ship-machinery- presentation details .pdf

ships and machinery

1. Chapter 1
Ships and machinery

21. Introductiontomarineengineering,bytakinganoverall
lookattheship.
1.Thevariousdutiesofamarineengineerallrelatetothe
operationoftheshipinasafe,reliable,efficientand
economicmanner.
2.Themainpropulsionmachineryinstalledwillinfluencethe
machinerylayoutanddeterminetheequipmentand
auxiliariesinstalled.
Determinetheoperationalandmaintenancerequirements
fortheshipandthustheoperationknowledgefirstis
required.
Thedutiestobeperformedbythemarineengineer.

22. What are the Ships?
large, complex vehicles which must be self-sustaining in
their environment for long periods with a high degree of
reliability.
A ship is the product of two main areas of skill, those of the
naval architect and the marine engineer.
The naval architect -is responsible with the hull, its
construction, form, habitability and ability to endure its
environment.
The marine engineer-is responsible for the various
machinery systems which required propelling and operating
the ship.

23. What are the Machinery required to propel and operate
the ship are;
Mainengines-dieselengine,steamturbine,gasturbine,
nuclearreactor
Steeringgear,
anchