e e t h a t s hi p s a t a n c h o r , or m oo r e d t o a s i ngl e p oi n t , a r e h ea d ing i n to t h e t i de ; w he n it is n earl y s l a c k w a t e r ball a s t e d s hi p s w il l be m or e a ff e c t e d b y w in d w hil e t h e l oa de d t a n k e r s s t ill re m ai n headin g in to t h e t id e. W h e n w e ap p r o a c h t h e m o n ob u o y w i th a b all a s t e d t a n k e r in w in d a n d t i d e c o nd i t i o n , t h e dir e c t io n o f t h e loa d e d t a n k e r s , m oo r e d o n s i ngl e p oi n ts n e a r b y , gi v e s u s a n i n di c a t i o n o f t h e di r ecti o n o f t h e c u r re n t . H o w e v er , t h e h e a din g o f t h e b a l laste d s h i p , a f t e r ha v in g b e e n t i e d u p t o t h e b uo y , m a y b e qu i te di ff ere n t from t h e headin g o f t h e loaded s hip

87. Wi n d Ve s s e l s s u ch a s C on t ai n e r a n d R o - R o Shi p s ha v e l a rge f r ee b o a rd an d a r e t h u s m o r e a f f e c t e d b y w ind s . T h i s e x p o s ed ar e a o f t h e s hi p i s al so k no w n a s w ind a g e a rea a s t h e e f f e ct of w in d i s m or e pro m ine n t o v e r i t . T h e w in d e f f e c t o n t h e s a m e s h i p w il l b e d i f f e r e n t a t d i f f e re n t pla c e s, de p e n din g up o n t h e d r a u g h t c ond i t i o n o f t h e s hi p . A w ind w i th f o r ce o f 3 - 4 o n t h e B e a u f o rt s ca l e w il l h a v e s i m i l a r e f f e c t in ligh t c o n dit i o n a s w i th w in d f o r c e o f 7 - 8 w he n t h e s hi p i s d o w n to he r m ar k s . W h e n s h i p i s a t s l o w s pee d s d u ri n g m an e u v erin g o r n e a r t o t h e c o a st , w in d di r e c t i o n is e a sy t o f i n d; b u t t h i s is n o t t h e c a s e w hen o u t a t hi g h s e a. T h e di r e c t i o n of t h e w in d pe r c ei v e d w hen s t a n din g o n d e c k i s i ts re l a t i v e di re ct i o n . T h i s i s t h e r e s ul t a n t of t h e true dir e c t io n o f t h e w in d an d t h e c our se st eere d b y t h e s hi p.

88. EFFECT OF WIND Nee dl e s s to s a y , w ith no tug as s istance, it is w is e to g et this a r e a o f s hi p handl i ng rig h t first time and a lso a p pr e ci at e w ha t the lim i ts are . N a vi g at o rs can us e the w i nd : A s a goo d br a ke As a d e vice for mak i n g a tig h t tur n . T o ma n e u ver com p a r ative l y e a s il y a s l on g a s the w i n d r em a i n s a b o u t two to thr e e po i n ts o n the bo w .

89. Vessel Stop p ed w e ha v e a sh i p o n e v e n k ee l , s t oppe d dea d i n t h e w ate r . I t has t h e f a mi li a r a l l a ft ac c o m mo d a t i o n an d w e w il l a ss u m e , a t t h i s s t a g e , t ha t t h e w i n d i s r ou g h l y o n t h e bea m. W h il st t h e l a r g e a r e a o f su p e r s t r u c t u re an d f unne l o f f e r a considera bl e c r os s -se c t i o n t o t h e w i nd , i t i s a l s o ne c e ss a ry to t a k e i nt o ac c ou n t t h e a r e a o f f r e e b o a rd fr o m f o r w ar d o f t h e b r i d ge t o t h e bo w . O n a VL C C t h i s co u l d be a n a r e a a s l on g a s 28 x 10 m e t e r s . T h e ce n t e r o f e f f o r t o f t h e wi n d ( W ) i s t hu s a ct i n g upo n t he co m bina t i o n o f t he se t w o a r ea s an d i s m uc h f u rt he r f o r w ar d t ha n i s s o m et i m e s e x pe ct e d . T h i s no w needs t o b e c o m p a r e d wi th t he unde r w a t e r p r o f il e o f t h e sh i p an d t h e po s i t i o n o f t h e p i v o t po i nt ( P ). W i t h t h e sh i p i n i t i a l l y s t oppe d i n t h e w at e r t h i s w a s se e n t o be close t o a m i dsh i p s. T h e ce n t e r o f e f f o r t o f t h e wi n d ( W ) an d t he p i v o t po i n t ( P ) a re t h u s q u i te c l os e t o g e t h e r an d t h e r e f o re d o n o t c r e a te a t urnin g i n f l ue n ce upo n t h e sh i p . A l t h o u g h i t wi l l v ary sl i g h t l y f r o m sh i p t o s h i p , g en e r a l l y sp ea k i ng , m o s t w i l l l a y st oppe d w i th t h e w i n d j us t f or w ar d o r j us t a b a f t t h e bea m.

90. Vessel Making He a dway W h e n t he s a m e s h i p i s m ak i ng h e a d w a y , t h e s h i f t o f t h e p i v o t p o i n t u pse ts t h e pre v i o us b a l a n c e a tt a i ne d w h ilst st o ppe d , f i g ure 2 . W it h t h e w i n d o n t h e be a m, t h e c e n t er of ef fo rt o f t h e w i n d r e m a in s w h e r e i t i s b u t th e p i v o t p o i n t mo v e s fo r w ard . T h i s crea t es a s u b st a nt i a l tu r n in g l e v er b e t w e e n P a n d W an d , dep e n d i ng o n w i n d stre n g th, t h e s h i p w il l de v e lo p a s w in g of th e bo w in to th e w in d . At lo w er sp ee ds t h e p iv o t po i n t sh i f ts e v en furt h er fo r w a rd, th e r e b y i mpro v in g t h e w in d 's tu r n i ng le v er a n d e ff e c t . W he n a pp r o a ch i n g a b e r t h with t h e w i nd up on or ab af t t h e beam th a t as s pee d i s r e d uc e d t he e ff e ct o f th e w i n d g e ts p rog r e ss i v e l y g rea te r a nd r e q u i r es c o ns i d er a b l e cor r ecti v e action. W h e n ap pr o a c h in g a b e rth or a b u oy w it h th e w i n d dead a h ea d an d t he sh i p o n an e v e n k e el s u c h a n a p p r o ach sho ul d b e e asi l y c o n trol l e d . E v e n at v ery lo w sp e eds t h e s h i p i s st a b l e an d w il l w is h to st a y w it h th e wi n d ahe ad u ntil st oppe d .

91. Vessel Making Sternway The e f f ec t o f t h e w i n d o n a ship m a ki n g s t e r n w a y is gene r a lly m o r e co m p l e x and l es s pre d ic t ab l e. I n par t t h i s i s due t o t h e add i t i onal co m p lica t i o n o f t rans v ers e t hrus t w he n assoc i ate d w i t h si ng l e sc rew sh i p s. F i gur e 3, w e ha v e a l rea d y seen t ha t w i t h s t ern w a y t h e p i v o t po i nt m o v e s a f t t o a pos i t i o n approx i m ate l y 1 / 4 L f r o m t h e s t er n . Ass u m i n g t hat t h e cen tr e of e f f or t ( W ) r e m a i n s i n t h e sa m e pos i t i on, w i t h t h e w i n d s t ill o n t h e bea m, t h e sh i ft o f p i v o t po i n t ( P) ha s now c reate d a t ota l ly d i f f eren t t urn i n g l e v e r ( W P ) . This wi ll now cause t he s t er n t o s w i n g i nt o t h e w i n d. S o m e cau t i o n i s nece s s a r y , h o w e v e r , as t h e t u rn i n g l e v e r can be qu i t e s m a l l and t h e e f f ec t d i sappoi nt i ng , par ti cu l arl y on e v e n k ee l . In such cases, t h e s t er n m a y on l y par t i a l ly seek t he wi nd , w i t h t h e sh i p m a ki n g s t e r n w a y ' f l opp e d ' ac r os s t h e w i n d. T h i s si t ua t i o n is not he l pe d by t he cen te r of ef f or t ( W ) m o v i n g a f t as t h e w i n d co m es roun d ont o t he quar t er . This, i n t urn , t end s t o r ed u ce t h e m agn i t ude of t h e t urn i n g l e v e r W P. The othe r c o m plica t ing f a c t o r i s t rans v ers e t hrus t . I f t h e w i n d i s on t h e por t be a m , t her e i s e v e r y l i k e l i hoo d t ha t t he t rans v ers e t hrust and ef f e c t of w i n d w ill c o m b i n e and i nde ed ta k e t h e s t er n s m ar t ly i n t o t h e w i n d. I f, ho w e v e r , t h e w i n d is o n t h e s t arb o ar d be a m , it can be seen t ha t t rans v ers e t h rus t and e f f ec t o f w i n d o p pos e each other . W h i ch f or c e w i n s t h e d a y i s t here f or e v er y m uch dependent upon w i n d s t rengt h v ersu s s t er n power , un l e ss y o u k n o w t he sh i p ex c ept i ona l ly w e l l, t h er e m a y be n o guarante e as t o w h i ch w ay t h e s t er n w ill s w i n g w he n bac k i n g.

92. Trim an d Headway So far w e ha v e o nl y c o ns i d er e d a sh i p o n e ve n k e e l. A lar g e tr i m by t h e s t ern m a y ch a n g e t h e s h i p 's w in d h a n d l i ng cha ract er i stics q u it e sub sta ntia l l y . F i g ure 4 sho w s t h e s a m e s h i p , b u t thi s t i me i n b a ll a st and tr i m m e d by th e ste r n . T h e i ncr e a s e i n f r ee b o ard for w ard h as m o ve d W fo r w a r d an d v er y c los e to P. W it h t h e t urn i ng le v er t h us r e d u c e d t h e sh i p i s n o t so i ncl i ne d to r u n u p in t o th e w i n d w it h h ea d w a y , pref e r r in g i n st e a d to fal l o f f , or lay across t h e w i n d . B e c a u s e t h e s h i p i s d i f f i c u l t to k e e p he ad to w in d , s o m e p i l o ts w il l not ac c e p t a sh i p t h a t has an e x cessi v e tr i m by th e stern, p art i cu l ar l y w it h re g a r ds SBM operati o ns .

93. Vess e l He a d to Wind with He a dway T h e m i d d l e d i agra m i n F ig u r e 6 s h o w s a v ess el m a k ing H ea d w ay th r o u g h t h e w a ter, an d H ea d i ng d i rectl y in to t h e W i nd . W i s n ow w e l l fo r w ard o f a m i d s h i p s, a nd i n fact v ery clo s e to P; t h e w i n d i s e x ert i ng n o tu rn i n g m o m e n t, or si d e w a y s f o rce , o n t h e v esse l . A co m pa rati v e l y s m a ll c h an g e i n r e l ati v e w i n d d i r ect i o n ( e it h er b y a lt erat i o n of c o urse , or w in d f l uc tu a t i o n) , w i l l pl a c e t h e w in d o n t h e v esse l' s b o w ; th e w ho l e o f on e s i d e o f the v es s el w il l n ow b e e x po s e d to t h e w i n d , a n d W w il l m o v e a ft as s ho w n in th e s i d e d iag r a m s o f F i g ure 6 . Th e fol l o w in g e ff e cts w il l now be e x per i enc e d : - a) T h e Tu r n in g F orce w il l now d e v e l op a t urn i ng m o m e n t about P, te nd in g to tu rn th e v essel in to th e w in d a g a i n . b) T h e W i n d Fo rce w il l a ls o d e v e l o p a s i de w a y s force on th e v esse l , a w ay from th e e x posed sid e . H ea d to W i n d t he r e fore, t h e v ess e l i s " c o urse st a b l e ", pro v id e d th a t she m a in ta i n s He a d w ay th rou g h th e w a ter. If t he s h i p h as a l ar g e T r i m by t h e s t ern W w il l be furt h er fo r w a rd, w it h a re d uct i o n , or e v en l o ss, o f " c o urse st a b ilit y " . T h i s c a n so m e times r e s u l t i n a r a p i d an d v iol e n t los s of con tro l .

94. Vess e l He a d to Wind with Sternway. Conside r t h e s i t u a t i o n w he n o u r v es s e l r e m a i n s H ea d t o W i n d , bu t no w sta r ts to m a k e S t ern w a y t hro u g h t h e w at e r . W r e ma i ns f o r w a r d , w hi l st P ha s m ov e d a f t , as sh o w n i n t h e m i dd l e d i a g r a m o f f i g ur e 7 : t h e w i n d i s e x er t i n g no t urnin g m o m en t o r s i d e w a y s f o rce. A c o m p a r a t i v el y s m a l l ch an g e i n t h e r e l ati v e d i r ectio n o f t h e wi nd w i l l m o v e W a f t , a s s h o w n i n t h e s i d e d i ag r a ms o f F i g u re 7 : h o w e v e r P r e m a i n s a ft o f W . Th e f o ll o w i n g e f f e cts w i l l n o w be e x perience d :- a) T h e W i n d F o rce wi l l d e v e l o p a st r on g t u r n i n g m o m e n t abou t P, t endin g t o t ur n t h e v esse l 's bo w f urthe r a w a y f r o m t h e w i nd . b) T h e W i n d F o rce w il l de v e l o p a s i de w a y s f o r c e o n t h e v esse l , a w a y f r o m t h e e x po sed s i de . Hea d t o W i n d , a s so o n a s t h e v es s e l s t a r ts t o m a k e S t ern w ay t h r o u g h t h e w ate r , s h e l ose s "co u rse s t a bi l i t y " a n d t h e bo w w i l l pay o f f a w a y f r o m t h e w i nd , somet i m e s q u i te r ap i d l y . I f t h e sh i p ha s a l ar g e Trim b y t h e s t e rn W m a y m o v e f u r t h e r f o r w a r d , p e r hap s q u i c k l y , an d t h e l os s o f "co u rses s t ab i l i t y " is e v e n m o re p r onounce d . T h i s can so m e t i m e s r es u l t i n a r ap i d and vi olen t l os s o f co n tr o l .

95. Vess e l Ste r n to Wind with He a dway T h e m i d d l e d i a g ram o f f i g u r e 8 s h o w s a v essel m a k ing H ea d w ay th ro u g h t h e w a t er , a n d w it h the W i n d direc t ly Ast e rn. P i s fo r w a rd, a l o ng d ist a n c e f r om W , w h ic h i s w e ll a f t. A c o m p arati v e l y s m a l l c ha n g e i n r e l ati v e w in d d i r ect i o n w il l m o v e W fo r w ards as s h o w n i n t h e si d e d i a g r a m s of Fi g u re 8 : h o w e v er W i s still s o me d is t an c e a ba f t P. T h e f o ll o w i ng eff ects w il l now be e x per i enced : - a ) T h e W i n d For c e w i l l d e v e l o p a st r o n g t u rni ng mo m e nt a b o u t P, t e n d i ng to tu rn t he v e s s e l' s S t ern furt h er a w ay from th e W i n d. b ) T h e W i n d F orce w il l d e v e l op a s i d e w a y s fo rce o n t h e v e ss e l , a w ay from th e e x posed si d e . Maki n g H ea d w ay w i t h S t ern t o W i nd , t h e v ess e l l oses "c o u r s e st a bili t y " an d i s dif f i c ul t t o st e er , th i s e f f ec t i s g r e a t e r w he n th ere i s a ls o a fo ll o w in g S e a or S w e ll. If t h e s h i p h as a l ar g e T r i m b y th e S t e r n , W m ay m o v e furt h e r fo r w a rd, an d los s o f " c o urse s t a b ilit y " m ay be g ene rally les s pronou n c ed , but stil l a po te nti a l dan g er .

96. Vessel Stern to Wind making Sternway T h e m i d d l e d i a g r a m o f F i g ure 9 s h o w s a v essel m ak i ng St e r n w ay th r o u g h t h e w a t er , a n d w it h t h e W i n d di r ec t ly Ast e rn. P has m o v e d a f t, fai r l y close to W , w h ic h r e m a i n s e v e n fur t her a f t. A c h an g e i n r e l ati v e w i n d d i r ect i o n w il l e v en t u a ll y m o v e W fo r w ard o f P, as s h o w n i n t h e si d e d i a g ra m s of F i g ure 9 , w it h th e f o ll o w i ng effe cts: - a ) Th e W i n d Fo r c e w il l de v e l o p a tu r n in g m o m e n t a bo u t P, t e nd in g to tu r n the v ess e l' s St er n b a ck int o the W i n d . b ) T h e W i n d F orce w il l d e v e l op a s i d e w a y s fo rce o n t h e v e ss e l , a w ay from th e e x posed si d e . Maki n g St e r n w ay th r o u g h t h e w a t e r, w it h S t ern t o W i n d , t h e v e ss e l i s a g a i n " course sta b le " . If t h e sh i p h as a lar g e T r i m b y th e S t ern W m ay m o v e f u r t h er fo r w ard , gen era l l y im p ro v in g "c o urs e s t a bili t y " ; h o w e v e r w it h such a Tr i m , t h ere i s a l w a y s th e p oss i b i l it y of a n unpre d ict ab l e los s of con tro l .

97. Wind force Wind force d e pend s o n - w i n dage , w i n d vel o ci t y ( w in d pr e ssur e), the a n gle be t w e e n a p pare n t w i nd , an d h e a d ing. W i n d pr e s s ur e i s prop o rti on a l to w i nd ve l oc i ty s qua r ed . T h e C e ntr e o f w i n d p r ess u r e d e pen d s o n the d i str i b u t i o n o f w i n d a g e a l ongs i d e the sh i p.

98. Ship in a beam wind Ship s t o pped T he w in d f orc e i s lar g e. T he re i s no lo n g it ud i na l co m po n e n t . T h e b e h a v io r o f t he sh i p dep e n ds o n t h e c e n te r of w i n d p res s u r e , w h ic h c o u l d b e i n f r on t o f or b e h i n d t h e p o in t of a p pli c a t i o n o f tr a ns v erse resis t a n c e for c e (p iv o t po i n t). Th i s po i n t i s appro x i m a tel y at m ids h i p . Sh i p i s dr i f t i n g a n d t u rni ng ei th e r w a y , de pe ndin g o n t h e rel a ti v e position of th ese po in ts .

99. Ship with headway Point of a p plicatio n of wi n d f o rce is b e hi n d the pivo t poin t. Ship h a s tend e n c y t o s w ing to w a r d s the win d lin e.

100. Ship with sternway Point o f a pplicati o n o f w i nd fo r c e i s i n f ron t o f t h e p i vot point . Ship h a s t e n d e n cy to swing ou t o f the w i n d lin e .

101. Wind from bow quarter Sh i p w i t h hea d w ay The poin t of appli c atio n of wind fo rc e i s behi nd the pivo t point . The s h i p h a s a tend e n c y t o s w ing towar d s the win d line.

102. Ship with sternway Poin t of ap pli c at i o n of wi n d fo r c e is b e h i n d the p i v ot po i n t . Sh i p s wi n g l i n e . h a s t e n d e n cy to towa r ds the wi n d

103. Q U E S T I ON : W H A T A R E THE FOR CE S I N A T U RN ? C AP T R A JIV K V IG

104. T urnin g c i r cle and dynamic stability

105. C ou r se k ee p i n g a b i l it y is re l a t e d to d yn a mic s ta b i l i t y o n s t r ai g h t c o u rse . Sh i p s ca n b e d yn a mic a ll y s t a b l e o r d y n a m i c a ll y un s t a b l e Sh ip is dy n a m i c a ll y s t a b l e if a f te r sm a l l d i s t urb a n c e w i l l r e m a in on t h e n e w s t r ai gh t co u r se s l i g h tl y de v i a t e d fro m t h e p r e vio u s on e w i t hou t u s i n g ru d d er. C AP T R A JIV K V IG

106. Dy n a m i cal l y u n s t a b le s h i p w i l l ma k e a tur nin g ci r cle wit h r u dde r a mi d s hip s Dy n a m i cal l y u n s t a b le s h i p s a r e m o r e di ffi c u lt t o h a n d le , a n d i f t he a m o u n t o f d y n a m i cal inst a bi l it y i s l ar ge , t he y m i g h t b e d a nge r o u s T h e re is , h ow e v e r , no f or c e th at ca n b r in g th e s hi p t o th e or igin al c o u rs e with o u t usin g ru dde r . C AP T R A JIV K V IG

107. I L L US TRA T E D IR E CTI ONAL L Y S TA B LE A N D D IR E CTI ONAL L Y U N S T A B LE S H I P C AP T R A JIV K V IG

108. I L L U S TRAT E D R IF T A N GL E A ND S TAT E I M O C R IT E RI A F O R T A C T IC A L D I AM E T E R A N D AD V A NCE C AP T R A JIV K V IG

109. Initia l t ur ni n g t e st Initia l t ur ni n g a b i l it y i s a mea sur e o f t h e r e a cti o n o f th e s hi p t o s m al l a n g le o f ru d d e r ; I s de fi n e d b y t h e di s tanc e t r a v el l e d b ef o r e r eali z i n g c e r tai n he a d in g d e viati o n w h e n ru d d e r i s ap p l ied . C AP T R A JIV K V IG W HAT IS INI T I A L T U R NI NG A B I L I T Y O F A S H I P A ND I MO CR I T E R I A

110. C AP T R A JIV K V IG

111. C AP T R A JIV K V IG

112. S h ip is mo v i n g al o n g t h e c u r v i l i n e a r p at h w i th t h e c e n t r e a t p oi n t O . T h e d i s t a n c e b e t w e e n t h e c e n t r e o f c u r v a t u re a n d t h e cen t re o f g r a v i t y of t h e s h ip is r a diu s o f i n s ta n tan eo u s tu r n . S h ip ’ s c e n t rep l an e d e via te s f r o m t h e tan g e n t t o t h e p a t h of t h e ce n t r e of g r a v i t y b y t h e d r i f t an g l e. C AP T R A JIV K V IG • Th e l i n e p e rpe n dic u l a r t o t h e s h i p’ s ce n t r ep l a n e t h ro u g h th e c e n t r e o f ro t a t i on, m a rk s p iv o t po i n t ( P P). A t t h is p o i nt , t h e r e i s n o t r ans v e rse v e l o ci t y in t u r n i ng ; f o r pe o p l e o n b oa rd it ap p e a r s th a t t h e s h i p r ot a t e s a ro u n d t h is p oi n t (Fi g . 2 . 8). T r an s v e rse vel oci t y is gre a t e s t a t s te r n . • •

113. q u e s tio n : C o m p a r e t h e t u rn i n g charac t e ris t i c s w r f l e n g th , b e a m o f sh i p s Tw o s h i p s o f t h e s a m e l e n g t h ha ve n e arl y t h e s am e T r a n s f e r T a c t i ca l D i am e te r f o r bo th s h i p s is al m o st t h e s a me R a di u s of t he s t e a dy t urn i n g c i r c l e i s m u ch sm a ller f o r t a n k er Dr i f t a ng l e i s m u ch lar g e r f or tan k e r P i v o t p o i n t i s c l o s e r to t h e b ow i n t a n k er C AP T R A JIV K V IG C o m p a r i s o n of Tu r n i n g c h a r a c t erist i c s o f Ful l a n d Sl en d er s h ip

114. E ff e c t o f s h i p s i ze on tu r n i n g p er fo r m a n c e C AP T R A JIV K V IG Tu r n i n g c h a r ac t e r i s t i cs d e p en d o n t h e s h i p s i z e . Th e t ac ti c a l d i a m e t e r i s n o t p r o po r ti on a l to t h e d i s p l a c e me n t o f t h e s h i p b u t r e l at i v e t a c ti c a l diam e t e r D/ L i s e q u a l f o r s h i p s g e o m e t r i c a l l y s i m il a r o f diff e r e n t s i z e a s w e ll a s f o r f u ll - s c a le s h i p a n d it s m o d e l .

115. E f f e c t o f s hi p p a r a m et e r s o n tu rnin g a n d co u r s e k e e pin g Man o e u v r i n g p e r f or ma n c e d e p e n d s on s hi p fo r m a n d p r op o r t i o ns . Ta b l e b el o w sh o ws the e f f e c t of s h i p p e r f or manc e o n m an o e u v r ing c h a r a c t e r isti c s C AP T R A JIV K V IG

116. Sh i p h a n d li n g: T e r m s T u r nin g C i r c l e : T h e p a t h d es c r ib e d b y a s h ip ’ s pi v o t p oi n t as i t e x e c u te s a 360° tu r n . T ac t i cal D ia m ete r (180°) Final Di a m et e r ( 3 6 0°)

117. Kic k Final Di a m et e r T a c t i c al D ia m e te r T u r nin g C i r c l e Sh i p h a n d li n g: T e r m s

118. Ad v an c e Di s t a n c e g a i n e d t o w a r d t h e di r e c t ion o f t h e o r i g i n a l c o u r s e af t e r t h e r u d d e r i s p u t o v e r. T r an sf e r Di s t a n c e g a i n e d p e r p e n di cu l ar t o t h e o r i g i n a l c o u r s e af t e r t h e r u d d e r i s p u t o v e r. Sh i p h a n d li n g: T e r m s Ad v a n c e a n d T r an s f er

119. A d v an c e & T r a n s f er 9 ° T u r n Kic k Advan c e T ra n sfe r Sh i p h a n d li n g: T e r m s

120. A d v an c e & T r a ns f e r 180 ° T u r n Kic k Advan c e Tr a nsfe r Sh i p h a n d li n g: T e r m s

121. A d v an c e & T r a ns f e r 360 ° T u r n Kic k Advance T ra n sfe r Sh i p h a n d li n g: T e r m s

122. Sh i p h a n d li n g: T e r m s T u r nin g C i r c l e : T h e p a t h d es c r ib e d b y a s h ip ’ s pi v o t p oi n t as i t e x e c u te s a 360° tu r n . T ac t i cal D ia m ete r (180°) Final Di a m et e r ( 3 6 0°)

123. T u r n i n g c i r c l e The turnin g ci r cle of a v essel is t he ci r cle th e v essel wil l d escribe w hen her helm is pu t , ha r d o v er t o s t a r boa r d or ha r d o v er t o por t , usual l y wit h her eng i ne s full ahead. The de t erminat i on of th e turn i n g ci r cle of a v es s el is normal l y carried out dur i ng th e sea trial s of th e v essel prio r t o hand o v er f r om th e builder s t o th e o wners. The turnin g ci r cle, t i g h t er w i t h s t opping d i s t ance , a r e place d on boa r d of th e v essel in t he tr i a l papers , so tha t th e y can b e c o nsul t ed b y t he sh i p ’ s Mas t e r , t he w a t ch officers an d e v entual l y th e pilot s . Wit h r e g a r d t o th e turnin g ci r cle th e f oll o win g s t a t em e nt s a r e u s ual l y s t a t ed in the tr i a l papers: - The a d v anc e of th e v essel. The t r ans f er of th e v essel. The tact i cal diame t er tha t th e v es s el scribe s . The final d iame t er tha t th e v essel has scribed.

124. T u rni n g c i r c le T urnin g ci r cle in f ormation f r om trials or e stima t es f or v ario us lo a ded/ballast conditions; T est condition r esults r eflec t ing ‘ a dv anc e’ and ‘ t r ans f e r ’ and the sta t ed max i mum rud d er an g le emp l o y ed in th e t es t , t ogether with t i me s and spe e ds a t 90° , 180° , 27 0° and 360° ; details shoul d be in diag r amm a tic f ormat with shi p ’ s outline. T urnin g ci r cle mane u v er is th e mane u v er t o b e p e r f ormed t o both sta r bo a r d and por t with 35 ° rud d er an g le or the m a xim um rud d er an g le p e rmissible at th e t est spe e d, f oll o win g a s t ea d y a p p r oa c h with ze r o y a w r a t e. A shi p ’ s tur n ing ci r cle is th e path f oll o w ed b y th e shi p ’ s p i v ot poin t w hen makin g a 360 ° turn with o u t r eturning t o th e initia l course. I f th e v essel is fi t t ed with a ri g h t -hand fi x ed p r op ell e r , she w ould b e nef i t f r om th e t r an s v erse thrus t ef f ec t , and her t urnin g ci r cle, in gen e r al , wil l be quic k er and ti g h t er w hen turnin g t o por t than t o sta r bo a r d. A v essel lis t ed wil l turn mo r e r eadi l y t o w a r ds her hi g h side with smaller turnin g ci r cle on th at side.

125. The diame t er of th e turn i n g ci r cle is eq u a l t o ab o u t 4 shi p ’ s len g th s ( 4L). I n posit i on 1 , th e helm is p u t ha r d t o sta r b o a r d a n d th e v ess e l wil l f i rst m o v e t o p o rt of her in i t i a l co u rse. The v essel als o start t o tur n t o sta r b o a r d. D u e t o the posit i on of her tur n in g poin t ( p i v ot poin t ) a t abo u t ¼ f r om th e b o w , th e b o w wil l ha r d l y b e m o vin g in side th e i n it i a l co u rse b u t t he a f t of t he v ess e l will s wi n g t o p or t . On l y in p o sit i on 4, a f t er 4 shi p ’ s len g th s on th e i n it i a l co u rse, t he a f t o f th e v ess e l will sta rt t o m o v e t o th e in side of th e i n it i a l co u rse. I n posit i on 5 , th e shi p ’ s co u rse wil l h a v e chan g e d abo u t 90° t o sta r b o a r d. C on c lusi o n: I f the r e is a n o b stacle st r a i g ht ahe a d of th e v ess e l at a d i sta nc e o f less t han 4 shi p ’ s len g ths , this o b stacle can no t b e a v oided b y a helm act i on on l y . The port q u ar ter o f th e v ess e l wil l hit t he o b stacle.

126. A d v a n c e - A d v a nc e is the dis t a nc e t r a v e l l e d in the di r e c t ion of th e orig i na l course b y th e m i dship poin t of a ship f r om the po s ition at w h i ch t he rudder o r der is g i v en t o the po s ition at w h i ch t he h e ading has ch a nged 90 ° f r om the original c o urs e ., measu r ed f r om the point w h e r e the rudder is first pu t o v er a n d should not e x ce e d 4 . 5 ship l e ng t hs T r a n s f e r - T r ans f e r is th e am o u n t of dista nc e g ain e d t o w a r ds the n e w c o urs e (sh o w n h e r e f or 9 ° h e ading ch a nge). T a c t i ca l D i a m e t e r - T ac t ical diamet e r is the dis t a nce t r a v e l l e d b y t he midshi p poin t of a ship f r om the po s ition at w h i ch the rudder o r der is g i v en t o the positio n a t w h i ch th e h e a d i n g has changed 18 0° f r om the original c o urs e . I t i s measu r ed in a di r ection perp e ndicula r t o the original h e ading of the ship.. F i n a l D i a m e t e r - Final diamet e r is the dis t a nce perp e ndicula r t o the original c o urs e measu r ed f r om th e 180 ° poin t th r ou g h 36 ° (s h o w n h e r e f or st e a d y turn i n g r a d i u s, R). P i v o t P o i n t - A shi p ’s p iv ot point is a point on the cen t e r l i n e a bou t w h i ch the ship t urn s w h e n the rudder is pu t o v e r . D r if t A n g l e - D r i ft a n g l e is an a n g l e at a n y poin t on the turn i n g ci r cle b e t w ee n th e i n te rs e c t ion of th e t a nge n t at that point and the shi p ’s k e e l l i n e .

127. M a x . Ad v a n c e Ad v an c e R e a c h K i c k T ra n s f e r M a x . T r a ns f e r T a c t i c a l D i am e t e r F i n a l D i am e t e r Tu r n i n g C i r c l e ̓ ̒ R e g a r din g th e m e th o d of t u r ni n g c i r c l e , w h i c h is m e a s u r ed d u r i n g a s ea t rial a n d d i s p l a y ed in t h e b r i d g e , in t h e e v e n t t h at i t i s a c o n t a i n er s h i p : M a x . A d v a n c e o r a M a x . T r a n sf er e t c. , t h e Fi n al D iam e t e r at t h e t i me w h e n r u dd e r is s t ee r e d t o full, is g e n e r al l y 3 . 5 t o 4 t i m es t h at of t h e h ull le n g th . H owe v e r , this i n f o rm a t ion is b a s e d o n a v e ss el c arr y in g b a l la s t ( ball a s t c o n dit io n) a n d m o s t of t h em n a v i g a t e a t a s p eed of a pp r o x im a t ely 1 5 k t s . T h er e is n o d a t a a v a i la b le f or w h en a v e ss el is f ul l y loa d e d a n d a t full s p ee d . T he s e s pe c i f icat io n s a r e i n v al u a b l e f o r t h e h e l m s m an in t h e e v ent of r a p i d t ur n i n g a t S / B b e i n g ne c e s s a ry (e . g . t o p r e v ent a c ol l i s ion o r g r o un d i n g ) . M a n e u v er i ng w i t h r u d d er H a r d O v er a t F u l l S p ee d is n o t r e ali st i c be c a u s e t he a b o v e -d e s c r i b e d t r o ub l e m a y o cc u r . I n s u c h a s i t u a t i o n , in o r der t o c a r r y o u t a v oi d a n c e m a ne u v e r i n g s a f e l y a t fu l l s p ee d a n d t o r em ain a t a s a f e d is t a n c e f r o m t he s h o r e, t a k e i n t o a c c o u nt t he s e a a r e a w h i l e p a y i n g c a r e fu l a tt en t i on t o r a t e - o f - t u r n s p ee d .

128. A d v a n c e : 2. 1 m i l es F i na l D i a m e t er : 4. 2 m il es 1 8 m i n . ̓ ̓ F o c u s on t h e r a t e - o f- t u r n s p ee d d ur i ng t h e s h i p ' s h u ll t u r n i ng r o u n d m o me nt Al th o u g h it w i l l di f f er d e p e n d i n g on a s h i p 's h u l l c o n s t r u c t io n , s p e e d a n d s t a bil i t y , t h e r a t e - o f - t u rn s p e e d , whi c h n e i t h er c a u s e s d e c ele r a t i o n or e n g in e h ar m , is a p p r o x im a t ely 1 d e g r e es p e r mi n ut e . C o nd i t io n s ɿ S t e er a t a c o n t ro l l e d li m it of 2 2 k t s a n d 10 d e g r e e s p e r m i nut e f or r a t e - o f- tu rn s p e e d . - Ti me r e qu i r e d f o r t ur n i n g r o u n d a t 3 6 d e g r ee s ʹ 3 6 m i nu t e s ( . 6 h o u r s ) - R u nn i n g d i s t a n c e ov er 3 6 m i nu t e s ʹ 1 3 . 2 n a u t ic al m i l e s ( 2 2 k n o t s ͇ 5 V S O 3 B U F ̍ ̌ E F H S FF N J O V U F T 4 I J Q T T Q F F E L U T 0. 6 h o u r s ʣ F or e x a m p le, in th e e v e n t o f a v oi din g a c r o ss in g v e ss e l , it is n e c e ss ary t o c o n s id e r t h e s e a a r ea a n d t ime r e q ui r ed f or t u r n i n g r o u n d at 9 d e g r e e s . O th e r w i s e, c a l c ul a t e e s t im a t ed s i z e of s ea a r e a , r e q ui r ed f or o n e tu r nin g r o u nd, b y d r a w in g a n d f o r m u la a n d c h e c kin g i t b y d r aw i n g i t on t h e n a u t i c al c h a r t . To t a l r u n : 13 . 2 m i le ʢ ̏ ̒ ෼ʣ T r an s fe r : 2 .1 m i l es 9 m i n . 2 7 m i n .

129. Gene r a l r ema r ks The turnin g ci r cle conduc t ed in shall o w w a t er w ill b e conside r ab l y inc r ease com p a r ed with a turnin g ci r cle condu c t ed in deep w a t e r . T urnin g a v essel with h e r h e l m ha r d o v er wil l cause th e v esse l ’ s speed t o dec r ease conside r ab l y . A de e p laden v essel p e r f orming a turnin g ci r cle (e.g. in c a se of man o v e r b o a r d) wil l e x perience les s ef f ect f r om the wind or sea condit i on th a n in li g ht ballas t condition. A v essel trimmed b y th e s t ern wil l gene r al l y s t eer mo r e easi l y bu t th e tac t ica l diame t er of the turn wil l be e x pec t ed t o inc r ease. A v essel trimmed b y th e h e ad wil l dec r ease th e size of th e turn b u t wil l b e mo r e dif f ic ul t t o s t ee r . A v essel condu c tin g a turnin g ci r cle with a lis t c o uld n o rmal l y b e del ay ed.

130. T urnin g t o w a r ds a lis t w ould normal l y gene r a t e a la r g e turnin g ci r cle. T urnin g a w a y f r om a lis t w ould normal l y gene r a t e a smaller t urnin g ci r cle. A v essel t ends t o heel t o w a r ds th e di r ection of turn once helm is ap plied. A v essel turnin g with an e xis t ing lis t and no t b e ing in an u p ri g ht p o sition coul d in shall o w w a t ers e x perience an inc r ease in d r au g h t . The typ e or rud d er can h a v e influence on th e tu r nin g ci r cle of a v essel. A n a r r ow b eam v essel normal l y ma k e a ti g h t er t urnin g ci r cle th e n a wide b e a m ci r cle. A v essel equip p e d w ith a ri g ht hand f i x ed p r opeller w ould normal l y turn ti g h t er t o p o rt than sta r b o a r d.

131. F a c to r s w i l l af f e c t t h e r a t e o f t u r n a n d t h e s i z e o f t u r n i n g c i r c l e Structu r a l design a n d leng t h of th e v es s el. D r au g ht a n d t r im of v es s el. Siz e an d mo t iv e p o w er of mai n machiner y . D i str i butio n an d s t o w ag e of ca r go. E v en k eel or ca r ry i n g a li s t . P os i tio n o f turnin g in r elat ion to th e a v ailabl e depth of w a t e r . Amou n t o f rudder an g l e r equi r ed to comple t e th e turn. Ex t ernal f o r ces af f ecting th e d r ift a n g le.

132. 1 . S t r u c t u r a l d e s i g n a n d l e n g t h . The longe r th e sh i p gene r al l y , th e g r ea t er th e turnin g ci r cle . The typ e of r udde r an d t he r esulting s t eer i n g ef f ect wil l decide t he final diame t e r , wit h t he clea r anc e bet w een rudder and hull h a ving a majo r influence . T h e s m alle r th e clea r anc e bet w een rudder an d hull th e mo r e ef f ect i v e th e turnin g actio n . 2 . D r a u g h t a n d t r i m . The deeper a v essel lie s in t he w a t e r , th e mo r e slugg i s h wil l b e her r esponse to th e helm. O n th e other hand, the supe r structu r e of a v es s el in a li g ht condition an d shall o w in d r au g ht i s cons i de r ab l y influenced b y th e wind . The t r im of a v es s el wil l influence th e s ize o f th e turnin g ci r cle in su c h a w a y tha t it wil l dec r ease if the v es s el is trimme d b y th e head. Ho w e v e r , v es s els n ormal l y tri m b y the s t ern f or bet ter s t ee r ag e an d imp r o v ed hea d w a y an d i t w ould be unusua l f or a v es s el t o b e trimme d in n ormal c i r cum s tance s b y the head.

133. M o t iv e p o w e r . The r elation bet w een p o w er an d d i spla c ement w i ll af f ect t he turnin g c i r cle per f ormance of a n y v es s el in th e s am e w a y tha t a li g ht speedboat has g r ea t er a c cele r atio n tha n a he a vi l y lade n o r e ca rr i e r . I t should b e r emembe r ed tha t th e rudder is on l y ef f ect i v e w hen the r e is a flow of w a t er pas t it . The turnin g ci r cle wil l t he r e f o r e n o t inc r ease b y a n y conside r abl e ma r gi n wit h a n inc r ease in speed, becaus e t he s t eer i n g ef f ect is inc r eased o v er th e same period . (The rudder s t ee r ing ef f ect wil l inc r ea s e wit h th e squa r e of th e fl o w of w a t er pas t th e r udd e r .) D i s t r i b u t i o n a nd s t o w a g e o f c a r g o . Ge n e r al l y thi s wi l l n ot af f ect t h e turnin g ci r cle in a n y w a y , b u t th e v es s el wil l r es p ond mo r e r eadi l y if loa d s a r e s to w ed amids hips ins t ead of a t t he e x t r emitie s . M e r chant sh i p design tends to di s tribu t e w ei g ht t h r ou g hout th e v es s e l ’ s le n g t h . The r eader m a y b e abl e t o im a gin e a v es s el loade d he a vi l y f o r e an d aft r esponding sl o w l y an d slug gish l y to th e helm.

134. E v e n k e e l o r li s t e d o v e r . A ne w v es s el w hen en g age d on tri a l s wil l b e on a n e v en k eel when ca r ry i n g out turnin g c i r cles f or r eco r ding th e s hi p ’ s dat a . This con dition of e v en k eel can n o t , h o w e v e r , a l w a y s be gua r an t eed once th e v es s el is comm i s s ioned an d loa d ed. I f a v es s el is ca r ry i n g a li s t , it can b e e xpec ted to ma k e a la r ge r turnin g c i r cle when turnin g t o w a r ds th e l i s t , an d v i c e- v ersa. A v a i l a b l e d e p t h of w a t e r . The m ajorit y of v es s els, depending on hull f orm, wil l e xperi ence g r ea t er r es i stance when n a vi g atin g in shall o w w a t e r . A f orm of in t e r actio n ta k es plac e be t w een th e hull an d t he sea be d w hi c h m a y r esult in th e v es s el y a win g an d b ecoming di fficult to s t ee r . Sh e m a y ta k e lon g er t o r es p ond t o helm m o v emen t , p r obab l y inc r eas i n g th e a d v anc e of th e turnin g ci r cle, a s w ell a s inc r eas i n g o v er th e t r ans f e r . The cor r esponding final diame t er wil l b e inc r eased r et r ospe c t iv e l y .

135. R u dd e r a n g l e . P r obab l y th e mos t s i g n if i cant f ac t or af f ecting th e tu r ning ci r cle is th e r udde r an g l e . The optimum is o n e w hi c h wil l cause maximu m turnin g ef f ect without cau s ing e x ce s s i v e d r ag . I f a small rudder an g l e is empl o y ed, a la r g e turnin g ci r cle wil l r es u l t , wit h little los s of speed. H ow e v e r , when a la r g e rudder an g l e is empl o y ed, the n , al t hou g h a ti g h t er turnin g ci r cle m a y b e e xperi enced, thi s w ill be accompanie d b y a los s of speed. D r if t a n g l e a nd i n f l u e nc i n g f o r c e s . Whe n a v essel r espo n ds t o helm m o v emen t , it is n o rmal f or th e s t ern of th e v es s el to t ra v er s e in opposing Motio n . Alth o u gh th e b o w m o v ement is w hat is des i r ed, the r es u lta n t m otion of th e v es s el is one of c r abbin g i n a s i de w a y s di r ection, a t a n an g l e of dr i f t . Whe n comple t ing a turnin g ci r cle, becaus e of thi s an g l e of dr i f t , th e s t ern quar t ers a r e outside th e turning c i r cle a r ea w hile th e bo w a r ea i s in s ide the turnin g ci r cle. Studie s h a v e sh o wn that the ‘ p i v ot point’ of t he v es s el in most ca s es d e s c r i bes the ci r cum f e r ence of t he turnin g c i r cle.

136. H e a d w ay m o vi n g f or w a r d t h r u t h e w a t e r S t e r n w ay m o vi n g b ack w ar d s t h r u t h e wa t e r B a r e S t eer a g ew ay t h e m i n i m um s p e e d a sh ip c a n pr o c e e d a n d s t i l l ma i n t a in c o u r s e u si n g t h e r u d d e rs Sh i p h a n d li n g: T e r m s

137. S h ip Ah e ad P ro p e l l e r Ah e ad Rud de r A m i d s h ip s Sh i p h a n d li n g: S i n gl e S c r e w S h ip s

138. S h ip A s t e r n P ro p e l l e r As t e r n Rud de r A m i d s h ip s S h i p f ollo w s t h e r u dd e r: S h i p w ill t e nd i nt o t h e w i nd: S h i p w ill t e nd t o p or t v e r y e asil y S h i p d o e s n o t t e nd t o s t a r b o a r d e asil y Sh i p h a n d li n g: S i n gl e S c r e w S h ip s

139. S h ip Ah e ad P ro p e l l e r As t e r n Rud de r A m i d s h ip s Sh i p h a n d li n g: S i n gl e S c r e w S h ip s

140. S h i p A he ad B o t h P ro p e ll e r s A he ad Sh i p h a n d li n g: T w in S c r e w Sh ip s

141. S h i p A he ad O n e P r o pe ll e r Traili n g C o u nte r act wi t h r u dd e r Sh i p h a n d li n g: T w in S c r e w Sh ip s

142. S h i p As t e r n O n e P r o pe ll e r Traili n g C o u nte r act wi t h r u dd e r Sh i p h a n d li n g: T w in S c r e w Sh ip s

143. S h ip A he ad B o t h P ro p e ll e r s A he ad D i ff e r e n t S pee d s C o u nte r act wi t h r u dd e r Sh i p h a n d li n g: T w in S c r e w Sh ip s

144. P ro p e l l e r s Spl it Sh i p h a n d li n g: T w in S c r e w Sh ip s

145. S ing l e H e a d l in e S i m pl e s t T i e - u p B e s t t o a l lo w t u g t o push o r p u l l o n l y N ot g o od i f c o m pl e x t u g ma n e u v e rs r e q u i r e d. Sh i p h a n d li n g: T u g T i e - U p s

146. D o u b l e H e a d l in e N ot a s simpl e Al lo ws t u g t o push o r p u l l a n d c o m pl e x t u g ma n e u v e rs Sh i p h a n d li n g: T u g T i e - U p s

147. P o w er Mo s t v e r s a t i l e t i e - u p G o o d f o r g e n e r a l p u r p o s e u s e Ho ld s t u g s e cu r e l y t o sh ip. Sh i p h a n d li n g: T u g T i e - U p s

148. R e c o v e r y M an e u v e r s W i l li am so n Tu r n And e r s on Tu r n Ra c e T r a c k Y - T u r n Sh i p h a n d li n g: M a n O v e r bo a r d R ec o v e ry

149. E a s i e s t M e t h o d ? D a y li g h t: An d e r s on N i ght : W i lli am s on S ub s : Y b a c ki n g C a rr i e r s : R a c e tr a c k B o at / H e l o? Sh i p h a n d li n g: M a n O v e r bo a r d R ec o v e ry

150. R e c o v e r y c o n s i d e r a t i o n s H e li c op t e r a v e r a g e t i m e t o r e a d y fo r t a k e of f i s 10 - 12 m i n s S m a l l b o at a v e r a g e t i m e t o l a un c h 6 - 8 m i n s S h i p f as t e s t m e t h o d Sh i p h a n d li n g: M a n O v e r bo a r d R ec o v e ry

151. Rig h t F u ll Rudd e r All E n gin e s Ah e ad F ul l Kic ks S te r n A w ay Man O v e r b o a r d S t a r b o a r d Si d e Sh i p h a n d li n g: M a n O v e r bo a r d R ec o v e ry

152. W il liam s on T u r n S h i f t R u dd e r W h e n 60° O f f C o u r s e Sh i p h a n d li n g: M a n O v e r bo a r d R ec o v e ry

153. man e u v e r in g W il l i a m s on p o r t s t arb o a rd - s l ow - g o o d f o r n i g h t o r l ow v i s 6 deg Sh i p h a n d li n g: M a n O v e r bo a r d R ec o v e ry

154. A n d er s on T u r n Sh i p h a n d li n g: M a n O v e r bo a r d R ec o v e ry

155. man e u v e r in g A n d er s on p o r t s t arb o a rd - fast e st - m o s t sk ill Sh i p h a n d li n g: M a n O v e r bo a r d R ec o v e ry

156. R a c e t r a c k T u r n Sh i p h a n d li n g: M a n O v e r bo a r d R ec o v e ry

157. man e u v e r in g Ra c e tr a c k p o r t st arb o a rd - hig h sp eed - ea s i e r ap p r o a ch Sh i p h a n d li n g: M a n O v e r bo a r d R ec o v e ry

158. Y - T u r n Sh i p h a n d li n g: M a n O v e r bo a r d R ec o v e ry

159. man e u v e r in g Y - b a c k i ng p o o r co n tro l k eep s sh i p c l o s e to m an Sh i p h a n d li n g: M a n O v e r bo a r d R ec o v e ry

160. man e u v e r in g t e ar d r op p o r t s t arb o a rd - C a rr i e r s mo d i fi ed r a c e tr a ck Sh i p h a n d li n g: M a n O v e r bo a r d R ec o v e ry

161. S t oppin g d i stan c e and forces for stopping the ship

162. STOPP I NG OF S H IPS C AP T R A JIV K V IG

163. S t oppi n g dist a n c e – S t oppi n g time The s t op pin g distance is th e distance th a t a v essel with h e r rudder amidsh i ps and her e ngin e fu l l ahe a d, wil l run f r om the mom e n t her engine a r e p u t as t ern unti l she comes t o a comple t e r est ( s t op) o v er the g r ound. The t i m e ta k en t o com p le t e th i s is call s t op pin g tim e . S t op ping distance and s t op ping t ime mus t :- B e e x p r essed in ship ’ s length s ( L ) or m . and th e s t op pin g tim e in min u t e and second . B e clea r l y e x p r essed on th e bridge. The w a t er r esistan ce, a t a c o nstan t sp e ed is equal t o th e po w er of the engine and , a s a r ou g h esti ma t e, th at w a t er r esistan c e is p r oportion a l t o th e s q ua r e of th e speed ( V ²).

164. S t oppin g di s tan c e – S t oppin g time Gene r a l r ema r ks S u p p ose a v essel wi t h a speed of 16 knot s w i t h her eng i ne s a t th e a v e r ag e p o w er of 100%. The w a t er r es i sta nc e in tha t case is a lso eq u a l t o 100%. The e n g i n e s a r e s t opped a n d the v ess e l is cont inui n g t o m o v e on her o w n i n ert ia wi t h h er h elm a t midships. W h en th e v ess e l has sl o w d o w n to 8 k n ots th e w a t er r es i sta nc e wil l b e equal t o 25% of the iner t ia w a t er r esis t anc e . The s t opping d i sta nc e depends f or a g r e a t deal on th e p r op o rtion b e t w e e n th e p r opeller p ow er Ahe a d a n d As ter n . The p o w er of a tu r bin e s t eam e ng i ne , w o r ki n g as t ern is abo u t 70% of its p o w er w o r ki n g ahe a d. W h en app l yin g as tern p r op ulsion t o s t op a ship, th e sh i p m a y b y consid e r ed a s be ing s t opped w hen t he w a k e r e a c h es t he middl e of th e ship.

165. Whe n t he s t opping t i m e an d th e speed of a v essel a r e kn o wn , it is quit ea s y t o de t er m ine th e s t opping di s tance. Whe n con s i d ering th e s t opping d i s t ance , t a k e in t o accoun t th e d i s t anc e r a n f r om th e t i m e th e speed T eleg r ap h is pu t on full as t ern an d tha t th e p r opeller actual l y s t ar t t o tur n as t ern. The engineer is n o t a lwa y s close t o th e manoe u vring boa r d and w hale minu t e can e laps e be f o r e th e p r opell e r actual l y turn s in r e v erse d i r ection. Element s such a s th e wi n d, th e s t a t e of th e sea, th e dep t h of w a t er should b e t a k en in t o ac c ount w hen consi d ering th e s t opping di s tanc e an d th e s t opping time. K eep in min d tha t w hen as t ern p o w er is applied , th e v essel wil l n ot s t a y on her ori g inal course bu t th e b o w wil l tur n ei t her t o s t a r boa r d or t o por t depen d ing on th e t y p e of p r opeller used. F or in s tance , wi t h a ri g ht hand fi x ed p r opell e r , th e as t ern w i l l m o v e t o por t an d the b o w t o s t a r boa r d. Whe n t he v essel has co m e t o com p le t e r es t , th e v essel m a y w ell h a v e turne d o v er 90 ° .

166. S t opp i n g d i s t a nc e o f s h i p s A s w e al l kno w , ship li k e a n y o t her t r ansp o rt ut i lity do e s no t h a v e b r a k es t o ma k e the m s t op immedia t e l y . Whe n th e engine is g i v en s t op o r de r , th e ship w ill continue m o ving in th e same d i r ection due t o inertia and wil l c o m e t o s t op af t er m o ving f or so m e distance. Ev e r y s h ip h a s t h r e e d if f e r e n t s t o p p i n g d i s t a n c e s d e p e nd i n g on : In e rtia S t op . C r ash s t op. R udde r c y cle s t op .

167. I n e r ti a S t o p W hen th e engine of the ship is s t op p e d, th e sh i p wil l c onti nu e m o ving in the same di r ection f or so m e mo r e distance due t o inerti a. He r e n o as t ern command is g i v en (used t o p r oduce “b r akin g ef f ec t ” f or ships), and hence sh i p wil l t r a v el mo r e distance in th e inertia s t op met hod. The distance in mile s m a y on l y b e t enth of the initial spe e d f or li g ht ship s, b u t mo r e th a n half the spe e d f or de e p l y lo a ded s hi ps. I. e. if ship speed 1 kt s f or laden ship th e inertia s t op wil l b e ab o u t 5 N .M . if ship speed 10 kt s f or li g ht loaded ship th e in e rtia s t op m a y 1 /10 of in i ti a l spe e d w hi c h is one N .M. S t op pin g a b ility The t r ac k r each in th e full a s t ern s t op ping test should no t e x ceed 1 5 ship lengths. H o w e v e r , th i s v alu e m a y be modi f ied b y th e A dminist r at i on w he r e ships of la r ge. Displace men t ma k e th i s cri t erion im p r ac t ica bl e, b u t shoul d in n o case e x ce e d 20 ship lengths.

168. C r a s h s t o p C r ash s t op is usual l y th e t erm used w hen the ship has t o sudden s t op in em e r genc y situati o n . He r e th e engine, w hi c h is m o ving in an ahead di r ection is g i v en an o r der f or f u l l as t ern, l e a ving th e rud d er in th e mi d s hip position t o s t op th e sh i p wit hin minim u m distance and shor t est p o ssible t i me . T his s t ops or r educ e s th e sp e ed of the v essel he a ding t o w a r ds th e collision c o urse. C r ash mane u v ering is turnin g th e engine in opposi t e di r ection t o r educe the he a ding speed of the ship . Af t er c ertain t i me , th e ship s t ops a n d s tarts st r eaming in as t ern d i r ection. This is d one b y s u p p l ying starting ai r a t a bout 3 b a rs f r om the air r ec e i v er t o th e engine. The s t op pin g ai r is kn ow n a s the b r a k e ai r . The b r a k e ai r w hen sudden injec t ed inside th e engine c y linde r , wil l tr y t o r esist the mo t ion of the p i s t on and th e r ot a ti o n of the c r an k sha f t and p r op e lle r .

169. C r a s h s t o p p r oce d u r e Whe n t he r e is a n emerg e nc y li k e colli s ion, g r ound i n g e t c. th e cont r ols a r e t r ans f er r ed immed i a t e l y in t o th e Engin e r oom cont r ols. The bridg e wil l g i v e as t ern d i r ecti o n in t he t eleg r aph , ackn o w ledg e th e same. Whe n t he t eleg r ap h is ackn o w ledge d on l y th e s t artin g ai r c a m wil l r e v erse i t s d i r ection bu t th e fuel cam wil l r emain in i t s running posi t ion due t o running d i r ection in t e r loc k si n ce engine is s t i l l running in th e ahea d di r ection The fuel l e v er in t he eng i n e con t r ol r o o m is b r ou g ht t o ‘ ’ A s s o on a s th e RP M of t he eng i n e d r ops belo w 4 % of th e Maxim u m C o nt i nuous R ati n g of th e engine, g iv e b r eak ai r f ew t i me s i n short t i m e f r am e . The b r eak ai r wil l i njec t wit h as t ern t iming se t t i n g in s i d e t he ahea d m o v i n g pis t on w hich wil l r es i st th e pis t on mot i on . S ince fuel wil l no t inject unt i l running d i r ecti o n in t e r loc k opens, a s so o n a s th e rpm d r ops nea r t o Ze r o, g iv e f u el an d ai r kic k b y bringin g fuel l e v er t o minimum s t ar t set t ing. Whe n carrying out C r as h Mane u v ering, some sa f eties nee d t o b e b ypassed t o a v oid tr i ppin g of eng i n e in mid of eme r gen c y . Whe n t he s hip s t ops an d s i tuat i on is unde r cont r ol, a detailed Mai n engine in s pe c t i on is t o b e carried out w hen the r e is a chan c e.

170. R u d de r c y c l e A w ell t r i ed method of u s ing th e en g ine to b r a k e th e f or w a r d p r o g r ess of th e v es s el is t o init i al l y k eep th e p r opeller goin g ahea d bu t r educ i n g the r e v olut ions an d turnin g th e helm f r om o ne s i de to th e other to c r ea t e a rudder d r ag. Whe n hea d w a y has bee n r educed t he p r opeller can b e r e v er s ed and as t ern r e v olut ions buil t u p a s th e speed th r ou gh th e w a t er declines.

171. A t ypical R udde r C y cling man e u v er f or a ship p r oceeding wi t h 16 knot s w a s carri e d o u t as f ol l o w s: In i t i a l speed 16 k n ots. ( F ul l ahe a d ) Ha r d o v er t o p o rt 2 ° a n d, r educing speed t o ( Half ahea d ) A f t er tur n in g 4 ° t o p o r t , ha r d o v er the w heel t o sta r b o a r d side a n d r educe t o ( Sl o w ahe a d ) W h en t he s h ip h a v e passe d th e origi nal co u rse ha r d o v er t o p ort R educe t o ( Dead Sl o w ah e a d ) Fina l l y w hen coming bac k to th e origin al co u rse ha r d o v er t o sta r b o a r d an d e ng i nes ( F u l l as t er n ). S T O P ENGIN E . The t r ac k r each of thi s mane u v er is r edu c ed t o less tha n half t he c r as h s t op.

172. An c h o ri n g in e m e r g e n c y . A v essel is a p p r oa c hing a ch a nne l in r educ e d visibili t y , spe e d 5 knot s. T h e of f ice r of the w a t ch r e c e i v es a VHF co mmunic a ti o n th at the channel h a s be c ome bloc k ed b y a co l lisio n at th e ma i n ent r anc e . Wha t w ould be a r ec o mmen d ed course of action w hen the v essel w a s 1 mil e f r om th e obstruc t ed channel, with a flood tid e of ap p r o xima t e l y 4 knot s runn i n g as t ern? 1 . As sumin g th e v essel t o h a v e a ri g h t - hand fi x ed p r o pelle r , pu t th e rudder ha r d a- sta r b o a r d and s t op main e n gine s. The v essel w ould r esp o n d b y tu r nin g t o sta r b o a r d. The ancho r p a rty sho u l d stand b y f or w a r d t o le t go sta r b o a r d anc h o r .

173. Let g o sta r bo a r d ancho r . F ul l as t ern o n main engines t o r educe he a d r each. Letti n g g o the anc h or w ould ch e c k th e hea d w a y of t he v essel and act t o snub th e v essel r ound. S t op main engine s . F ul l a h e ad on main engines, with rud d er ha r d t o sta r b o a r d . Eas e and ch e ck th e c abl e as w ei g ht c o mes on th e an c h o r . Onc e th e v essel has s t op p e d o v er th e g r ou n d, g o half ah e ad on main engines, all o win g th e v essel t o come up t o w a r ds t he anc h or and s o r eli e v e th e s t r ain on th e cabl e. He a v e a w a y on t he cable and bring th e anc h or hom e. Cl e a r th e a r ea and i n v esti g a t e a sa f e a ncho r ag e or al t ernat i v e p ort until ch a nne l obstruction is cle a r e d .

174. S t opp i n g t e st S to p p i n g te st sho ul d b e p e r fo r m e d f r o m t h e test s p e e d wi t h maxim u m as t e r n p o we r . As i n d ic a te d in fi gu r e, t h e shi p ’ s t r a c k a n d h e a din g a f te r a s t er n o r de r a r e p l otte d v ersu s t i m e. C AP T R A JIV K V IG • Hea d r e a c h an d l ateral d e viatio n a r e p r e sen t ed in t er ms o f th e numbe r o f s h ip le ngths. Th e t i me l ag b etw e e n issuin g t h e a s te r n o r d e r a n d t h e m o m e nt wh e n t h e pr o p e l l e r s to p s a n d r e v e rse s s h o u l d b e m e as u r e d. S to p p ing t e st

175. T e s t spee d : C AP T R A JIV K V IG V T = C B x V D V T : t e s t s p ee d VD : d e s i g n s pe e d C B : b l o ck c o e ff i c i en t I M O s t a n d a r d: T r a c k re a c h < 1 5 L QU E S TI O N : I MO C R IT ER I A F O R S T OP P I NG D I S T A N C E I N C R A S H S T O P

176. R U D D E R C Y C L ING Q UE S TI ON : F A C T O R S W H I C H A FF E C T E F F I C IE N T R U D D E R C Y C L I N G: S P E E D , AR E A O F R UD D E R , R U D D E R F O RCE, S I D E FOR CE, D R A F T/ D E P T H RE L A TI ON S H IP C AP T R A JIV K V IG

177. C o m p a ris on o f d iff e r e n t s t o p p i n g t e chn i q u es QU E S TI O N : W h a t i s t h e mo s t e f f ec t i v e w ay o f a c h i ev i n g m i n i mu m h e ad r e a c h f o r s t opp i n g a s h ip C AP T R A JIV K V IG

178. Ty p e o f t ug c o-o p e r a t i n g w i t h a s h i p , w h e r e t h e m ai n d i f f e re n c e r e s u l t s f r o m t h e l o c a ti o n o f t u g’ s p ro pu l s i o n a nd t o w i n g p oi n t . T h e c h oi c e i s b e t w ee n c o n v e n t io n a l s i n g l e o r t w i n - s c r ew t u g s v e ry of te n fi t t e d w i t h n o z zl e s a nd t r a cto r ty p e t u g s. Th e A SD ( a z im u t h st e r n dr i v e ) t u g s a r e t h e c o m p ro m i s e l i nk i n g s o m e o f t he b e n efit s of c o n v en t io n a l a nd t r a c to r t u g s ty p e . QU E S T I O N : W H A T AR E T H E DI FF E REN T T Y P E S O F T U G S I N U S E ? C AP T R A JIV K V IG

179. D an g e r s r e l a t e d to s h i p -t u g co o p e r a t i o n W h e n as s i s t i n g a s h i p, t u g s o p e r a t e i n h e r clos e p r ox i m i t y i n d i s t u r b e d w a t e r p r e s su re r e gio n s su r r o u nd i n g a s h i p ’ s h u ll . T h i s i s t h e so u r c e of i n t e r a c t i o n p h en o m e n o n, e s p e c i al l y d a n g e r ou s f o r r e l a t i v e l y s m a l l t u g s w h e n co m p a r i n g w i t h t h e s i ze o f a s s i s t e d ships. C on s e c u t i v e p o s i t i o n s o f a t u g w h e n ap p r o a c h i n g a s h i p t o b e a ss i s t e d a re s h o wn i n f i g . . W h e n t h e t u g a pp r o ac h e s t h e a f t p a r t o f t h e s h i p ( po s i t i o n 1 ) , a n i n c r e as e o f he r sp e e d m a y o cc ur d u e t h e i n c o min g f l o w velo c i t y. In t h e c l o s e p r o x i m i t y o f sh i p ’ s h u ll , a l o w p r es s u r e s t a r t s t o m o v e t h e t u g t o w a r d s t h e h ul l . F or s h i p s in b al l ast co n d i t io n o r f or s h i p s h av i n g p a r t i c ular ove r h an gin g s t e r n, t h e t u g c a n ea s il y c o me t o p os i t i o n 2, w h i c h c r e a t e s d a n g e r of d a m a ge s t o t h e t ug ’ s hu l l an d su p e r s t r u c t u r e. Q U E ST IO N : I D E N T IF Y DA N G E RS T O T U G S I N P R O X IMI TY OF SHI P HUL L S; W H A T IS GI R T I N G •

180. • C AP T R A JIV K V IG P ro ceed i n g f u rt her a l ong t h e hu l l ( p o s i t i on 3 ) , t he tu g i s und e r i m po rt ant s uc t i on f o r ce o r i en t ed t o w a r ds t he s h ip’s h u l l and o ut w a r d t u r n i ng mo m e n t d u e to t u g bo w - cu s h i o n. O n ce s uck e d a l on g s i de it i s v e ry d i ff i cu lt t o g e t o f f a ga i n a n d t o con t i n u e t he w a y . T u g i n p o s i t i o n 4 e n t e rs t h e h i gh - p r e ss u r e a r e a. A r i s i n g ou t w a rd t u r n i ng m oment m u s t be elimi n a t ed by a pp r op r i a t e use of r udd e r a nd en g i ne. W h e n a rr i v i ng t o p o s i t i o n 5 c l o s e to t h e bo w , ve r y s tr ong “out f o r c e ” a c t i n g on t he st e rn t r i es t o br i ng t he t ug t o po s i t i on 6 b r oad s i d e und e r t he bow w i t h r i s k of c a p s i z i n g. I mm e d i a t e ac t i on o f r u dder and u s e of a v a il a b l e po w er ( f u l l a s t e r n) c a n co rr ect t he p o s i t i on. T r ac t o r s t y pe t u gs a r e l ess v u l n e ra b l e i n s uch a s it u a t i on. • • • • •

181. T h e ma in s ourc e o f dange r fo r a t u g w he n as s i st i n g a s h ip is s h i p ’s to o h i g h s p e e d . C l as s i ca l tu g acc i den t s (so - ca ll e d “ g i r t i ng ”) a r e pre s ente d in nex t th r e e fi gu r e s . I n fi g ., a t u g w ork i n g o n a li n e is ass i st i n g a s h ip mak i n g a tu r n t o s t arboar d (posit i o n 1) . Sh ip is s udden ly acce l e r at i n g fo r examp le t o im pr o v e tu r n i n g ab ili t i e s in o r de r t o rea li s e t h e tu r n cor r e c t l y . Th e spee d afte r f ew moment s b e c o me s to o h i g h an d t h e consecu t i v e tu g po s i t i on s a r e mor e an d mo r e a f t w i t h h i g h tens i o n in t h e t o w li n e ( p os iti on s 2 an d 3 ) . Th e danger of capsizin g is t he n r ea l. T h e abo v e - desc r i b e d s i tua t i o n is l e s s dangerou s f o r t r a c to r t ug s becaus e t h e ir to w i n g po i n t li e s a t th e aft . So - ca ll e d “ go b rope ” fo r convent i o n a l t ug s ca n im p r ov e muc h th e s i tua t i o n b y s h i f t i n g th e to w i n g p o i n t mor e t o th e s t ern , bu t o n han d it limi t s th e manoeuvr a b i l i t y o f th e tow i n g t u g. C AP T R A JIV K V IG 

182. C AP T R A JIV K V IG

183. C AP T R A JIV K V IG

184. C AP T R A JIV K V IG

185. • • C AP T R A JIV K V IG S o m e o t he r d a n g er s a f f e c ti n g f re q ue n t l y t u g ’s s af e t y a r e l i st e d b e l ow : B ul b o u s b o w s a r e n ot v i s i b le w h e n t h ey a r e under wa t e r a n d be ca u s e of t h e i r imp o r t a n t d im e n s io n s t h e s t er n of t h e t u g m ay t o u c h t h e b o w w h e n p as s i n g or t a k i n g a t ow l i n e . S h o r t to w l i ne s ca n a l s o c r e a t e s i m il a r d a ng e r f o r t u g s. T h i s s it u a tion i s e s peci a l l y d a n g er o u s i n t h e ca s e of e x c e ss i v e fo r wa r d s p ee d of s h ip s to b e a s s i s t e d . A n i ne x p er ien ce d s h ip’ s c re w m a y n o t b e a b le to re l ea s e t u g’ s towli n e w h e n n ee d ed. A f t er s l a c k i n g o ff t h e to w li n e b y a t ug , w h e n s h ip’ s s p ee d i n c r e a se s, t h e t en s i on s i m u l t a ne o u s l y i n c r e a ses i n t h e to w l i n e dr a g g e d t h r o u g h t h e wa t e r. T h e re l e asi n g of t h e t owl i n e be c o m es ver y di ff i c u l t, i f n ot im p os sib l e. • • • • • • • D A NG E R S A SSO C I A T E D WIT H T U G OP E R ATION

186. • C AP T R A JIV K V IG W he n th e bo lla r d p u l l o f a ssisti n g t u gs i s n ot su ff i c ien t t o co u nt e r ac t all e xt e r n a l f o rc e s a cti n g o n a shi p ( u n de r e s ti m a t i o n of win d f orc e, c u rr en t vel o cit y incr e a s e s ), tu g s c an be jam m e d b e t wee n t h e shi p an d th e b e r th a s t h e r e s ult of d ri f ti n g sh ip’ s m o t i o n. W he n p a ssi n g o r t a ki n g a t o wline, t h e sh ip’ s s pee d a n d he a di n g m us t be c o n st a nt . A n y ch an ge i n va lu e s of th e a b o v e pa r a me t e r s c r e a t e s a d di tio nal d a n g e r t o th e t u g . I f s u c h a sit u a tio n will o c c u r , th e a ssisti n g t u g m us t be immedia t e ly i n f or me d t o a nti c i p a t e e x pe c t e d ma n o e u v r e s . • • • • • •

187. SHIP D E A D I N WA T E R P L A C E M E NT OF T U G S P i v o t p oi n t a t m i d sh i p. T w o t u g s p u ll i n g or push i n g s i d e w a y s. Sh i p i s s h i ft i n g t o o n e s i d e w i t h o u t s w i n g i f b ot h t u gs d e v e l op e qu a l pu l li n g or push i n g fo r c e s a nd l e v e r s a re t h e s a me . C AP T R A JIV K V IG 3 2

188. S H IP MA K I N G H E ADWA Y P iv ot p oi nt sh i f t s fo r w a r d. S t e r n t u g wo r k i ng o n l a r g e l e v er i s mo r e e f f e ct i v e. Sh i p h a s a t e nd e n c y t o s w i n g t o p o r t . Q U E S T I O N: W H I CH T UG I S M O R E E F F E C T I VE I . G O I N G AHEA D II ) M O V I N G A S TER N C AP T R A JIV K V IG 3 3

189. P i v o t po i n t s hi f t s a f t . St e r n t u g w o r k i n g o n s m a ll L e v e r ( l e s s eff e c t i v e ) B o w t u g w or k i n g o n l a r g e L e v e r S hi p h a s a t e n de n c y t o sw i n g t o st a r b o a r d S h i p ma k i n g s t er n w ay C AP T R A JIV K V IG 3 4

190. M oo r in g L in es 2 1 3 4 6 5 B o w Lin e S t e r n L i n e S p r ing Li ne s A f t e r B ow S pri ng F or wa r d B o w S prin g A f t e r Q u a r t e r S prin g F or wa r d Q u a r t e r S prin g Sh i p h a n d li n g: Gr o u n d Ta c kl e , M o o r i n g L i n e s

191. M oo r in g L in es L i n e s • 1 - 6 Li n e s 1 a n d 6 a r e t h i c k e r t h a n o t h e r s Moo r i ng p r o ce d u r e f a k e o u t l i n e s s a fe ty b ri e f h e a v i n g l i n e s Sh i p h a n d li n g: Gr o u n d Ta c kl e , M o o r i n g L i n e s

192. M oo r in g L in es T er m s : H e a vi n g L i n e Ta tt l e t a l e F e n d e rs C a p s t an ( p. 1 88 Se a m a nsh i p ) R a t G u a r d s ( p. 1 7 5 S e am a n s h i p) Sh i p h a n d li n g: Gr o u n d Ta c kl e , M o o r i n g L i n e s

193. D e c k an d P i e r F it t in g s Sh i p h a n d li n g: Gr o u n d Ta c kl e

194. M oo r in g L in es 2 1 3 4 6 5 B o w Lin e S t e r n L i n e S p r ing Li ne s A f t e r B ow S pri ng F or wa r d B o w S prin g A f t e r Q u a r t e r S prin g F or wa r d Q u a r t e r S prin g Sh i p h a n d li n g: Gr o u n d Ta c kl e , M o o r i n g L i n e s

195. M oo r in g L in es L i n e s • 1 - 6 Li n e s 1 a n d 6 a r e t h i c k e r t h a n o t h e r s Moo r i ng p r o ce d u r e f a k e o u t l i n e s s a fe ty b ri e f h e a v i n g l i n e s Sh i p h a n d li n g: Gr o u n d Ta c kl e , M o o r i n g L i n e s

196. M oo r in g L in es T er m s : H e a vi n g L i n e Ta tt l e t a l e F e n d e rs C a p s t an ( p. 1 88 Se a m a nsh i p ) R a t G u a r d s ( p. 1 7 5 S e am a n s h i p) Sh i p h a n d li n g: Gr o u n d Ta c kl e , M o o r i n g L i n e s

197. S t a nd b y l i n e s Ta k e i n t he s l a c k Ta k e a s tr a i n H e a v e a r o u nd A v ast h e a v i ng H o l d C h e c k D o ub l e up S i ng l e up Ta k e i n S l a c k E a s e Ta k e t o t h e c ap s t a i n Gr o u n d Ta c kl e , M o o r i n g L i n e s Se q u e n c e : Command s : Sh i p h a n d li n g:

198. S a f e ty B att l e d re ss S n a p b a c k z on e Tu g s Pi l o t s l a d d e r Sh i p h a n d li n g: Gr o u n d Ta c kl e , M o o r i n g L i n e s

199. D e c k an d P i e r F it t in g s Sh i p h a n d li n g: Gr o u n d Ta c kl e

200. A n ch o rs Most c om m o n an c ho r S t a n d ar d N a v y S t o c k l e s s Most s h i p s ha v e t w o D ee p w a t e r a n c h o r - 1 4 s h o t s o f c h a in N o r m al a n c h o r - 12 sho t s o f ch a in S h o t - 15 f at h om s ( 90 f ee t) Sh i p h a n d li n g: Gr o u n d Ta c kl e , A n c h o rs

201. S c o p e o f C hai n 15 f a t h o m s 30 f a t h o m s 45 f a t h o m s 60 f a t h o m s Sh i p h a n d li n g: Gr o u n d Ta c kl e , A n c h o r i n g

202. A n c h o r in g Ap p r o a c h S t a n d b y L e t G o t he An c ho r R e p o rts P . 1 9 4 ( Se am a n s h i p ) An c ho r w atc h Sh i p h a n d li n g: Gr o u n d Ta c kl e , A n c h o r i n g

203. C o n ce r ns: W a t c h t h e ste r n / p i e r W a t c h f o r o the r s hi p s W i n d s / C u r r e n t s S e t on o r s e t o ff p ie r? Usi ng m oori n g l in e s and t ug s a s n e c e s s a r y t o c o nt r o l b o w / ste r n Sh i p h a n d li n g: G e t ti n g U n d e rw a y, Mo o r i n g

204. G e t ti n g U n d e rw a y, Mo o r i n g The I d e al Ap p r o a c h Ap p r o a c h on a c on v er g i n g c ou r se 10 t o 20 d e g r e e s f r om t h e h e a d i ng o f ou r b e rt h. Wh e n p a r a l l e l , s w i ng t he r u d d e r op p o s i t e t h e p i e r , and s t o p t h e s h i p. S t o p h e ad w ay b y b a c k i ng ou t b o a r d e ng i n e . “ Wa lk ” t he s h i p i n b y t e n s i on i ng li n e 1; “t w i s t ” t he s t e r n w i t h t he e ng i n e s . Sh i p h a n d li n g:

205. L e ss t h an I d e a l C on d iti on s B e ing S e t O n: S t op p a r a l l e l t o t h e pi e r , wit h 1 / 2 a b e a m w id t h o f op e n w a t e r b e t w ee n y o u a n d t h e pi e r . Al lo w t h e c u r r e n t t o push y o u o n t o t h e pi e r . B e ing S e t O ff : M a k e y o u r a pp r o a c h at a l ar g e r a n gl e t o t h e p i e r at a c o n sid e r a b l e s p e e d. B e c a r e fu l n o t t o p a rt y o u r b o w l i n e . Sh i p h a n d li n g: G e t ti n g U n d e rw a y, Mo o r i n g

206. E as i e r t h a n an c ho r i ng B u o y h e ld s e cu r e l y b y s e v e r al a n c h o r s. Ch a n c e o f d r ag g i n g r e d u c e d. T w o m e t h od s O r d i n a ry T r ol l e y Sh i p h a n d li n g: G e t ti n g U n d e rw a y, Mo o r i n g R e qu i r e s: M W B / R H IB w i t h b o at c r e w Y o u r s h i p A bu o y

207. C o nnin g O ff i c e r Dr i ve s t h e s h i p ’ s h e a d i ng and s p e e d t h r ough s t a n d a r d c omman d s ( o r d er s ) to t he h e l m and l e e h e l m H e l m - c on tr o l s t h e r u d d e r L e e h e l m - c on tr o l s t he p r op e l l e r s Sh i p h a n d li n g: S t a n d a r d C o mm a n d s

208. B as i c F o r ma t C o nn i n g O f f i c e r C om ma n d V e r b a t im R e p e a t b a c k ( C ar r i es o u t c o m m a n d ) R e po rt A c k n o w l e dg e s R e po rt He lm / L ee h e lm Sh i p h a n d li n g: S t a n d a r d C o mm a n d s

209. S t a n d a r d C o mm a n d s H E L M C O N SO L E Sh i p h a n d li n g:

210. Sh i p h a n d li n g: S t a n d a r d C o mm a n d s E NG I N E O R D ER TE L E G R A PH

211. I n v e s ti g a t i o n of E n v i r o n m e nt a l C o n d it i o n s ( h ar b o u r c o nd iti o n s ) H ar b o u r c o n d i t i o n s m u s t b e i n v e s t i g a t e d e a c h t i me a p ort i s e nt e r e d , n ot o n l y j u s t t h e fi r s t t i m e. F or li n e r s e r v i c e s , c o n d i t i o n s m u s t a l so b e i n v e s ti g a t e d a n d v er i f i e d a t a p p r o p r i a t e i n t e r v a l s as w e ll . S u c h i n v e s t i g a t i o n re q u i r es t h e c o ll e c t i o n of as m u c h d a t a as p o s s i b l e a n d v er if y i n g i t w i t h t h e l o c a l a g e n t . R e c e n tl y i t h as b ee n p o s s i b l e t o fi n d i n f o rm a t i o n o u t v i a t h e I n t e r n e t . H o w e v e r , ma n y v e ss e l s d o n ot h a v e an I n t er n e t c o n n e c t i o n , a n d i t i s t h e r e f o r e d e s i r a b l e t h a t a s h o r e t e am c o ll e c t s t h e r e l e v a n t d a t a a n d pro v i d es i t t o t h e v e s s e l .

212. ̑ I n v e s t i g a ti o n of G eo g r a p h i c a l C o n d i t i o n s a n d C o n d i t i o n s As s o c i a t e d w i t h H ar b o u r F a c ili t i es I n v e s t i g a ti o n of t h e N a v i g a t i o n E n v i r o n m e n t ( e . g . b u o y s , fi s h i n g v e s s e l s , fi s h i n g r e e f s , s h i p p i n g m o v e m e n t s ) I n v e s t i g a ti o n of t h e So c i a l E n v i r o n m e n t ( l o c a l r e g u l a t i o n s a n d n a v i g a t i o n r es t r i c t i o n s ) I n v e s t i g a ti o n of t h e N a t u r a l E n v i r o n m e n t ( e . g . w i n d , t i d e s , v i s i b i l it y , w a ve d i r e c ti o n ) T i d al In f o r m a t i o n t h r o u g h t h e In t ernet

213. E x am p l e of I n v e s t i g a t i o n of G eo g r a p h i c a l C o n d i t i o n s ( 1) M a x i m u m P e rm i s s i b l e D r a f t a n d U n d er K ee l C l e a r a n c e (U K C ) Ma x i m u m p e rm i ss i b l e d r a f t a n d U n d e r K e e l C l ea r a n ce ( U K C) a r e i m p or t a n t i n f o rm a t i o n i n ma k i n g d e c i s i o n s o n sa f e e n t ry of th e v e s s e l t o h ar b o u r . As s h o w n b e l o w , U K C i s a v a l u e i nd i c a ti n g th e m a r g i n b e tw e e n t h e s e a b o tt o m a n d t h e b o tt o m of t h e hu ll . F or e x am p l e, i f t h e w a t e r d e p t h a n d d r a f t a r e t h e s ame (U K C = ) , th e r e i s a p o s s i b i l it y t h a t th e v e s s e l m a y r u n a g r o u n d , a n d e nt ry t o h ar b o u r i s t h ere f o r e u n s a f e.

214. ̓ = R e l a t i o n s h i p B e t w ee n Ma x i m u m P e rm i s s i b l e D r a f t a n d U K C = T h e r e l a t i o n s h i p b e t w ee n m a x i m u m p e rm i s s i b l e d r a f t a n d U n d er K ee l C l e a r a n c e i s as s h o w n b y t h e f o ll o w i n g c a l c u l a t i o n . T h e m a x i m u m p e rm i s s i b l e d r a f t m u s t c o n s i d er e r r o r s a n d a s a f e t y f a c t o r t o g e t h er w it h t h e v ar i a b l es i n t h e c a l c u l a t i o n . I t i s a l so n e c e s s ary t o i n v e s t i g a t e t h e m a x i m u m p e r m i s s i b l e d r a f t f o r e a c h h a r b o u r ( or e a c h b er t h ) t o d e t e rm i n e p r o b l e m s .

215. M o s t h ar b o ur s s e t g u i d e li n e s f or U K C , a n d ma n y h ar b o ur s t h r o u g h o u t t h e w or l d m a n a g e U K C t o g e t h er w i t h d a t a o n w e a t h e r a n d s e a c o n di t i o ns t o e n s ur e a ma r g i n f or n a v i g a t i o n . ma n y h ar b o u r s e m p l o y f i x e d U K C w h i c h i s a p r o p or t i o n of t h e d r a f t , or a s et v a l u e i n m e t e r s . T h e E ur o p e an M ar i t i me P il o t s ’ A s s o c i a t i o n a n d t h e Ja p a n e se h ar b o u r t e c h n i c a l c r i t er i a e m p l oy t h e f o ll o w i n g g u i d e li n e s . ̔

216. O n c h a r t s, th e a l l o w a b l e li m i t f o r e r r o r in w a t er d ep t h a t t he i n t e r n a t i o n al d ep t h d at u m i s as f o l l o w s . W a t er d ep t h t o 2 m W a t er d ep t h t o 1 00 m W a t er d ep t h t o 1 00 m o r m o r e : U p t o 0.3 m : U p t o 1.0 m : 1 % o f w a t er d ep t h T he a ct u al w a t er d ep t h is t h e d ep t h on t h e c h a r t , p l u s o r m i nu s t h e t i d e l e v e l . T h e t i d e l e v e l i s o b t ai ne d f r o m t h e t i d e t a b l e . Si n c e t h is t i d e l e v e l is a p r e d i c t e d v al u e w h i c h c an be c al c u l a t e d f r o m a f i x e d d a t um, i t m u s t be c o n s i de r e d t h a t t h e a c t u al t i d e l e v e l m a y d i f f e r . I f t h e d i u rn al i n eq u al i t y a n d a b n o rm al w e a t h er c o n d i t io n s e t c . a r e i g n o r ed , th e acc u r a c y o f th e tid e t a bl e i s w i t hi n . 3 m of t h e a c t u al v al u e . ̕ = W a t e r D e p t h a n d T i d e l e v e l =

217. = V e s s e l ’ s S i n k a g e W h il e U n d e r w a y = W he n a v e ss e l b e g i n s mo v i n g t h e d is t r i b u t i on o f w a t er p r e s s u r e a r o un d i t c h a n g e s, a n d t he h u ll l o w e r s s l i g h t l y in t h e w a t e r . W he n n a v i g a t i n g in h a r b o u r s, t h e r e f o r e, t h e a m o u nt o f t h i s s i n k a g e o f t he v e ss e l in t h e w a t er m u s t be a d d e d t o t h e d r a f t w h i l e a t b er t h . T h is a m o unt b e c o me s g r e a t er as t he w a t er b e c o me s s h al l o w e r , a n d as s p ee d i n c r e a s e s, as s h o w n in t h e f o ll o w i ng g r a p h . L a r g e v e s s e ls a r e o pe r a t e d a t l ow s p ee d ( S / B s p eed ) in h a r b o u r s, a n d i t is t h e r e f o r e a p p r o p r i a t e t o e st i m a t e t h e s i n k a g e of t he v e s s e l as . 1 – . 2 % o f th e l e n g t h o f th e v e sse l. It is al s o n e c e s s a ry t o c o n s i d er s i n k a g e of t h e v e s s e l d u e t o r o ll i n g , p i t c h i n g a n d y a w i n g of t h e v e s s e l w i t h w i n d a n d w a v e s , a n d s w e l l . ̍ ̌

218. = E x am p l e C a l c u l a ti o n t o D e c i d e W h e th er or Not t o E nt er H ar b o u r = L O A = 2 00 m, d r a f t = 1 2.00 m M a x i m u m d r a ft of v e s s e l : D r a f t a t de p a r t u r e ( o r e x p e c t e d d r a f t a t a rr i v al) + a mo unt of s i n k a g e o f v e s s e l ( . 2 % of L O A ) 1 2 m + 20 m x 0.2 % ( 0.4 m ) = 1 2 . 4 m S a f e t y f a c t o r f o r w a t er d ep t h on c h a r t : 0.6 m ( w a t er d ep t h er r o r + t i d e l e v e l er r o r ) U K C : 1 – 2 % o f m a x i m u m d r a f t (de p e n d i n g on s ai l i n g a r e a ) , 1 5 % in c al c u l a t i on = 12.4 m x 1 5 % = 1.8 6 m M i n i m u m R e qu i r e d W a t er d ep t h = 1 2.40 m + 0.6 m + 1.86 m = 1 4 . 8 6 m ̍ ̍

219. ̍ ̎ ( 2) T u r n i n g B a s i n s W h e n e n t e r i n g a n d l e a v i n g m o s t h ar b o u r s , t h e v e ss e l w ill u s e it s o w n p ow e r , or a u x i l i a ry f a c ili t i es s u c h as t u g s or b o w t h r u s t er s , f or t u r n i n g . T h e h ar b o u r d e s i g n c r i t er i a g u i d e l i n es s p e c if y as s t a nd a r d a c i r c l e o f a d i ame t e r t hre e t i m e s t h e l e n g t h o f t h e ve ss e l w h e n t u r n i n g u n d er it s o w n p owe r , a n d t w i c e t h e l e n g t h w h e n t u r n i n g w i t h t h e a s s i s t a n c e of t u gs . M a n y h ar b o ur s d o n ot p r o v i d e s u f fi c i e n t a re a a s s h o w n i n t h e f o ll o w i n g d i a g r am. I n s u c h c a s e s , i t i s n e c e s s ary t o i n v e s t i g a t e t h e r e l e v a n t p o i n t s s u f fi c i e n t l y i n a d v a n c e ( v er if y i n g t h e n u m b er of t u g s r e q u i r e d , a n d d e t er m i n i n g t h e pr o c e d u r e f or t u r n i n g t h e v e s s e l . , e t c. )

220. ( 1) Ma x i m u m S i z e of A c c e p t a b l e V e s s e l a t P i er = D e s i g n C r i t e r i a f or H ar b o u r F a c iliti e s = T e c h n i c a l c r i t er i a f or h ar b o u r f a c ili t i es a c c o r d i n g t o J a p a n e s e m i n i s t er i a l o rd i n a n c es a r e a s f o ll ow s . V er i f y t h a t s u f fi c i e n t p i er l e n g t h i s a v a il a b l e b a s e d o n t h e l e n g t h of th e v e ss e l . T h e same c o n s i d e r a t i o n s a p p l y i n o t h er c o u n t r i e s . E x am p l e of I n v e s t i g a t i o n of P ort F a c ili t i es ̍ ̏

221. S t r e n g t h of Moor i n g B i t t s I t i s a l s o n e c e s s ary t o v er if y t h a t t h e m oor i n g b i t t s o n t h e p i er a r e a b l e t o w i t h s t a n d m oor i n g of t h e v e s s e l . S t r e n g t h of m oor i n g b i t t s i n a c c o r d a n c e w i t h J a p a n e se h ar b o u r t e c h n i c a l d e s i g n s t a n d a r d s a r e as f o ll o w s . ̍ ̐

222. Fe n d e r s F e n d e r s a r e a l so an i m p or t a n t i t e m of e q u i p m e n t f or sa f e m oor i n g of t h e v e s s e l . P ar t i c u l a r l y w h e n a s we ll e n t er s t h e h ar b o u r , i n s uff i c i e n t f e n d er s m a y r e s u l t i n d ama g e t o th e p i er a n d t o t h e h u ll of t h e v e s s e l . I f d ama g e d f e n d e r s a r e d i s c o v e re d a f t er e nt er i n g h ar b o u r , t h e y s h o u l d b e p h o t o g r a p h e d t o g u a r d a g a i n s t c l a i m s l a t er o n . ̍ ̑

223. T u g s T u g s a r e a n i m p or t a n t m e a n s of a ss i s t a n c e wh e n m a n e u v er i n g wh i l e e nt er i n g a n d l e a v i n g h ar b o u r . V e r if y i n g t h e nu m b e r a n d p o w er of t u g s i s an i m p or t a n t p art of t h e i n v e s ti g a t i o n of h ar b o u r c o n d i t i o n s . = P o w er a n d N u m b er of T u g s = Si z e a n d loa d i n g c o nd i t i on of t he v e s s e l C o n d i t io n s of m ain e n g i ne s , r ud de r s, a n d a n c h o r s of t h e v e ss e l W e a t h er a n d s e a c o nd i t i o n s (w i n d d i r e c t i o n , w i n d f o r c e, d i r e ct i o n a n d s p ee d of t i d al f l o w , w a v e s ) M e t h o d o f a p p r oa c h i n g a n d l e a v i ng t he p i er ( m o o r i ng t o w a r d t h e d i r e ct i o n of a r r i v al a n d d ep a r t u r e ) W a t er d ep t h i n t he a r e a ( c o n s i der e f f e c t s o f s h a l l ow w a t er ) A v ai l a b i l i t y o f t hr u s t e r s A r e a a v a i la b l e f o r m a ne u v e r i n g ̍ ̒

224. G u i d e li n es a r e c o m m o n l y s e t f or t h e n u m b er of t u g s r e q u i re d a t e a c h h a r b o u r . Us e th i s i n f o rm a t i o n f or r e f e re n c e. W h e n n o g u i d e li n es h a v e b e e n s e t , u se th e f o ll o w i n g e q u a t i o n t o d e t er m i n e th e n e c e ssa r y p o w er i n c o n j un c ti o n w it h t h e d e a d w e i g h t of th e v e s s e l . ̍ ̓

225. I t i s p o ss i b l e t o r e d u c e t h e n u m b er of tu g s i f t h e y a r e fi t t e d w i t h t h r u s t er s . W h i l e b o w th r u s t e r s o p e r a t e o n l y i n t h e t r a n s v er se d i re c ti o n , tu g s h a v e a s i g n i f i c a n t d i f f er e n c e i n t h a t t h e y a ll o w t o w i n g a n d p u s h i n g a t an a n g l e. I t i s i m p or t a n t t o i n c r e ase th e n u m b er of tu g s u s e d w h e n e n t e r i n g or l e a v i n g h ar b o u r w i t h o u t h e s i t a t i o n i n b ad wea t h er a n d s e a c o n d i t i o n s . B ow t h r u s t er T ug ( t o w i n g a n d p u s h i ng a t an a n g l e ) ̍ ̔

226. V e ss e l M a n e u v e r a b il i t y A p p ro x i m a t e l y 7 % of i n c i d e nt s of d a m a g e t o h ar b o u r f a c il i ti e s i n v o l v e d a m a g e t o p i e r s a n d f e n d e r s , h o w e v e r m o s t a r e d u e t o m i s t a k e s i n o p e r a t i o n of th e v e ss e l . S u c h m i s t a k es i n c o nf i n e d h ar b o u r s w i t h li m i t e d a r e a a v a il a b l e f or ma n e u v e r i n g a r e d u e t o t h e f o ll o w i n g ; I n a b ili t y t o a cc u r a t e l y d e t er m i n e t h e e f f e c t s of e x t e r n a l f o r c es s u c h as w i n d a n d ti d e s . M i s t a k es i n s p ee d c o n t r o l a n d t u r n i n g of t h e v e s s e l w h i l e u s i n g e n g i n es a n d t u g s . T h e s h i p n a v i g a t or g r a d u a ll y r e d u c es s p e e d i n a c c o r d a n c e w i t h th e d i s t a n c e re ma i n i n g , a n d i s r e q u i r e d t o a d j u s t s p e e d a n d t u rn t h e v e s s e l w h il e c o n s i d er i n g i t s t y p e, s i z e, l o a d i n g c o n d i t i o n , i n er t i a , ma n e u v e r a b ili t y , a n d t h e e f f e c t s of e x t er n a l f o r c e s . ̍ ̕

227. E f f e c t s o f E x t er n al F o r c e s (w i n d ) ᶃ S t r ai g h t a h e ad if n o e x t er n al f o r c es a r e a c t i n g in w i nd l e s s c o nd i t io n s . C / W Ќ / W B : W B Wi n d G ᶄ W h en th e w i n d is a t 4 5 ˃ t o s t ar b oa r d , th e v e s s e l is p r e s s e d t o l ee w a r d . T h e p oi n t a t w h i c h t h e w i n d a c t s (C ) is a h ead of th e v e s s e l ’ s c e n t e r of g ra v i t y (G) , a n d a tu r n i n g m om e n t ( N ( V α ) ) a c t s t o t u rn th e v e ss el in th e l ee w a r d d i r e c t io n . ᶅ W h en th e v e ss el b e g i n s d ri f t i n g ( d ia g o n all y ) l ee w a r d , w a t er : W Ќ E W a t e r R e s i s t. D i re c t i o n of S h i p M o v e m e n t r e s i s t a n c e is g e n e r a t e d on t h e lee s i d e of th e b o w . T h e p oi n t ( E) a t w h i c h th is f o r c e a c t s is a h e ad of th e p oi n t a t w h i c h t h e w i n d p r e s s u r e a c t s (C) , a n d a tu r n i n g m om e n t ( N (V β ) ) a c t s t o t u rn th e v e s s e l in th e w i ndw a r d d i r e c t io n . β : W М / W М ᶆ T h e v e ss el t u r n s und er t h e t u r n i n g m om e n t of t h e w i n d or w a t e r re s i s t a n c e , w h i c h e v er is th e g r e a t e r . Si n c e w a t e r r e s i s t a n c e is n orm a l l y m u c h g r e a t er t h a n air r e s i s t a n c e , the v e s s e l b e g i ns to tu r n w i nd w a r d. ( N ( V β ) > N ( V α ) ) ᶇ T h e r udd er a c t s a g ai n s t t h e t u r n i n g mo m e n t , i . e . th e v e s s e l is c o nt r olled w i t h th e m ome n t N ( V σ ) g e n era t ed b y th e r udd er a n g le ( σ) . ᶈ Fi n all y , w i t h t u r n i n g mo m e n t of th e w i nd , w a t er r e s i s t a n c e, a n d r udd er in e qu ili b ri u m, th e v e s s e l m ai n t ai n s a c o u r s e a t t h e a n g le β ( le e w a y ) t o t h e r i g h t a h e a d , a n d p r o c e e d s w i t h d ri f t i n g l ee w a r d . = T r a n s v e r s e M oveme nt a n d T u rn i n g U nd er W i n d P r e ss u r e W h il e U n de r w a y = ̎ ̌

228. ̎ ̍ T he p oi nt (C ) a t w h i c h t he w i n d a ct s a p p r oa c h e s t h e v e s s e l ’ s c en t er of g r a v i t y ( G) t h e c l o s er t h e r e l a t i v e w i n d is t o t h e t r a n s v e r s e a x i s o f t he v e ss e l. A t 9 ˃ ( a b e a m ) i t a c t s al mo s t en t i r e l y on t h e v e s s e l ’ s c en t er of g r a v i t y . A s a r e s u l t , t he t u r n i ng m o me nt N ( V α ) a ct i n g in t h e l e e w a r d d i r e c t i on is r e du c e d ( t u r n ) , a n d t h e f o r c e Y ( V α ) a ct i n g on t h e v e s s e l in t h e l e e w a r d d i r e ct ion i n c r e a s e s ( d r i f t ) , a n d t he d ia go n al a n g l e i n c r e a s e s, i n c r e a s i n g t h e t u rn i n g m o me nt N ( V β ) d ue t o w a t er r e s is t a n c e . F u r t herm o r e, w h e n t h e r e l a t i v e w i n d mo v e s f r om t h e t r a n s v e r s e t o t h e r e a r w a r d d i r e ct i o n , t he p o i nt (C ) a t wh i c h t h e w i n d a ct s mov e s f r om t he v e s s e l ’ s of g r a v i t y t o w a r d s t he s t ern , t h e t ur n i n g mome nt N ( V α ) r o u n d s u p t h e b o w , a n d a ct s in t h e s a me d i r e ct i o n as t h e w a t er r e s is t a n c e .

229. ̎ ̎ T he c o u r s e c an b e m ai n t ai ne d if t he mome nt d er i v e d f r o m t h e w i n d a n d w a t er r e s is t a n c e c an b e c o n t r ol l e d w i t h t he ru dd e r . I f s u c h c o n t r o l is n o t p o s s i b l e, an i n c r e a s e i n t he t u rn i n g m o me nt d u e t o w a t er r e s i s t a n c e i n c r e a s e s , a n d th e c o u r s e c a n n o l o n g e r b e m a i n t a i n e d . T h is g r a p h s h o w s t h e r at io of w i n d s p ee d ( V a) t o s pee d o f t h e v e ss e l ( V s ) on t h e v e r t ic al a x i s, a n d t h e r e l a t i v e w i n d a n g l e on t h e h o r i z o n t al a x i s, a n d i nd ica t e s t h e r e g i o n s i n wh i c h t h e c o u r s e c an a n d c a nn o t b e m ai n t a i n e d w i t h a ru dd er a n g l e of 3 ˃ . I f t h e r at io of w i n d s p ee d t o v e ss e l s p ee d e x c ee d s 3.7, a r e g ion o cc u r s in w h ic h t h e c o u r s e c a n n o t be m a i n t ai n e d d ue t o t h e r e l a t i v e w i n d a n g l e . A t v e s s e l s pee d s of 6 – 8 k n o t s ( 3. 1 – 4 . 1 m / s e c ) i n s i d e t he h a r b o u r , a w i n d s p ee d of 1 1 – 1 5 m / s ec r e s u l t s i n a r at io of w i n d s p ee d t o v e ss e l s p ee d of 3.7, a n d t h e c o u r s e m a y n o t b e a b l e t o b e m ai n t ai ne d in t h e s e c o n d i t io n s d epe nd i n g o n t he d i r e c t i on o f t h e r e l a t i v e w i n d .

230. ̎ ̏ I n t h e f o l l o w i n g g r a p h , ru dd er a n g l e i s s h o w n o n t he v e r t ic al a x is , a n d t he r e g io n s in w h i c h t he c o u r s e c an a n d c a nn o t b e m ai n t ai ne d f o r e a c h r at io of w i n d s pee d t o v e s s e l s p ee d . W h e n t h e r a t io o f w i n d s pee d t o v e s s e l s p ee d ( V a / V s ) r e a c h e s 4, de p e n d i n g on t h e a n g l e o f t he r e l a t i v e w i n d , a r e g i o n in w h i c h t he c o u r s e c a nn o t be m ai n t a i n e d o cc u r s, d e s p i t e a r u d d er a n g l e of 3 ˃ .

231. ̎ ̐ I t i s i m p or t a n t t o ma n e u v er t h e v e s s e l w h il e c o n s i d er i n g t h e r o u nd i n g u p a n g l e l e e w a y ( β) w h e n n a v i g a t i n g i n a c h a n n e l w it h o u t t h e as s i s t a n c e of t u g s u n d er w i n d pr e s s ur e. In s u c h c a s e s , w i n d d i r e c t i o n a n d s p ee d , a n d v e s s e l s p ee d , m u s t b e c o n s i d e r e d , a n d an i n v e s t i g a t i o n c o n d u c t e d t o d e t e rm i n e w h et h e r or n ot ma n e u v e r i n g i s p oss i b l e i n t h e r e gi o n i n w h i ch t h e c o ur s e c a n b e m a in t a i n e d . T h e m a x i m u m a ll o w a b l e w i n d s p ee d f or e nt er i n g a n d l e a v i n g th e h ar b o u r i s v ery o f t e n s e t , h owe v er hu ll s h a p e e t c . s h o u l d b e c o n s i d e r e d t o g e t h er w it h t h e c r i t e r i a e s t a b li s h e d f o r t h e h ar b o u r i n q u e s t i o n .

232. L e e w a y o f 3 ˃ t o s t a rb oa r d t o e n s u r e p a ss a g e u n d er c en t er of b r i d g e . (I n c h e o n P o r t ) M o d e r n r a d a r w i t h a d v a n c e d t e c hn o lo g y d i s p l a y s g e n e r a l l y i n c o r p o r a t e s G P S i n f o rm at io n . I f t h is f u n ct ion is u s e d s k i l l f u ll y t h e l e e w a y a n g l e a n d d i r e ct i o n of dr i ft c an be u n d e r s t ood i n nu me r i c al t erm s . T h i s i n f o rm at ion i s e f f e c t i v e i n m a n e u v er i ng t h e v e s s e l . ̎ ̑

233. T u r n i n g t h e V e s s e l u s i n g 1 ( o n e) T u g B o a t ( F r e e of E x t e r n a l F o r c e) W he n t ur n i n g w i t h o ne t u g pu s h i n g a t t he s t e r n ( o r b o w ) , t h e c en t er of t h e t ur n is t h e p i v o t p oi nt ( P ) , r at h er t h an t he c en t er of g r a v i t y ( G ) . T ur n i n g t h e v e ss e l on t h e s p o t in a c i r c l e o f r a d i u s 1 / 2 L ( L b e i ng t h e v e s s e l l e n g t h ) is t h e r e f o r e n o t p o s s i b l e . T he r a d i u s of a r e a r e qu i r e d f o r t u rn i n g c an be f o un d w i t h t h e f o ll o w i ng eq u a t i o n . T ur n i n g r a d i u s ( R ) = G P + 1 / 2 L C P G 1 / 2 L G C G P L : T u r n i ng r a d i u s o f m o me nt of i ner t ia a r o un d v e r t ic al a x i s t h r o u g h c en t er o f g r a v i t y ( G ) ˺ 0.3 5 L P : P i v o t p oi n t , c en t er o f r o t at ion w h e n t u r n i ng v e ss e l G : C en t er o f g r a v i t y C : P o i nt a t w h i c h t ug a c t s o n v e s s e l ̎ ̒ ː T u r n i ng t he v e s s e l

234. G П ʹ ̎ ̡ 1 m / s ec Si m u l at o r (C o n t ai ner ) ̎ ̓ T u rn i n g w i t h in a c i r c l e of d i a me t er 1 L u s i n g 2 t u g s u n d er Wi n d E f f e c t e x t er n al F o r c e A s i m u l a t i on w as ru n o f t ur n i n g a c o n t ai n er v e s s e l o f 24 6 m in l e n g t h s u b j e c t t o w i n d s of 1 m / s ec a t 4 5 ˃ t o s t a rb oa r d a t t he b e g i n n i ng o f t h e t u rn , u s i n g tw o t u g s . T h e t u g s w e r e u s e d s o l e l y f o r t u rn i n g , a n d n o a d j u s t me nt w as m a de f o r d r i f t . W h il e de p e n dent on h u ll s h a pe a n d v e ss e l t y pe, a w i n d s p ee d of 1 m / s ec i s t he l i m i t , e v e n if a 2 L ci r cl e is a v a i la b l e f o r t ur n i n g t h i s v e ss e l. A la r g er a r e a is r e q u i r e d f o r t u rn i n g a t w i n d s p eed s in e x c e s s of 1 m / s e c . - P B N - Q Q N # S F E U I N % F Q U I N % S B G U N % J T Q , 5 5 S J N N ( Q P TJ U J P O 8 J O E 1S P K F D U ' S P O U ᶷ ʣ 4 J E F ʢ ᶷ ʣ

235. S p e e d C o n t r ol I n c i d e n t s of f a i li n g t o c o n t r o l a s h i p ’ s s p e e d w h il e e n t er i n g h ar b o u r , w i t h t h e v e s s e l c o n s e q u e nt l y c o lli d i n g w i t h t h e p i er c a u s i n g m a j o r d ama g e t o t h e p i e r , s h o r e c r a n e s , a n d t h e v e s s e l it s e l f , n e v er c e as e. S h i p s d i f f er f r o m m o t or v e h i c l e s i n t h a t t h e y a r e n o t f it t e d w i t h a b r a k i n g m e c h a n i sm t o r e d u c e s p ee d . C o n t r o l of s p ee d m u s t t h e r e f o r e r e l y o n c o nt r o lli n g t h e s p e e d of t h e ma i n e n g i n e, re v e r s i n g t h e ma i n e n g i n e, or t h e as s i s t a n c e of a tu g . In o r d er t o e n s u r e t h a t t h e v e s s e l s t o p s pr e c i s e l y a t t h e s c h e d u l e d p o i nt , t h e s h i p n a v i g a t or i s r e q u i r e d t o c o n s i d er it s t y p e, s i z e, l o a d i n g c o n d i t i o n , i n e r ti a, a n d m a n e u v e r a b ilit y , a n d t h e e f f e c t s of e x t er n a l f o r c es e t c . w h e n a d j u s ti n g s p ee d . ̎ ̔

236. ̎ ̕ T h e se f a c t o r s a r e o b v i o u s l y n ot f o rma ll y c a l c u l a t e d w h il e t h e v e s s e l i s a p p r o a c h i n g t h e p i e r , a n d l a c k of c o m m u n i c a t i o n b e tw e e n t h e p il ot a n d c a p t a i n i s a c a u s e of i n c i d e nt s , as i s i n s uff i c i e n t a d v i c e f r o m th e c a p t a i n . B o t h t h e c a p t a i n a n d p il ot a r e r e q u i re d t o h a v e a q u a n ti t a t i v e, r a t h er t h an an i n t u i t i ve e x c h a n g e of i n f o rm a t i o n , b as e d o n e x p e r i e n c e, u n d er s t a n d i n g of t h e s t o p p i n g d i s t a n c e a n d t h e ti m e r e q u i r e d t o s t o p .

237. B as i c s of S t o p p i n g D i s t a n c e, V e s s e l W e i g h t , a n d A cc e l e r a t i o n H u ll s h a p e a n d r e s i s t a n c e m u s t b e c o n s i d e r e d w h e n d e t e rm i n i n g d e t a il s s u c h as s t o p p i n g d i s t a n c e a n d t h e t i me r e q u i re d t o s t o p , h owe v er a p p ro x i m a t e v a l u es c an b e d e r i v e d w i t h th e f o ll o w i n g e q u a ti o n b a s e d o n t h e p r i n c i p l e of c o n s e r v a t i o n of e n er g y . ̏ ̌

238. ̏ ̍ : A p p a r e n t d i s p l a c e m e n t ( d i s p l a c e m e n t + a d d i t i o n a l ma s s *) ( t o n s ) V o : I n i t i a l s p e e d (m / s e c ) : F i n a l s p ee d ( m / s e c ) F : F o r c es a c t i n g ( t u g t h r u s t a n d r e v e r se e n g i n e t h r u s t ) ( t o n s ) T : E l a p s e d t i me ( s e c o n d s ) S : F o r w a r d m o v e m e n t ( m) Α : A cc e l e r a t i o n a p p li e d t o v e s s e l (m / s e c 2 ) * A d d i ti o n a l m a s s W h e n a cc e l e r a t i n g a n d d e c e l e r a t i n g t h e v e s s e l , t h e v e s s e l i t s e l f m o v e s , w h il e a t t h e s ame t i m e, t h e wa t er i n t h e v i c i n it y a l s o m o v es as a r e s u l t of t h i s m o v e m e nt . P owe r i s th e re f o r e n ot o n l y r e q u i r e d t o m o ve t h e v e s s e l , b u t t o m o ve a p a rt of t h e wa t er i n t h e v i c i n i t y . T h i s i s , i n e f f e c t , t h e same as m o v i n g a v e s s e l of i n c r e as e d mas s . T h i s i n c r e a s e d mas s i s re f e r r e d t o as ‘ a d d i t i o n a l ma s s ’ .

239. S p e e d R e d u c t i o n P l an f or V e ss e l A p p r o a c h i n g P i er i n D i r e c t i o n of Arr i v a l ( e x am p l e) W h e n a p pr o a c h i n g p a r a ll e l t o t h e p i er i n t h e d i re c ti o n of arr i v a l i t i s n e c e s s ary t o d e t er m i n e i n a d v a n c e w h e n t o s t o p th e e n g i n e, a n d t o u n d e r s t a n d g u i d e li n e s f or e v a l u a ti n g w h e t h e r or n ot s p e e d th r o u g h th e p r i ma r y w a y p o i nt s i s e x c e s s i v e w h il e a p p r o a c h i n g t h e b er t h . F or e x am p l e, wh i l e m o v i n g f o r w a r d a t d e ad s l o w a h e ad as s h o w n i n th e f o ll o w i n g i m a g e, w h e n s t o pp i n g t h e e n g i n e w i t h s i m u l t a n e o u s b r a k i n g a p p li e d b y a s t e rn t u g , a n d w i t h a d i s t a n c e t o t h e s t o p p o s i t i o n of 4L a n d 1 L , i t i s n e c e s sa r y t o d e t e rm i n e b e f o r e h a n d t h e s p e e d a t w h i c h i t i s p o s s i b l e t o s t o p a t t h e s c h e d u l e d p o i n t . W h i l e i n c o r p o r a t i n g a s a f e t y m a r g i n i n t h e d i s t a n c e t o t h e b er t h n o t e d a b o v e, i t i s a l so n e e d e d t o r e d u c e s p e e d b y i n c r e as i n g t h e b r a k i n g e f f e c t of th e t u g or b y re v e r s i n g t h e e n g i n e i f t h e a p pr o a c h t o t h e b er t h i s a t a g r e a t er s p ee d .

240. In p r a c t i c e, r a t h er t h an m a n e u v er i n g t h e v e s s e l t o s t o p a t t h e s t o p p o i nt , b r a k i n g i s a p p li e d w h il e c o n t r o lli n g s p ee d so t h a t t h e v e ss e l s t o p s a t t h e t a r g e t a t t h e f r o n t of t h e b er t h w i t h o u t l o s i n g c o n t r o l . V e r i f y d i s p l a c e m e n t o f v e ss e l, p o w e r a t e n g i n e a st e r n , a n d po w e r o f t u g , v e r if y t h e d i st an ce a n d ti m e r e qu i r e d t o st o p d u r i n g m a ne u v e r i n g f o r a p p r o a c h , a n d m a n eu v e r t h e v e ss e l w it h a s a f e t y m a r g i n . ̏ ̏

241. R e f e r e n c e V a l u es f or R e d u c i n g S p e e d T h e s pr e a d s h e e t b e l o w p re s e n t s t h e e q u a t i o n i n ( 4 ) - 1 i n a f or ma t r e a d y f or d a t a e nt r y . E n t e r t h e n e c e ss a ry d a t a t o c a l c u l a t e a p p ro x i m a t e v a l u es f or s t o p p i n g d i s t a n c e a n d s t o p p i n g t i m e, a n d sa f e t y ma r g i n . I t i s i m p or t a n t t o r e c o g n i z e r e f e re n c e v a l u es f or t h e s t o p p i n g d i s t a n c e of t h e v e s s e l u s i n g s i m p l e s pr e a d s h e e t s . E a r l y b r a k i n g b y tu g or re v e r s i n g t h e e n g i n e i s n e c e ssa r y i f th e sa f e t y ma r g i n i s . 3 or l e ss . ̏ ̐

242. ̏ ̑ I n a d d i t i o n t o t h is s p r e a d s h e e t, i t is al s o e f f e c t i v e t o c o n s i d er t h e m a n eu v e r a b il i t y o f t he v e ss e l in p r ep a r i ng s p ee d r ed u ct ion g u i de li ne s in g r a p h i c f orm a t . T he g u i de li ne s s h o u ld b e p o s t e d o n t h e b r i d g e, w i t h c o p i e s k ept in st o r a g e . T he g u i de li ne s c an b e p r ov i de d t o t he p i lo t as r e f e r e n c e m a t er ial f o r i n f orm a t i on e x c h a n g e u p on b o a r d i n g t o a s s i s t in c o mm u n i c a t i o n .

243. U p t o 20 , 00 G T ( c o n v en t io n al me t h o d ) C o n v e nt i o n a l l y , t h e v e ss e l a p p r o a c h es a t an a n g l e o n a f a c e l i n e of t h e p i e r , t h e b o w li n e i s t a k e n , a n d th e s t ern i s p u s h e d t o t h e p i e r . T h i s m e t h o d i s s t ill u s e d w i t h v e s s e l s of u p t o 20,00 G T . H o w e v e r l a r g e r v e s s e l s g e n e r a ll y a p p r o a c h a n d p o s iti o n p a r a ll e l t o t h e p i er a t a d i s t a n c e of 1 . 5 – 2 t i m es t h e b e am, a n d a r e t h e n p u s h e d s i d e w a y s o n t o t h e p i er b y a t u g ( p a r a ll e l a ppr o a c h ) . L a r g e v e s s e ls e x c ee d i n g 2 ,0 G T ( p a r all e l a pp r oa c h ) C o n t r o l of B er t h i n g V e l o c i t y W h e n A p pr o a c h i n g t h e P i er ̏ ̒

244. ̏ ̓ = A d v a nt a g es a n d d i s a d v a n t a g e s of th e p a r a ll e l a p p r o a c h = [ A d v a nt a g e s ] W h i l e t h i s d e p e nd s o n t h e l a y o u t o f t h e p i e r , a m i s t a k e i n r e d u c i n g s p e e d d o e s n ot r e s u l t i n d ama g e t o t h e p i e r . W h e n t h e p i er i s of c o n s i d e r a b l e l e n g t h , a m i s t a k e i n s p e e d c o n t r o l s i m p l y r e s u l t s i n o v e rr u n n i n g t h e s c h e d u l e d s t o p p o s iti o n , a n d d oes n ot r e s u l t i n d a m a g e t o t h e p i e r . Wi t h t h e c o n v e n t i o n a l m e t h o d , c o n t a i n er s h i p s e t c . w it h l a r g e b o w fl a r e s s o m e ti m es d ama g e c r a n es e t c . o v e r h a n g i n g t h e p i e r . T h i s r i s k i s m u c h r e d u c e d w i t h t h e p a r a ll e l a p p r o a c h . T h e a t t it u d e of t h e v e ss e l i s m o r e e a s il y c o n t r o l l e d w i t h t h e p a r a ll e l a p p r o a c h , f a c il it a t i n g r e s p o n se t o r a p i d c h a n g es i n e x t er n a l f o r c e s . [ D i s a d v a n t a g e s ] An e x t r a 1 – 2 m i n u t es i s r e q u i r e d t o r e a c h t h e p i e r .

245. ( 5) B er t h i n g V e l o c i t y C o n t r o l T h e e n er g y of th e v e s s e l w h e n c o n t a c ti n g t h e p i er c an b e c a l c u l a t e d w i t h t h e f o ll o w i n g e q u a t i o n , a n d i s p r o p or t i o n a l t o t h e s q u a r e of th e s p e e d of c o nt a c t . E W’ G V C : C o n t a c t ene r g y ( t o n- m ) : W ( d i s p la c eme nt ( t o n s ) ʷ t r a n s v e r s e a dd i t i o n al m a s s c o eff i c i ent ( 1 - – 2.0 ) : A cc e l e r a t i o n du e t o g r a v i t y ( m / s e c 2 ) : B e r t h i n g V e l o c i t y ( m / s e c ) : E ne r g y d i m i n u t i on c o e f f ic i ent d u e t o t ur n i n g e t c . ̏ ̔

246. C o n t a c t e n e r gy ( t - m) B e rt hi n g V e lo c i ty ( V c m / s e c ) Us i n g an a d d i t i o n a l mas s c o e ff i c i e n t of 1 . 8, a n d C of . 5 i n t h e a b o ve e q u a ti o n , a c o n t a i n er v e ss e l w i t h a d i s p l a c e m e n t of 50,0 t o n s a p p r o a c h i n g t h e p i er a t a s p e e d of 10 cm / s ec h a s a c o nt a c t e n er g y of a p p ro x i m a t e l y 2 3 t o n - m. T h i s i s e q u i v a l e n t t o a 1 t o n m o t or v e h i c l e c o lli d i n g w i t h a w a ll a t 8 k m /h . V e ss e l s g e n e r a l l y a p p r o a c h a t a m a x i m u m s p ee d of 10c m / s e c , w i t h l a r g e v e s s e l s a n d V L C C s a p p r o a c h i n g a t 5c m / s e c. T h e se s p ee d s a ll o w a b s or pt i o n of t h e e n e r g y of t h e v e s s e l w h e n c o n t a c t i n g t h e p i er f e n d er s , a n d pre v e n t d a m a g e t o t h e h u ll a n d t h e p i e r . ̏ ̕

247. P r e v e n t i n g D a m a g e t o H ar b o u r F a c ili t i e s G r asp Ex t e r n a l f o r c e s C o n t r o l t h e a t t i t u d e a n d s p e e d of t h e v e ss e l a p p r o p r i a t e l y w h il e ma n e u v e r i n g . I t i s n e c e s s ary f or t h e c a p t a i n t o p l an t h e pr o c e d ur e f or e n t r y a n d e x i t i n a d v a n c e. B r i d g e R e s ou r ce M a n a g e m e n t D u r i n g H ar b o u r E n t r y a n d E x i t S / B W h e n t h e p il ot b o a r d s t h e v e s s e l , pr e s e n t t h e p il ot c a r d , a n d e x p l a i n d r a f t , d i s p l a c e m e n t a n d o t h er p o i n t s of s p e c i a l n o t e. O ff i c e r s s t a t i o n e d a t t h e b o w a n d s t e rn re p ort r e p ea t e d l y o n m o ve m e n t of t h e t u g s. ̐ ̌

248. B r i d g e R e s o u r c e M a n a g e m e n t D u r i n g Arr i v i n g a n d a n d D e p ar t ur e S / B i n H a r b o u r C on s u lt w i t h t h e n a v i g a t o r o n t h e d a y p ri o r t o h ar b o u r e n t ry f o r a b r i e fin g on h a r b o u r e n tr y a n d e x i t p r oc e du r e s. W h en t h e p il o t b o a r d s t h e v e ss e l, p r e s e n t t h e p i l ot c a r d , a n d e x pl a i n d r a f t , d i s p l a c e m e n t a n d o th e r p o in t s of s p e c i a l n o t e . O b t ain i n f o rm a t i o n f r o m t h e p il o t o n w h er e t h e tu g i s t o b e t a k e n up , w h e t h er t h e p i e r is t o b e a pp r o a c h e d o n th e s hip ’ s p o r t or s t a r b o a r d s id e , a n d t h e nu m b e r of m o o r i n g l in e s e t c . t o b e u s e d . I f t h er e is t ime a v aila b l e, v e ri f y t h e re qu ir e m e n t s f o r m a n e u v e r i n g o f t h e v e ss el ( e . g . t u r n i n g po i n t ) . ̐ ̍

249. E n s u r e th a t t h e o f f i c e r on th e b r i d g e r e p o r t s e n g i n e s p ee d ( w h en e n g i n e s a r e op e ra t e d ) , a n d t h a t t h e h e l m s m a n r e p o r t s r udd e r s t a tu s as a p p r op r ia t e. W h en t h e e n g i n e i s s t o p p ed in t h e f i n a l s t a g e s o f a pp r o a c h i n g t h e p ie r , t h e o f f i c er m a y b e g in t i d y i n g u p t h e b ri d g e a n d h e / s h e ma y n e g l e c t t o r e p o rt t h e b er t h i n g v e l o c i t y o f t h e v e ss e l. I t i s i m po r t a n t t h a t t h e r e q u i r ed i n f o rm a t i o n ( e .g . a h ea d / a s t ern s p ee d , b e r t h i n g v e l o c i t y ) i s re po r t e d a p p r op r i a t ely u n t il an i n s t r u c t i o n is r e c ei v ed f r o m t h e c a p t ain t h a t it is n o l o n g er n e c e ss ar y . O f fi c e r s s t a t i o n e d a t th e b ow a n d s t e r n r e p o r t r e p e a t e d l y on m o v e m e n t of th e tu g s. I n n o n- E n g l i s h - s p ea k i n g r e g i on s i n p ar t i c u l a r , t h e p i l o t a n d c a p t ain o f t h e t u g f r e q u e n t ly c o n v e r s e in t h e l o c al la n g u a g e, a n d i n f o r m a t i o n o n m o v e me n t o f t h e t u g ma y no t r e a c h t h e c a p t a i n o f t h e v e ss e l. I t i s i m po r t a n t t h a t o f f i c e r s s t a t i o n ed a t t h e b o w a n d s t e rn r e p o rt c o n c i s e ly w h e t h er t h e t u g s a r e p u s h i n g o r p u l l i n g t h e v e ss e l, a n d i n w h i c h d i r e c t i o n e tc . ̐ ̎

250. M oo r i n g l in e s a r e s e t i n co n s u lt a t i on w it h th e p i l ot or Ma s t e r . E v en a f t er t h e l i n es a r e t ied o n t h e b i t t s , t h e y a r e g e n e r a lly l e f t un - t e n s i o n ed (w i t h n o s la c k ) . I t is i m p o r t a n t t o f o ll o w t h e i n s t r u c t i o n s o f t h e s h ip n a v i g a t o r w h en w i n d i n g in m o o ri n g li n es t o c o n t r o l t h e a t t i t u d e o f t h e v e ss el. I t i s al w a y s n e c e ss ary t o v e r i f y a n y d o ub t s . T h is a p p li e s n o t o n ly t h e c a pt a i n , b u t al s o t o t h e c r e w . T h e c a p t ain is r e s p o n s i b le f o r c r e a t i n g an a t m o s ph e r e in w h i c h t h is b e h a v i o r is e n c o u r a g e d . ̐ ̏

251. A s h i p ’ s a n c h o r d r a g s T he i m p a c t o f e x t er n al f o r c e s D r a g g i n g A n c h o r > T h e h o l d i n g p o w er o f t h e a n c h o r a n d c a b l e . M a s t e r s a n d d e c k o f f ic e r s s h o u ld be a w a r e o f h ow v a r i o u s p a r a m e t e r s , s u c h as t he s c o pe o f c a b l e in r e l at i o n t o t he d e p t h o f w at er a n d t h e e f f e c t s o f w i n d , w a v e a n d t i d a l f o r c es o n t h e v e sse l , c an in t u r n e x ert e x c e ss i v e f o r c e s o n t h e a n c h o r a n d c a b l e s y s t e m l e a d i ng t o b r e a k - o u t o f t h e a n c h o r f r o m t he g r o u n d a n d d r a g g i n g . T h e r e a s o n w h y an a n c h or d r a g s ̐ ̐

252. E m p i r i c al o r R u l e o f T h u m b M e t h o d s f o r A ss e ss i ng t h e M i n i m u m R e q u i r e d L e n g th o f An c h o r C h ain d : W a t er d ep t h ( m ) L : M i n i m u m R e q u i r e d L e n g t h of A n c h o r C h ai n( m ) J a p a n e s e p ub li c at i o n T h e o r y o f S h ip O p e r at i o n Fi ne w e at h er : R o u g h w e at h er: L = 3 d + 9 m L = 4 d + 1 4 5 m U n i t e d Ki n g d om pu b li c a ti o n T h e o ry o f S h ip O p e r at i o n L = 3 9 x ˽̳ m ̐ ̑

253. T r a d iti o n al m e a n s o f d e t e cti ng a d r a g g i ng a n c h o r ᶃ C h e c k i ng t h e s h i p ’ s p o s i t i o n , t o c o n f i rm w h e t h er i t is p la c e d o u t s i d e o f a t u r n i ng ci r cl e . ᶄ T h e b ow c a n n o t s t a n d a g ai n s t t h e w i n d . ᶅ T h e s h i p ’ s s i d e a g ai n s t t he w i n d h a s n ’t c h a n g e d . ᶆ C h e c k i ng t o s e e t h e r e is n o s la c k i n g o f c h ai n s j u s t b e f o r e a s h i p ’ s s i de a g ai n s t t h e w i n d t u r n s . ᶇ C h e c k i ng w h e t h er t h e r e a r e e x t r a o r d i n a ry v i b r at i o n s t h r o u g h t h e a n c h o r c h ai n s . ᶈ C h e c k i ng t h e c o u r s e r e c o r d er in c a s e i t d o e s n o t i n d i ca t e a “ f i g u r e - o f - e i g h t ” m o t i o n l o c u s . ̐ ̒

254. T h e a b o v e me t h o d s r em a i n w e l l - t r i e d b ut , o f c ou r s e , o n ly c o n f i r m t h a t t h e a n c h o r is d r a gg i n g . T h e y d o n o t p r e d i ct w h e n d r a gg i n g i s l i k e l y t o c o m me n c e . A cc o r d i ng t o o n e c u r r e n t s t u d y , an a n al y s is o f a n c h o r d r a gg i ng h as s h o w n t h a t t h e r e a r e tw o a ss o c i a t e d p h e n o m e n a , o r s t a g e s , t o t h e p r o c e s s w h i c h i n d i c at e t h a t d r a g g i n g m a y b e a b o u t t o o c c u r b e f o r e i t is d e t e c t e d by t h e m o r e u s u al m e t h o d s o u t l i n e d a b o v e . ̐ ̓

255. T h e F i r s t S t a g e : D r a gg i n g A n c h o r w i t h Y a w a n d S w a y Y a w a n d s w a y mo ti o n o f a v e ss e l w h e n lyi ng t o an a n c h o r is s o m e t i m e s r e f er r e d t o as “ h o r s i n g ” . A r e a [ A ] in t h e d ia g r a m s h o w s t h e s i t u a t i o n w h e r e t he s h ip is lyi ng a t a n c h o r a n d y a w i n g in a “ f i g u r e - o f- e i g h t ” mo ti o n . I t h as b ee n f o u n d t h a t as w i n d p r e ss u r e f o r c e b e g i n s t o e x c ee d t he a n c h o r ’ s h o l d i ng p o w e r , t he s h ip y a w s a n d is p r e ss e d t o l ee w a r d , as s h o w n by a r e a [ B ] in t h e d ia g r a m . I t is s u g g e s t e d t h a t , du r i ng t h is p er i o d , i t s h o u ld be r e la t i v e l y e a s y t o c o nt r ol t h e m a neu v e r a b i l i t y o f a sh i p i n su c h a s ta t e a n d t o w e i g h th e a n c ho r . ̐ ̔

256. T h e S e c on d S t a g e : An c ho r D r a gg i n g ca u s e d b y W i n d P r ess u r e W h e r e w i n d p r e s s u r e f o r c e g r a du all y b e c o m e s s t r o n g e r , o n e s i d e o f t h e s h ip t u r n s a g ai n s t t h e w i n d a n d is t h e n p r e ss e d a n d mo v e s t o l ee w a r d a t a c er t ain s p ee d , as s h o w n in a r e a [ C] in t h e d ia g r a m . I t is s u g g e s t e d t h a t , d u r i ng t h is s t a g e, i t is d i f f i c u l t t o w e i g h a n c h o r a n d , e v e n if p o s s i b l e, t h is t a k e s a c o n s i d e r a b l e a m o un t o f t i m e . I f w e i g h i ng t h e a n c h o r c a nn o t be a cc om p l i s h e d , t he s h ip l o s e s i t s m a n e u v e r a b ilit y . D r a gg i n g a n c ho r m a y n ot b e d e t e c t e d b y t h e T r a d i t i on a l M e t ho d s unt i l th e v e ssel h a s e nt e r e d t h e se c o n d s t a g e des c r i be d a b o v e , b y w h ic h t i m e i t m a y b e t o o la t e t o a vo i d a d a n g e r ous s i t u a t i o n f r o m d eve l o p i n g . ̐ ̕

257. E a r l y p r e d ic t i o n a n d d e t e ct i o n o f t h e d r a g g i n g o f an a n c h o r is al s o p o ss i b l e u s i ng t h e s h i p ’ s w a k e i n d i c a t o r s in t he E C D I S , R A D A R a n d G P S d i sp l a y s . T h e r e f o r e, c o u n t er m e a s u r e s f o r t he s a f e t y a r e r e q u i r e d t o be t a k e n as e a r li er as p o s s i b l e . E C D I S A R E A ʮ ̗ ʧ R A D A R A R E A ʮ ̗ ʧ G P S A R E A ʮ ̘ ʧ ̑ ̌

258. ː 3. 2 Wi n d P r e ss u r e F o r c e C a l c u l a t i o n H u g h es F or m u l a В : Wi n d di r e c t ion f r om b o w [d e g r e e ] ( R e l a ti v e W i n d D i r e c t i o n ) 7 B : H ea d w in d s p e ed [ m / s e c ] ρ : Air d e n s it y [ . 12 5 k g ɾ s e c 2 / m 4 ] : S h i p ’ s p r oje c t e d a r ea f r om b o w a b o v e wa t erli n e [ m 2 ] : S hip ’ s p r o je c t ed a r e a f r o m s i d e a b o v e wa t erli n e [ m 2 ] a : L e n g t h f r om b o w t o w in d p r e ss u r e c e nt e r [ m] ( P o i n t o f A c t ion ) R B : R e s ul t a n t w i n d p r e ss u r e f o r c e [ k g ] → d i v id e d b y 1 ,0 t o b e “ t o n ” ( T o t al W i n d For c e ) α : W i n d p r e ss u r e f o r c e a n g le[ d e g r ee ] ( A n g le o f A c t i o n ) C R a : W i n d p r e s s u r e f o r c e c o eff i c i en t . P a s s e n g er : 1.14 2 - 0.14 2 c o s 2 В 0.3 6 7 c o s 4 В - 0.13 3 c o s 6 В G e n e r al C a r g o : 1 . 3 2 5 - . 50 c o s 2 В - . 3 50 c o s 4 В - 0.17 5 c o s 6 В T a n k er & B u l k c a rr i er : 1.2 - 0.0 8 3 c o s2 В - 0.25 c o s 4 В - . 1 17 c o s 6 В R e s u l t a n t w i n d p r e s su r e f o r ce i s p r op o r t i o n a l t o t h e s q u a r e of w i n d s p e e d . 3 B ͇ Л ͇ $ 3 B Y 7 B Y " D P T В ʴ ̗ T J O В ʣ U P O ̑ ̍

259. ː 3. 3 H o l d i n g P o w er c r e a t e d b y A n c h or a n d A n c h or C h a i n S : C a t e n a r y l e n g t h a g ai n s t t h e e x t er n al f o r c e ( m ) Z : W a t er d e p t h + H a w s e p i p e h e i g h t f r o m s ea s u r f a c e ( m ) M : M i n i m u m R e q u i r ed C o n t a ct e d le n g t h o f t h e c h ain ( m) L : M i n i m u m R e q u i r ed L e n g t h o f A n c h o r C h ain ( m ) ( = S + M ) 5 Y : E xt e r n al f o r c e ( k g f ) H ( H o l d i n g P o w e r c r e a t e d b y An c ho r a n d An c ho r C h a i n) = H a + H c = λ a x W a ’ + λ c x W c ’ x M ̑ ̎

260. H : H o l d i ng p o w er c r e a t e d by A n c h o r a n d A n c h o r C h ain ( k g s ) H a : H o l d i ng p o w er by A n c h o r ( k g s ) Hc : H o l d i ng p o w er by A n c h o r C h a i n ( k g s ) ( R e s i s t a n c e of c a b l e ) W a : A n c h o r W e i g ht in A i r ( k g s ) W c : A n c h o r C h ain W e i g ht p er m in A i r ( k g s ) W a ’ : A n c h o r W e i g ht in W a t er ( k g s ) = . 8 7 x W a ( k g s ) W c ’ : A n c h o r C h ain W e i g ht p er m in W a t er ( k g s ) = . 8 7 x W c ( k g s ) M : M i n i m u m R e qu i r e d L e n g t h of A n c h o r C h ain ( m ) λ a : A n c h o r H o l d i ng F a ct o r λ c : A n c h o r C h ain H o l d i n g F a c t o r Е B " O D I P S ) P M E J O H ' B D U P S Е D " O D I P S $ I B J O ) P M E J O H ' BD U P S + * 4 " $ ̑ ̏ 5 Z Q F 4 B O E . V E % S B H HJ O H ̟ ̞ ̨ " $ ) P M E J O H % S BH H J O H ʙ 4 B O E . V E

261. C a l c u l a t i n g t h e C a t e n ary L e n g t h of an A n c h or C h a i n 5 Y 8 D ̨ ʹ ͈ 2 ʴ Z S : C a t en a r y l e n g t h a g a i n s t t h e e x t er n al f o r c e ( m ) Z : W a t er Dep t h + H a w s e p i p e h e i g ht f r o m s e a s ur f a c e ( m ) W c ’ : A n c h o r C h ain W e i g ht p er m i n W a t er ( k g s ) = . 8 7 x W c ( k g s ) T x : E x t ern al f o r c e ( k g f ) U n d er th e c o n d iti o n th a t L [M i n i m u m R e qu i r e d L e n g t h of A n c h or C h a i n ( S + l ) ] i s fi x e d a t a c e r t a i n l e v e l , i f T x [ Ex t e r n a l f o r ce (k g f ) ] i n c rea s e s, S [ C a te n a r y l e n gt h a g ai n s t t h e e x ter n a l f o r c e ( m) ] w i l l a l so i nc r e a s e . O n th e c o n t r a r y , h owe v e r , l [ M i n i m u m R e q u i re d C o n t a c t e d l e n g t h of t h e c h a i n ( m) ] d e c r e as es so t h a t H [ H o l d i n g p owe r c r e a t e d b y A n c h or a n d A n c h or C h a i n (k gs ) ] w i l l b e d i m i n i s h e d . ̑ ̐

262. ᶃ → ᶄ F r o m r i g h t t o l e f t . A n c h or c h a i n i s t i g h t c o n d iti o n ᶅ L e f t s i d e p o s iti o n . A n c h or c h a i n b e c o me re l a x e s . B i g g e s t I m p a c t F o r c e ᶆ ᶇ → ᶈ F r o m l e f t t o r i g h t . A n c h or c h a i n i s t i g h t c o n d iti o n ᶉ R i g h t s i d e p o s i ti o n . A n c h or c h a i n b e c o me re l a x e s . B i g g e s t I m p a c t F o r c e ᶊ In t h i s w a y , t h e s h i p ’ s c e n t e r of g r a v i t y i s m o v i n g i n a “ fi g ur e - o f - e i g h t ” p a tt ern as ill u s t r a t e d b y th e g re e n t r a c k i n t h e d i a g r am. ː 3. 5 H o r s i n g ( Y a w i n g a n d S w a y i n g ) M o t i o n a n d I m p a c t F o r c e ̑ ̑

263. ̑ S h i p ’ s o p e ra t i o n a l s a f et y m ea s ure s f or a n cho r ag e a n d t h e i r e f f e c t s C o u n t e r m e as u re s I n c re a s e d r a u g h t b y t a ki n g i n b a ll as t w a t e r E f f e c t i v e n e s s S h i p ’ s w e i g h t i s i n c r e a s e d so t h a t v e s s e l ’ s m o t i o n s (H o r s i n g ) a r e d e c re a s e d . T h e p o i n t of a c t i o n s h i f t s a f t e r w a r d a n d t e n d s t o d e c r e ase t h e h o r s i n g m o t i o n . I n c re a s e s a n c h or c h a i n h o l d i n g f a c t o r . E x t e n d e d c a t e n a r y l e n g t h a b s or b s m o r e e x t er n a l f o r c e o n a n c h o r . R e mar k s C o n s i d er s t a b ili t y i s s u e s . T r i m b y t h e h e ad C o n s i d e r s t a b ili t y i ss u e s . M a i n t a i n p r o p e ll er i mm er s i o n . V e e r m o r e a n c h or c a b l e C o n s i d e r t h a t w e i g h i n g a n c h or i s d i f fi c u l t i n r o u g h s e a c o n d i t i o n s a n d m o r e t i m e w i l l b e r e q u ire d t o w e i g h t h e a nc h o r .

264. C o u n t e r m e as u re s D r o p t h e o t h er a n c h or E f f e c t i v e n e s s C an r e d u c e y a w i n g a n d h o r s i n g m o t i o n b y h a l f , a n d r e d u c e f o r c e o n a n c h or b y 30 % ʙ 40 % . R e mar k s C o n s i d e r am o un t of s e c o n d c a b l e r e q u i r e d i s o n e a n d a h a l f t i m e s t h e d e pt h of wa t e r . C o n s i d e r t h e p o ss i bi l i t y of f o ul i n g t h e c a b l e s , p a r ti c u l ar l y w h e n p i t c h i n g h e a v il y . D a n g er of f o u li n g an a n c h or i f t h e v e s s e l i s t u r n e d u n d e r t h e i nf l u e n c e of w i n d a n d / or t i d e . F r o m t h e o u t s e t of a n c h or i n g , t o d e p l oy b o t h a n c h o r s R i d i n g t o tw o a n c h o r s i s sa i d t o i n c re a s e h o l d i n g p o w er a n d t o d e c r e ase h o r s i n g m o t i o n . ̑ ̕

265. C o u n t e r m e as u re s Us e o f b o w th r u s t e r s E f f e c t i v e n e s s B y s t e mm i n g th e w i n d , t h i s c a n e f f e c t i v e l y r e d u c e t h e h o r s i n g m o t i o n a n d e ase c a b l e t e n s i o n . I f t h e p ow er of t h e b o w t h r u s t er i s 80 % o f t h e w i n d f o r ce o n t h e b o w , i t i s sa i d t h a t w i dt h of o s c ill a t i n g m o t i o n a n d i m p a c t f o r c e a r e d i m i n i s h e d b y a b o u t 4 %. R e mar k s T h e po s s ib i l i t y t h a t e x t e n d e d use of t h e b o w t h r u s t er s m a y n ot b e p oss i b l e f or t e c h n i c a l rea s o ns. E n s u r e t h a t th e b o w t h r u s t er s a r e k e p t s u b m e r g e d w h e n t h e s h i p i s p i t c h i n g a n d r o lli n g . ̒ ̌

266. C o u n t e r m e as u re s Us e o f t h e m a i n e n g i n e i n c o m b i n a ti o n w i t h s t e er i n g E f f e c t i v e n e s s T h i s c an b e an e f f e c t i v e d e t e r r e n t t o t h e h o r s i n g m o ti o n a n d w ill r e li e v e t h e t e n s i o n o n t h e a n c h or a n d c a b l e s y s t e m. R e mar k s D o n ot a ll o w t h e v e ss e l t o p a y -o f f s u d d e n l y w h e n t h e t e n s i o n o n t h e a n c h or c a b l e h as b ee n e as e d a s a s u dd e n i n c r ea se i n t e n s i o n m a y brea k - o ut t h e a n c h o r . D o n ot a ll o w t h e v e s s e l t o o v e rr i d e t h e a n c h o r , p a r ti c u l ar l y i n s h a ll o w w a t e r w h e r e t h e v e ss e l c o u l d i m p a c t o n t h e a n c h or i f p i t c h i n g . ̒ ̍

267. ̒ ̎ =E x am p l e c a l c u l a t i o n o f t h e i n c r ea s e i n h o l d i n g p ow er w h en c a b l e i s v ee r ed = S h i p ’ s t y p e A n c h or W e i g h t i n A i r ( W a) : P C C l a d e n w i t h 6,00 u n i t s : 10 . 5 t o n ˰ 9 . 13 5t o n i n W a t er W a t er D e pt h + H a w s e p i p e h e i g h t f r o m s e a s u r f a c e ( y ) : 25 . m L e n g t h of o n e s h a c k l e of a n c h or c a b l e S h i p ’ s P r oje c t e d a r e a f r o m b o w a b o ve w a t e r li n e ( A) Wi n d pr e s s ur e f o r c e C o e f fi c i e n t ( C Ra ) : 27 . 5 m : 8 00 s q m : . 7 5 Ai r d e n s it y ( ρ ) : . 1 2 5 k g / s e c 2 / m 4 T h e a n c h or c a b l e i s a s s u m e d t o h a v e f or m e d a c a t e n a r y w i t h n o c a b l e l y i n g o n t h e g r o u nd . A n c h o r H o l d i n g F a c t o r ( λ a) : 7 . A n c h o r C h ain W e i g h t p e r m e t e r in Air ( W c ) : . 166 t o n / m ˰ . 14 4t o n i n W a t e r

268. A n c h or H o l d i n g P o w er = I m p a c t F o r c e ( e x t e r n a l f o r c e ) : 63 . 90 t o n f C a t e n a r y L e n g th ( S’) : 1 50 . 90 m ( 5 . 5 s h a ck l e s ) T h e c r iti c a l w i n d s p e e d c an b e c a l c u l a t e d f r o m t h e H u g h es F o rm u l a : 1 6 .9 m / s e c. T h e a v e r a g e w i n d s p e e d 11 . 3m / s e c ʙ 13 . 5m / s e c. T h e c r iti c a l w i n d s p e e d = A v e r a g e w i n d s p ee d x 1 . 2 5 ʙ 1 . 5 ˎ I m p a c t F o r c e ( e x t er n a l f o r c e) T h e Wi n d F o r c e f r o m a h e ad : 1 . 65 t o n f = Wi n d F o r c e f r o m a h e ad x 6 ̒ ̏

269. ̒ ̐ ( S i t u a t i o n a f t er o n e a d d i t i o n a l s h a ck l e ( 2 7 . 5 m) of c a b l e i s v e e r e d ) A f t er a fu r t h er s h a ck l e of c a b l e i s v e e r e d , t h e c r i t i c a l w i n d s p e e d w ill b e i n c r e a s e d . O n l y p art of th e l o n g er c a b l e s y s t e m w ill l a y a l o n g th e g ro u n d w i t h th e r e m a i n d er f o rm i n g p art of a n e w c a t e n a r y . Y Z 8 B Y ЕB 8 D Y ЕD Y M 8 D ̨ ʢ ̼ ʵ ̻ ʣ ʹ ͈ 2 Y S ’ : C a t e n a ry L e n g t h b e f o r e o n e s h a c k l e i s v ee r e d 1 5 0.90 m ( 5 . 5 s h a ck l e s ) M : C o n t a c t e d l en g t h o f t h e c h a i n ( laid ov er t h e b o t t om ) 2 3 . 6 m A d d i t io n al N e w C a t e n a ry 3.9 m : T h e ho l d i n g p o w e r c r e a te d b y t h e a nc h or a n d c a bl e s y s te m = 67 . 3 t o n

270. = 17 . 3 m / s e c . = 11 . 5 m / s ec ʙ 13 . 8 m / s e c . I n c o m p a r i s o n w i t h t h e av e r ag e w i n d s p ee d b e f o r e o n e s h a ck l e of c a b l e i s v e e r e d, t h e r e a r e i n c r e a s e s of . 2 m / s e c ʙ . 3 m / s e c t o t h e c r i t i c a l w i n d s p ee d. I m p o r ta n t l y f or t ho se o n t h e b ri d g e , t h e c r i t i c a l w i n d s p ee d i s n o t i n c r e a s e d a s m u ch a s m i g h t b e e x p e c t e d e v e n i f t h e a n c hor c a b l e i s v ee r e d c on s i d e r a b l y . a f u ll l e n g th o f c a b l e ( 12 s h ac k l e s ) is v ee r e d ) T h e a v e r a g e w i n d s p e e d = 13 . 1m / s e c ʙ 15 . 7m / s e c. ̒ ̑ T h e w i n d f o r c e f r o m a h e ad = 1 1 . 2 3 t o n f . T h e c r iti c a l w i n d s p e e d T h e a v e r a g e w i n d s p e e d I n c r e a s e o f 1 . 8 m / s e c ʙ 2 . 2m / se c

271. T h e C r i t i c a l W i n d S p ee d W h il e l o o k i ng i n t o v a r i o u s r e f e r e n c e b o o k s , t h e r e is n o c o n c r e t e i n d i c a t i o n . R e a s o n s T h e h o l d i n g p ow er of e a c h v e s s e l ’ s a n c h or i s d e p e n d e n t up o n t h e c o n d iti o n of t h e g r o u n d i n t h e i mm e d i a t e v i c i n it y . T h e a c t u a l h o l d i n g p o w er m a y n ot a l w a y s c o n f o r m t o t h e t h e o r e t i c a l v a l u e o b t a i n e d b y c a l c u l a t i o n . C o n t i n u i n g c h a n g es i n t h e d i r e c t i o n of t h e a n c h or c a b l e a n d t h e a n g l e of a c t i o n o n t h e m oor i n g s y s t e m . T h e r e s u l t i s t h a t t h e a n c h or c a b l e m a y b e s u b je c t e d t o s h o c k s t re s s es as t h e c a b l e s a g s a n d t h e n ti g h t e n s . T h e h o r s i n g m o ti o n m a y n ot b e c o n s t a n t a n d t h e m o t i o n m a y e v e n b e a cc e l e r a t e d . A f t er t a k i ng i n t o c o n s i d e r at i o n all t h e f ac t o r s s et o u t a b o v e t h e s a f e a n d p r u d e n t d e ci s i o n m a y w e ll b e n o t t o a n c h o r . ̒ ̒

272. E m e r g e n c y m e a s u r e s t a k e n a n d t h e i r e f f e c t i v e n e s s a f t er d r a gg i ng a n c h o r ᶃ V e e r i n g an A dd iti o n a l c a b l e a n d u se of th e s e c o n d a n c h or A d d i n g c a b l e t o th e fi r s t a n c h or i s n o t s ee n as an e f f e c t i ve m e a n s of s t o p p i n g a s h i p f r o m b e i n g pr e ss e d a n d d r i f ti n g t o l e ew a rd . ᶄ Us e of b o w t h r u s t er T h e m i n i m u m t h r u s t e r p ow er m u s t b e e q u a l t o th e w i n d f o r c e o n t h e b o w . ᶅ Us e o f t h e ma i n e n g i n e a n d s t eer i n g T h e r e q u i re d p o w er of t h e ma i n e n g i n e ̒ ̓ S t ee ri n g : H a r d Ov e r Wi n d s p ee d : E n g i n e O r d e r 20 m / s e c : Sl o w A h e ad 25 m / s e c : H alf A h e ad 30 m / s e c : F u ll A h e ad

273. D i ff i c u l t y i n m a i n t a i n i n g m a n e u ve r a b i l i t y I t s h o u ld b e r e m e m b e r e d t h a t w h e n t h e p r o p e ll er is w o r k i ng t h e e f f e c t o f t h e b ow t h r u s t er w ill be d e c r e a s e d by a b o u t 2 % p er 1 k n o t o f a h e ad s p ee d . I n o t h er w o r d s , a t a b o u t 5 k n o t s , t h e e f f e c t o f t he b ow t h r u s t er is n e g a t e d . L i m i t a t i o n o f m a n e u v er i n g by r u d d er N u m b e r s e nt e r e d i n th e v er t i c a l a x i s a r e w i n d s p e e d p e r s h i p ’ s s p e e d a n d t h e w i n d f o r c e a n g l e i s e n t er e d a l o n g t h e h o r i z o nt a l a x i s . T h e y e l l o w z on e s h o w s t h e a r e a un d e r t h e cu r v e i n w h i c h t h e ef f e ct of t h e r u d d e r i s l os t . ม ਑ ෆՄೳ Ҭ W i nd S p e e d / S h i p ' s S p e e d ૬ର ෩ ޲ ֯ ʢ ౓ ʣ 3 F M B U J W F 8 J O E E J S F D U J O E F H V O J U T ̥ ̘ ̘ ɺ I E I ਫ ਂ 8 B U F S % F Q U I ม ਑ Մ ೳ Ҭ ෩ ଎ / ધ ଎ ൺ U n a b l e M a n e u v e r i ng A r e a M a n e u v e r i n g A r e a ม ਑ ૢ ધ ͷݶք - J N J U B U J P O P G . B O F V W F S J O H C Z 3 V E E F S Wi n d s p e e d of 20 m / s e c , t h e s h i p ’ s s p ee d w o u l d h a v e t o b e m o r e th an 5 k n o t s ( 2.5 m / s e c) ̒ ̔

274. P r e p a ra t i o n f or s a f e a n c h o r a g e T h e f o ll o w i n g c o n s i d e r a t i o n s m u s t b e t a k e n i n t o a c c o u n t : T o s e l e c t a s h e lt er e d g oo d a n c h o r a g e La n d c o n fi g u r a t i o n T h e b o t t o m c o n fi g u r a t i o n H o l d i n g g r o u n d i n g c o n d i ti o n An a p pr o p r i a t e d e p t h S u ff i c i e n t r oo m S h e l t e r e d f r o m s u c h an e x t e r n a l f o r c e as w i n d a n d s e a D e g r e e of c o n g e s t i o n of o t h er s h i p s a t a n c h o r a g e T o pre v e n t an a cc i d e n t i n t h e e v e n t t h a t t h e a n c h or d r a g s K ee p a sa f e d i s t a n c e f r o m o t h er s h i p s K ee p a sa f e d i s t a n c e f r o m s h a ll o w s / o t h e r f a c ili t i es ̒ ̕

275. R e c e n t ly t h e r e h as b een an i n c r ea s e in t h e nu m b e r of a c c i d e n t s i n v ol v i n g a n c h or c a b les b e c o m i n g e n t a n g l e d or a n c h o r s a n d c a b les b ei n g lo s t . T h e s e a cc i d e n t s h a v e m o s t ly b e e n c a u s e d b y m i s t a k es t h a t w e r e m a d e du ri n g t h e o p e r a t ion of l e t t i n g g o t h e a n c h o r . I n p ar t i c u la r , mo s t a cc i d e n t s h a v e b e en c a u s ed b y n ot c o n t r olli n g th e r un n i n g - o u t s p eed of th e a n c h or c a b le, th a t i s , w i th o u t b r a k i n g w h e n t h e a n c h or is l e t g o. T e s t r e s u l t s s h ow th a t t h e s p eed of a n c h or f r ee f all r ea c h es 1 m / s ec a f t er 5 m w h e n an a n c h or is l e t g o w i th o u t b r a k i n g . T h a t is t o s a y , 12 s h a c k l e s ( = 3 30 m) c o u ld t o t ally r u n o u t in 33 s e c o nd s . A c c o r d i ng t o i n v e st i g a t i on r e s u l ts, al t h o u g h m o s t m a r i n e r s i n v o l v e d in a n c h o r - r e l a t e d a cc i den t s s t a t e d t h a t t he b r a k e d id n o t w o rk w e l l , t h o r o u g h i n v e s t i g at io n s on s i t e h a v e e s t a b l i s h e d t h a t a bent b r a k e s h a f t a n d / o r la c k of m ai n t e n a n c e w e r e t h e c a u s e . T h e c r e w w e r e u n a b l e t o p r o p e r l y a p p l y t h e b r a k e . T o e n s u r e s a f e a n c h o r i n g , t h e v eer i n g r a t e m u s t be l i m i t e d t o a b r a k e f o r c e of 5 t o 6 m / s e c . A n c h or O p e r at i o n ̓ ̌

276. ̓ ̍ I f t h e d ep t h a t an a n c h o r a g e e x c ee d s 20 m, t h e p o ss i b i li t y o f d a m a g e t o o r lo s s of t h e a n c h o r a n d i t s c a b l e be c ome s g r e a t er du e t o e x c e s s i v e r u n n i ng o ut s p ee d if t he a n c h o r i s al l o w e d t o f r ee f al l . T o a vo id t h i s h a z a r d , t h e a n c h o r s h o u ld b e l o w e r e d by w a l k i n g b a c k i n t o t h e w a t er u n t il t h e a n c h o r r e a c he s a b o ut 5 m a b o v e t h e b o tt o m . W he n l e t t i n g g o , t h e b r a k e s h o u l d b e a pp l i e d in o r der t o s l ow t h e v eer i ng r a t e un t i l t he l en g t h v ee r e d is a b o u t 2 m - 3 m m o r e t h an t h e w a t er d ep t h . T h is s h o u ld p r e v ent t h e c a b l e f r o m p i l i n g o n t o t h e a n c h o r . A f t er t h e a n c h o r t o u c h e s t h e b o tt o m, t h e s h i p ' s s t e r n w a y s h o u ld b e li m i t e d t o a b o u t 0.5 k - 1 k n o t in o r der t o a v oid i m p o s i n g e x c e s s i v e st r a i n o n t he c a b l e a n d al s o t o fu r t her a v oid p i li n g . T h e a i m is t o l a y t h e c a b l e a c r o s s t he g r o u n d in an o r d e r l y f a s h ion a n d w i t h o ut i m p o s i ng a n y e x c e s s i v e st r e s s on t h e s y s t em . (I d e a l l y , r e p e a t st r e t c h i n g , li t t l e by l i t t l e, e v ery t i me u n t il i t b e c o me s t a u t. )

277. An c h o r C a b l e V ee r in g R a t e ɾ S c o p e o f C a bl e T o B e P a i d O u t ɾ B r a k e F o r ce o f W i ndl a ss T he G r a p h o n t he n e x t p a g e s h o w s t he r e l at io n s h ip b e tw ee n b r a k e f o r c e, s c o p e of c a b l e a n d v eer i ng r a t e d e t erm i n e d d u r i n g t r i als on b oa r d a 2 3 0, 00 dwt V L C C w h e n a n c h o r a n d c a b l e a r e p a i d o u t u s i n g t h e b r a k e . D ur i ng t h e t r ial , t he c a b l e w as f i r s t r e l e a s e d w i t h h alf b r a k e a p p li ed . T he b r a k e w as a p p l i e d 3 s e c o n d s a f t er l e t t i n g g o t he a n c h o r a n d w as fu l l y a p p li e d a g ain a f t er a n o t h er 5 s e c o n d s in o r der t o st op v ee r i n g c o m p l e t e l y . A s c an b e s ee n , t h e l e n g t h of c a b l e v ee r e d t h is t i me is a b o u t 2 1 m . I f t h e a n c h o r is l et g o by f r ee f all a n d t h e v eer i n g r a t e e x c eed s 10 m / s e c , i t b e c o me s d i f f i c u l t t o a r r e s t t he c a b l e a n d t h e b r a k e l i n i ng m a y b e d a m a g e d . I f , h o we v e r , t h e v ee r i n g r a t e is l i m i t e d t o a b o u t 5 - 6 m / s ec by t h e t i me l y a p p l icat ion of h alf b r a k e, s u c h d a m a g e w ill be a v o i d e d . ̓ ̎

278. 3 F T V M U P G 7 - $ $ " O D I P S J O H E x a m p l e s of en t a n g li ng ̓ ̏

279. T e c h n i c a l m e a s ur es w h il e l y i n g a t a n c h or E x t e r n a l f o r c e s ass o c i a t e d w it h w i n d s p e e d s a n d d i r e c ti o n s w a v e h e i g h t a n d p er i o d F l o w d i r e c t i o n a n d v e l o c i t y S h i p ’ s t y p e , H u ll d i m e n s i o n s , d r a u g h t , t r i m U n d e r s t a n d i n g t h e h o l d i n g p o w er of t h e a n c h or s y s t e m Q u a n t i t a t i v e as s e s s m e n t of w i n d p r e s s ur e f o r c es M a n a g e m e n t of t h e ma i n p r o p u l s i o n s y s t e ms P r e d i c ti o n a n d ear l y d e t e c t i o n of d r a g g i n g a n c h or U n d e r s t a n d f u ll y t h e r e l a t i o n s h i p b e t w e e n h o l d i n g p ow er a n d e x t er n a l f o r c es T o d e t e c t d r a g g i n g a n c h or b y o b s e r v i n g t h e h o r s i n g m o ti o n T o u s e t r a c k d i s p l a y f u n c ti o n of E C D I S ɾ R A D A R ɾ G PS ː 3 . 1 2 T e c h n i c a l M e a s u r e s f o r A n c ho r i n g ̓ ̐

280. ࢀߟ ɿ ߴ଎ધ ͷ F u ll S p ee d ߤ૸Լ ʹ ͓ ͚ Δ ճ಄ӡಈ ͱ ੍ޚ T a k i ng i n t o a c c o unt T ur n i n g M o t i o n in t h e e v ent t h a t a h i g h s p ee d v e ss e l ( c o n t ai n er s h ip o r P C C e t c . ) is o p e r at i n g a t f u ll - loa de d c a p a c i t y a n d a t f u ll s p ee d . F ail u r e as a r e s u l t o f r a p i d t ur n i n g d u r i n g o p e r at ion a t h i g h s p ee d F o r e x a m p l e, t h e f o l l o w i n g p r o b l em s m a y o cc ur w h e n a c o n t a i n er s h ip o p e r at i n g a t 2 2 k n o t s s t ee r s i t s r u d d er t o f u ll ( h a r d -ov er) . I f t h e m a i n e n g i n e is i n ov er - load ( t o r qu e r ic h ) a n d a l s o in M O o p e r at ion mo d e, m ain en g i n e r p m d e c r e a s e s t o g e t h er w i t h t h e s o u n d i ng of t h e S l ow D o w n ala r m . O u t er h ee l i n c r e a s e s d u e t o c en t r i f u g al f o r c e . B e c a u s e G o M of a c o n t ai n er s h i p is b e t w ee n 1. 2 a n d 1. 8 m e t e r s a t f u ll l oa d , o u t er h ee l i n c r e a s e s d ue t o r a p id r o t at io n , w h i c h m a y c a u s e a d a n g e r o u s s i t u at io n . So as n o t t o c a u s e t he a b o v e f a i l u r e, i t is a r eq u i r eme nt t h a t t h e v e s s e l n a v i g a t e a t a r e s t r i c t e d r a t e - o f - t ur n s pee d a t 5 - 1 d e g r ee s per m i n u t e ( 1 5 d e g r ee s per m i n u t e a t m a x . ) . ̓ ̑ R e f . ɿ V e ss e l T u r n i n g M o t i o n a n d C o nt r o l f or H i g h S p e e d v e s s e l s u n d er F u ll S p e e d c o n d iti o n s

281. Turning in Ci r cles A case study of the distaster which started the first international convention The Turning Chara c teri s tics of the SS T it a nic T a ct i c al dia m ete r 9 0° T r an s f er F ina l Dia m ete r Advan c e

282. PR E S E NT A TION OV E RVI EW What d o w e al r ead y know abou t Ti t anic' s tu r ning abil i t y ? Some tu r ning basics Develop i ng the model Ti t anic' s tu r ning ci r cle 1 4 Ap r il 1 91 2 a t 11:4 PM ATS The class i c scena r io does not h old up A f ai l e d port - aroun d maneuver? Was there a "ha r d - a - starboard " call?

283. What D o We Alr e ad y Kn o w? Titanic turned a full circl e of 385 ft measure d dia m e t e r at 20. 5 knot s during her se a trials off B elfast Lough . 1 Fo r w a r d tra v e l for the hard turn w a s repor t e d a t 210 fe e t . 1 ,3 A hard-a- sta r board (left full rudder ) order a t 21. 5 knots result s in a headi n g chang e of t w o poi n ts (2 2. 5 degrees) a fter 3 7 seconds . 2 A hard-a- sta r board (left full rudder ) turn a t 2 2 knot s w ould resu l t in a fo r w ar d m o v e m en t of abou t 44 y ard s ( 132 f t ) for a heading chang e of 2 po i nts . 3 ,4 S m al l change s of spee d do n ot sign i fican t ly chang e the dia m e t e r of the turning circle , just the time it ta ke s to turn a certai n a m ount . 5 R efe r e n ces: Eat o n & H aas , T ita n ic - T ri u m p h a n d T r a g e d y , Ch . 4 , 2 n d E d . E d w a rd W il d i ng , B riti s h I nqu iry ( B I 25292). E d w a rd W il d i n g a t R ya n Vs. Ocea n ic Steam N av i g at i o n Co . E d w a rd W il d i n g a t t h e N Y L i m itat io n o f L i a b il i ty H ea ri ng s . M r . Ro c h e ( M ari n e E ng i n ee r ’ s A ss o ciati on ) B riti s h I nqu iry p . 77 .

284. S om e T u rning Bas i cs T urning Cir c le - A ship ’ s t u rning ci r cle is t h e path f ol l o w ed by the ship ’ s pi v ot point w hen m aking a 360 de g ree turn. A d v ance - A d v ance i s th e a m ou n t o f d ist ance run on th e or ig in a l course until th e sh i p ste ad ie s on th e new cou rse. A d v ance i s m easured f rom th e po in t w here th e ru d d e r i s f i r st p u t o v e r . T r ansfer - T ran s f er i s th e a m ou n t o f d ist ance g a in e d to w ards th e new course (sho w n here f or 9 ° head i n g chan g e ). T actic a l Di a m eter - T actical d ia m e t e r i s th e d ist ance g a in e d to th e le f t or r ig h t o f th e or ig in a l course a f te r a tu r n o f 1 80 ° i s com pl et ed . Final Di a m eter - Final d ia m e t e r i s th e d ist ance perpe n d i cu l a r to t he or ig in a l course m easured f rom th e 180 ° po in t th rou g h 36 ° (sho w n here f or ste ady tu rning rad ius , R ) . Pi v ot Point - A ship ’ s pi v ot point is a point on t h e cente rl i n e a b o u t w hic h the ship tu rn s w h e n the ru d d e r is pu t o v e r . Drif t A ngle - D r i f t an g l e i s an an g l e a t any p o in t on th e tu rning ci r cle bet w een th e in te rsect io n o f th e ta n g en t a t t h at point and t h e ship ’ s keel l i ne. R eferenc e : ht t p://we b . n p s. n a v y . m il /~m e / t ss e /T S4 01 / s u p po r t / 1 - 11 - 1 . p df

285. F o r c e s Act i ng on Titanic's Ru d der 2 2 knot s H a r d O v e r 4 ° F o rc e on rud d e r  21 x A R V 2  R ( n e w t o ns) * A R is t h e ru d d e r are a in sq u ar e meters  R is t h e rud d e r an g le in de g rees V is v eloci t y of t h e shi p in met er s per second A re a of T ita n ic ' s rud d e r by Simpso n 's rule* * = 401. 7 f t 2 = 3 7. 3 m 2  R = 40° hard o v er V= 2 kn o t s = 10. 3 meters/sec F o rc e = 3,324,00 ne w t o ns = 33 4 long t o ns Rud der pressure = 0.8 3 t o ns/sq -ft * Equation i s f o r a s pad e s hape d rudde r . h tt p : / / ww w .s na m e . o r g /N A M E/ p ro b le m 7 . pdf ** h tt p :/ / ww w . en c y c lopedi a - t i t a n i c a . o r g / a r t i c le s / r u d de r _ w ee k s. p d f spade shapp e d rudder

286. Th e sh i p tu rn s b ec au s e o f h y d ro d y n ami c fo r c e s on th e hu l l , no t th e fo r c e acti n g o n th e ru dd e r . dire ct io n o f w a t e r f low dire ct io n o f s hi p m o v e m ent dire ct io n o f w a t e r f low dire ct io n o f w a t e r f low ru dde r f orce d e v e l op i n g t u rn - bu il d - u p o f hu ll f o r ces hul l f or ce rudder f or ce Dr a g a n d p ro p u l sive forc e s n o t sh o w n. dire ct io n o f w a t e r f low dire ct io n o f s hi p m o v e m ent dire ct io n o f w a t e r f low dire ct io n o f s hi p m o v e m ent dire ct io n o f w a t e r f low st r a ig h t ap p roa c h sta rt o f t u rn - h e lm pu s h e d o v er

287. Th e spee d o f a s hip in a tu r n w i ll d ec r ea s e du e to inc r ea s ed r e sistance. 4.53 Fo r T ita n ic : C B = . 684 T urnin g dia m e t e r = 385 ft Ship lengt h = 85 ft Approach s pee d 3 8 ft/s e c (22.5 k no ts) T urnin g dia m e t e r - t o - l e ng t h rat i o = 4 . 53 St ead y t urnin g s pee d- t o - a p p r o a ch s pee d rat i o = . 7 7 from abo v e Stea d y t u r n i n g s p ee d f o r T ita n ic = . 7 6 X approac h s pee d = 28 .9 ft/s e c ( 17 .1 k no ts ) A stead y t u rnin g rat e a t 1 7 kn o ts u n der hard helm f o r t h e fi n al dia m ete r of t u r n w orks o u t to a stead y sta t e t u rnin g rat e of 0.8 6 de g rees per secon d . R eferenc e : ht t p://we b . n p s. n a v y . m il /~m e / t ss e /T S4 01 / s u p po r t / 1- 11 - 1 . p df . 76

288. Wh a t Else D o We Know Abou t How a Ship Turns? T h e ship w ill he e l to w a r d the o utside of a turn. G = c ente r o f gra v i ty B = c en t e r o f bou y an cy GM = m e t a c en t e r height Bou y an cy f or ce = Weig h t o f s hi p ( W ) W  L = W  GM s in  = F C  H F C = W /g  v 2 /R T a k ing: H = 18 .6 ft GM = 2 .6 ft * W = 48 , 30 t on s * v = 2 9 ft/s e c i n t urn R = 19 2 5 ft  = 5 .4° h ee l a ng le f o r h a r d - o ve r f u ll s p ee d t u rn G B' w e i g h t of ship W bou y a n c y f o r ce w a t e r l i n e heelin g momen t arm H h y d r o d y n am ic hu ll f o r ce e qu a ls ce n tr e p it a l f o r c e F C right in g m o m en t ar m L Look i n g f or w ar d from a st ern durin g a t ur n to port (ex agge r a t e d v iew)  M B * B ed f o rd & H acke tt paper

289. An g le of He e l De v elopmen t Over Time Estimated an g le of heel f o r T ita n ic in a f u ll -spee d maximu m t u r n is 5. 4 ° t y pi c a l angl e- o f - h ee l de v elop m ent st ead y hee l angle Ad a pte d fro m : ht t p: / /w eb . n p s . n a v y .m il /~m e /t s s e / T S 4 1 / s u p p or t/ 1 - 11 - 1 . p d f

290. Wh a t Else D o We Know Abou t How a Ship Turns? F o r T itanic w ith 4 ° rud d e r d efle c ti o n: D rift - an gle rea ch e s ~ 8 ° an d th e head i n g cha ng e s a t 0.8 6 ° /sec in 3 r d ph as e .  st ead y -st a t e = 8 °  max = 40 ° Phases in a T urn 1 . Rudd e r t h r o w n . Ad a pte d fro m : ht t p: / /w eb . n p s . n a v y .m il /~m e /t s s e / T S 4 1 / s u p p or t/ 1 - 11 - 1 . p d f r s te ad y - s tate = . 8 6°/ s e c o n d 2 . S h ip sk i d s a n d d rifts ou t w hil e hu ll f o r ce s bu ild a n d sta rts to t u rn s h i p . 3 . A ll f o r ce s b a l a n ce ou t a n d s h ip sta y s in stea d y t u r n .

291. Det e rmining Pivot P o ints an d Dri f t Angles Th e d rift a ng le in d e g r ee s ca n b e taken a s β = 1 8 L /R (in d e g r ees ). Fo r T ita n i c , β = 7 . 9 5  8 ° . Th e l o cat i o n o f t h e p i v o t po i n t is X = R s i n β a h ea d o f t h e ce n ter o f g r a v ity o f t h e s h i p . Fo r T ita n i c , X = 26 6 ft a h ea d o f bu l k h ea d H , o r a bou t 15 9 feet b ac k fr o m t h e bo w (a pp . 1 /6 th s h i p l e ng t h ) und e r t h e f o r w a rd w e l l d eck. R e f eren c e : h tt p : / / w e b . np s. n a v y . m il / ~m e /tss e / T S 4 1 / s u p p or t/ 1 - 1 1 - 1 . pdf Path o f C G o f s h ip in t h e t u rn D rift a ng le  H ea d i n g a ng le  V e l o c ity v ect o r C e n ter o f t u rn D ir ect i o n o f s h ip m o v eme n t  =    Pi v o t po i n t C e n ter o f Gr a v ity ( C G) Stea d y t u r n i n g r a d i u s R 192 5 ft s h ip l e ng th L 85 ft B P X

292. Pivot P o int an d Drif t A n gle for the Titanic

293. Wh a t Ca n We Le a rn From Zi g - Zag M a neu v e r s? R eferenc e : ht t p://we b . n p s. n a v y . m il /~m e / t ss e /T S4 01 / s u p po r t / 1 - 11 - 1 . p df R es pon s e c u r v e f o r s h ip st udd i e d s ho w s a h ea d i n g c h a ng e o f 20 ° in 3 4 sec ond s fr o m t=0 b ef o re h e lm s h ifted to oppo s ite side. T r ack s c l o se ly a h ea d i n g c h a ng e o f 2 po i n ts in 3 7 sec ond s see n o n Ol ym p ic f o r a "h a r d - asta r b o a r d " h el m o r d e r w h e n r unn i n g a t 21 .5 k no ts. Stea d y t u rn r at e f o r t h is s h ip is 5 ° p er m i nu te (0. 8 3 ° p er sec ond ). Th is is a bou t t h e same t u r n i n g r at e f o r t h e T ita n ic in t h e stea d y t u rn ph as e und e r f u ll h e l m. W e ca n use t he d y na m ics o f f t h es e cur v e s to mo del t h e t u rning characteristic s of t h e T ita n ic f o r se v era l t y pes of t u rnin g maneu v ers. 3 4 sec 20 ° stea d y t u rn r at e o f 5 0° p e r m in °

294. S p r e a d S h e e t Anal y sis ... ... . . . s pee d ( k no t s ) s pee d ( f t/ s e c ) i n c r e m en t a l d i s t an c e i n 7 . 5 s e c pe r c en t m a x 22 . 5 38 285 100% i n i t i a l 21 . 3 36 270 95% 19 . 5 33 248 87% 18 . 4 31 233 82% 17 29 218 76% i n f u l l t u r n T i m e ( s e c ) r udde r ang l e ( deg ) h ea d i ng ( d e g) de l t a head i n g ang l e d r i f t ang l e ( deg ) c ou r s e ang l e ( deg ) X po s i t i o n ( f t ) Y po s i t i o n ( f t ) - 1 5 . 570 - 7 . 5 . 285 . 7 . 5 - 4 - 2 . -2 -2 - 28 5 15 - 4 - 5 . -3 -5 - 55 5 22 . 5 - 4 - 11 . -6 -6 -5 - 80 2 - 2 2 30 - 4 - 17 . 5 - 6 . 4 7 -8 - 9 . 4 7 - 103 2 - 6 37 . 5 - 4 - 23 . 9 - 6 . 4 7 -8 - 15 . 9 4 - 124 2 - 12 45 - 4 - 30 . 4 - 6 . 4 7 -8 - 22 . 4 1 - 144 3 - 20 3 52 . 5 - 4 - 36 . 9 - 6 . 4 7 -8 - 28 . 8 8 - 163 4 - 30 8 60 - 4 - 43 . 4 - 6 . 4 7 -8 - 35 . 3 5 - 181 2 - 43 4 67 . 5 - 4 - 49 . 8 - 6 . 4 7 -8 - 41 . 8 2 - 197 4 - 58 75 - 4 - 56 . 3 - 6 . 4 7 -8 - 48 . 2 9 - 211 9 - 74 2 82 . 5 - 4 - 62 . 8 - 6 . 4 7 -8 - 54 . 7 6 - 224 5 - 92 90 - 4 - 69 . 2 - 6 . 4 7 -8 - 61 . 2 3 - 235 - 111 2 97 . 5 - 4 - 75 . 7 - 6 . 4 7 -8 - 67 . 7 - 243 3 - 131 3 105 - 4 - 82 . 2 - 6 . 4 7 -8 - 74 . 1 7 - 249 2 - 152 3 112 . 5 - 4 - 88 . 6 - 6 . 4 7 -8 - 80 . 6 4 - 252 8 - 173 8 120 - 4 - 95 . 1 - 6 . 4 7 -8 - 87 . 1 1 - 253 9 - 195 6 127 . 5 - 4 - 101 . 6 - 6 . 4 7 -8 - 93 . 5 8 - 252 5 - 217 3 135 - 4 - 108 . 1 - 6 . 4 7 -8 - 100 . 5 - 248 7 - 238 8 420 - 4 - 353 . 9 - 6 . 4 7 -8 - 345 . 9 1 - 24 2 - 4 7 427 . 5 - 4 - 360 . 4 - 6 . 4 7 -8 - 352 . 3 8 - 45 8 - 1 8 435 - 4 - 366 . 9 - 6 . 4 7 -8 - 358 . 8 5 - 67 6 - 1 4

295. Titanic's T u rning Cir cle Mo d e l Results

296. Titanic's T u rning Cir cle With S h i p Prof i les O v erla i n A d v ance 2540 ft 90 ° T r ansfer 1740 ft T actic a l dia m eter 3880 ft Final Di a m eter 3860 ft

297. 1 1 : 4 PM on 1 4 Apri l 1 9 1 2 What the Britis h I n qu i r y S aid Report on the Loss of the SS T i t anic 30th day of Jul y , 1912 The s h ip appea r s to h ave r u n o n , on t h e s ame co u r s e, u n til, at a l ittle before 1 1.40, one of the look-outs in the crow ’ s nest str u ck th r ee blows on the go n g, w h i c h was the ac c ep t ed war n ing for something ahead, fol l owing this i m m e dia t e l y aft e rwa r ds by a t e l e pho n e m e s s age to the b r idge “Iceberg rig h t ahead.” Al m ost simultaneou s ly wi t h the th r ee gong signal M r . M u rdoch, the o f fi c er of the watch, gave the o r der “Har d -a- starboa r d,” and i m m e dia t e l y t e l e grap h ed down to the engine r oom “ S top. F u ll speed astern.” The helm was already “ h ard o v e r ,” and the s h ip ’ s head h ad fal l en o f f about two points to port, w h en s h e co l l i ded wi t h an i c eb e rg we l l forwa r d on her starboa r d side.

298. 1 1 : 4 PM on 1 4 Apri l 1 9 1 2 Concl u si o n of the Britis h I n qu i ry Report on the Loss of the SS T i t anic 30th day of Jul y , 1912 F r om the e v ide n ce given it appea r s that the “ T ita n i c ” h ad t u r n ed abo u t two poi n ts to port before the coll i sion oc c u r re d . From v ario u s e xperi m ents s u bsequently made wi t h the S .S. “ O l y mp i c , ” a sister s h ip to the “ T i t anic , ” it was fou n d that travel l ing at the same r ate as the “ T i t anic , ” about 37 seconds wo u ld be req u ired for the s hip t o change her c ou r se to this ex t ent aft e r the h e l m h ad be e n put har d -a-starboa r d. In this t i m e the s hip would travel abo u t 466 yards, a n d al l owing for the few seconds that wo u ld be nec e s s ary for the order to be gi v en, it may be as s umed that 500 yards was about the distance at w h i c h the i c eb e rg was sighted e i ther from the b r idge or c row ’ s nest.

299. What Abou t the Engines Stopping or R e v e r sing? T r i mm er T h o m as D il lo n: "They st o pped . . . abo u t a m inute and a ha l f [ a fter the c o llisi o n ] . They [then] w ent slow astern . . . about a m inute and a half [later f o r] about t w o m inutes . " G re a ser T h o m a s Range r : " W e turned r ound and loo k ed into the eng i ne r oom and saw the turbine engine w as st o pped . . . T h e re a re t w o a r m s [t hat ] c o m e u p a s t h e t u r b i n e e ng i n e st op s ... [that w as] about t w o m inutes after w a rds. . .[ a f t er the ja r .]" 1st Class P assenger Henry Sten g el: " A s I w o k e up I heard a s l ight cr a sh. I pa i d no attent i o n to it until I heard the eng i nes st o p. . .[They w e r e st o pped] I sh o uld say t w o or th r ee m inutes, and then they st a rted again just sligh t l y ; just st a rted to m ove again. I do not k now w hy; w hether they w e r e bac k ing off, or not." 1st Class P assenger G e o rge Rhei m s: "I did not notice that the engines w e r e st o pped right a w ay; they w e r e not stopp e d right a w a y ; of that I am p ositive. [I felt a chan g e w ith r efe r ence to the eng i nes] a few m inutes after the shoc k , possib l y t w o or th r ee m inutes; m ight have been le s s." 2nd Class P assenger L awrence Bee s ley: "The r e ca m e w hat see m ed to m e nothing m o r e than an e x tra heave of the eng i nes and a m o r e than usually obvio u s dancing m otion of the m att r e s s. . . and p r e s ently the s a m e thing r epe a ted w ith about the sa m e inten s it y . . .I c o ntinued m y r e a ding. . .But in a few m o m ents I fe l t the engines slow and st o p." T h e e n g i n e s d i d not stop nor r e v e r s e u ntil som e sh o rt a m o unt of time afte r th e s h i p s truck the ic eberg.

300. A p pl y ing the Mo d el The turning mode l ca n be used to anal y ze se v eral scenari os i n cl u d i ng: The c l assi c "har d-a- starbo a rd " maneu v e r . A n a tte mpte d "por t - around " maneu v e r . A dela y e d "har d-a-port" maneu v e r .

301. We Also Ne e d A T y pical Ice berg Passen g er H enry Stengel: "I noticed, a very large one, w hich loo k ed s o m ething li k e the Rock of G ibralta r ." AB Sea m an Jose p h Scarrott: "It r ese m bled the Rock of G ibraltar loo k ing at it f r om Eu r opa Poin t ." QM Olliver: "The iceberg w as about the height of the boat dec k ; if anything, just a li t tle highe r . It w as al m ost alongside of the boat, si r . The top did not touch the side of the boat, but it w as al m ost alongside of the boat . " 2 5 f t v isi b le portion a ll o w in g f or under w a te r con to ur M odel f or a 2 di m en t ional plot

302. T h e "Hard -a- Starb o a r d" Scena r io 7. 5 S econ d I n cre m ent s S h o w n on a 500 ' X 500 ' Gr i d

303. What D o t he T u rning Mo d e l Resul t s Sa y ? A turn of " h a r d - a - st a rboard " 3 7 s e con d s before col l isio n w i th no oth e r cor r e cti v e a ctio n w o u l d ha v e l i k ely prod uce s e v e r e dam age along the entir e st a rboard side.

304. Rea l ity an d Co n tr adi ction QM HICHENS A T THE AMER I C A N I N QUI R Y QM H i chens: "T h e sixth offic e r r epeated the orde r , "T h e helm is hard astarboard, si r ." B u t, d u r i ng the tim e , s h e w as c r u s hi n g the i c e, or w e could hear the g r i n d ing n oise alo n g the s h ip's b ottom. I heard t h e te l egra p h r i n g, si r ." QM HICHEN S ' FIR S T RE S P O N S E A T THE B R IT I SH I N QUI R Y 951. Had y ou time to get the h e l m hard a starboard befo r e s h e struck? - [QM Hi c h en s ] N o , sh e w as c r a sh ing t h en. QM HICHEN S ' CONT R A D I C TION 957. Befo r e t h e vessel s truck had y ou had time to get the w heel r i ght ove r ? - [QM H i chens] T h e w heel w as over then, hard ove r . 958. (The Commis s ione r .) Befo r e s h e struck? - Oh y es, hard over befo r e s h e struck.

305. S om e Rea l ity Chec k s QM Alfred Oll i v e r: " I know the ord e rs I hea r d w hen I w as on the bridge w as aft e r w e had stru c k the i c eb e r g . I he a rd h a r d aport, and th e r e w as the man at the w heel and the offi c e r . The offi c er w as seeing it w as ca r r i ed out r ight." AB Sea m an Joseph Scarrott: " Un d er port helm. Her stern w as sle w ing off the i c eb e r g . Her starboard quart e r w as go i ng off the iceb e r g , and the starboard bow w as go i ng as i f to make a ci r c l e r ound it . " Fireman Alfred S hier s : " I saw the be r g that w as go i ng a w a y . . . on the starboard quart e r , off the stern."

306. S om e Rea l ity Chec k s Was the Ice b er g Real l y Dea d Ahead? T h is sketc h (s h o w n here w ith in v erte d colors ) w a s dra w n by L o ok o ut Frederick Fleet to show h o w t h e b er g ap p eared w hen first sigh ti n g . Not ice h o w he placed t h e berg sligh t l y o f f t h e starboar d b o w of t h e ship , n o t dead ahead of he r . Fleet occ u pied t h e p o r t si d e of cro w ' s n es t w hile Lee had t h e starboar d side. Despit e w hat he t o ld Senat o r Smit h , t h is v iew ma y explain a n ap p aren t delay in ge t ti n g a n i mmed ia t e resp o n s e fr o m t h e brid g e w hen t h e 3 bell w arnin g w a s gi v en. Se n at o r S M I TH . Th e y s w un g t h e s h i p 's bo w a w a y fr o m t h e ob j ect? M r . FL EE T . Y es ; b eca u s e w e w e re mak i n g st r a i gh t f o r it.

307. Time From 3 - Bel l L o okout Wa r ning to Colli sion Lo o kout Fre d rick Fleet: "I saw this black thing loo m ing up; I didn’t k now w hat it w as. I as k ed Lee if he k new w hat it w as. H e couldn’t s a y . I thou g ht I bet t er ring the bell. I rang it th r ee ti m es." [Interview w ith Leslie Reade] QM R o bert H ichens: " [ The first notice that the r e w as s o m ething ahead w as] th r ee gongs f r om the c r o w 's - nest, Si r . . . W ell, as near as I can t ell you, [it w as] about half a m inu t e [ b e f o r e t h e order ca m e ' H ar d - astarboard'] . " [British Inquiry 96 9 - 973] QM Alfred Olliver: "When I w as doing t his bit of duty I heard th r ee bells rung up in the c r o w 's nest, w hich I k new t hat it w as s o m ething ahead...When I heard t he r eport, I loo k ed, but could not see anything, and I le f t that and ca m e w as just entering on t he bridge just as the sh o ck ca m e." [ A m eri c an Inquiry] IT T A KE S A B O U T 4 5 SE C O ND S ON A VE R A G E T O W A LK FR O M THE S T A N D A RD C O M P A SS PL A T F O R M T O THE BRID G E N O T C O UNTING RE A CTI O N TIME. T ime from 3- bell l o o kou t w a r n i n g to c o l l i sion w o u l d be ab out 50 - 60 s e con d s ba s ed o n QM O l l i v e r's r e p o rt e d a ctions. Ic eberg sp o tted som e shor t time e a r l i e r by Fred e ric k F l e et. W e r e a l ly d o n 't kno w w hat time Murd o ch first spotted the ic eberg.

308. Mo d el i ng a " P o r t - a r o u n d " Maneuv er

309. Mo d el i ng a " P o r t - a r o u n d " Maneuv er 92 f t 882 f t OA Sett in g t h e headin g angle. 26 . 2 5 - 4 - 16 . - 5 - 7 . - 9 - 93 1 - 5 T i m e ( s e c ) r udde r ang l e ( deg ) h ea d i ng ( d e g) de l t a head i n g ang l e d r i f t ang l e ( deg ) c ou r s e ang l e ( deg ) X po s i t i o n ( f t ) Y po s i t i o n ( f t ) - 1 5 . . 570 . . 3 . 7 5 - 13 . 3 - . 5 - . 5 - . 5 - 14 3 7 . 5 - 26 . 7 - 2 . - 1 . 5 - 2 . - 28 5 11 . 2 5 - 4 - 3 . 6 - 1 . 6 - 3 . 3 - . 3 - 42 4 -1 15 - 4 - 5 . 5 - 1 . 9 - 4 . 5 -1 - 55 9 -3 18 . 7 5 - 4 - 8 . - 2 . 5 - 5 . 5 - 2 . 5 - 68 9 -9 22 . 5 - 4 - 11 . -3 - 6 . -5 - 81 2 - 2 30 - 26 . 7 - 19 . -3 - 6 . - 1 3 - 104 4 - 8 33 . 7 5 - 13 . 3 - 22 . -3 - 4 . 5 - 17 . 5 - 115 2 - 13 9 37 . 5 - 22 . 5 - . 5 - 3 . - 19 . 5 - 125 4 - 17 5 41 . 2 5 13 . 3 - 22 . 5 - 2 . - 20 . 5 - 135 7 - 21 4 45 26 . 7 - 22 . . 5 - 1 . - 2 1 - 145 8 - 25 3 48 . 7 5 40 - 21 . 5 . 5 . - 21 . 5 - 156 - 29 3 52 . 5 40 - 19 . 5 2 1 . - 20 . 5 - 166 2 - 33 1 56 . 2 5 40 - 17 . 2 2 . 3 2 . - 19 . 2 - 176 5 - 36 7 60 40 - 14 . 5 2 . 7 3 . - 17 . 5 - 186 9 - 39 9 63 . 7 5 40 - 11 . 6 2 . 9 4 . 5 - 16 . 1 - 197 3 - 43 67 . 5 40 - 8 . 4 3 . 2 5 6 . - 14 . 3 5 - 207 9 - 45 7 71 . 2 5 40 - 5 . 1 3 . 2 5 7 . - 12 . 1 - 218 6 - 47 9 75 40 - 1 . 9 3 . 2 5 8 . - 9 . 8 5 - 229 3 - 49 8

310. " P or t- a r o u n d " Scena r io — Did It Happe n Like This? 3.7 5 S econ d I n cre m ent s S h o w n on 250 ' X 250 ' gr i d

311. SU M MARY AN D CO N CL U SIONS A turning mode l w a s de v elope d f or SS Titanic based on repor t e d obser v a tions of Titanic an d Oly m pic an d gener i c ship maneu v erin g chara c te ris t ics Model appl i e d to a sprea d shee t for anal y sis m od e l us e s r e a li s tic pa rame t e r s s uch a s sp ee d r e du c tion in a tu rn an d drift an gle data g i v e s he a d i ng ang l e , cours e a n gle, an d X - Y co o rdi n at e s a s fun ction of time r e sult s allow for an i m atio n anal y sis The class i c co l l i si o n w he r e the sh i p si d e s w i p e s a n ice b er g 37 second s foll o w ing a "har d-a - sta r board" order does not ho l d up. Se v era l a lternat i v e scen a rio s ha v e been considered a p o rt - a r o u nd t y pe of m an e u v er a d e la y e d ha r d - a - po r t only m a neu v e r The m odel ca n be easil y ex t ende d to look a t other scen a rios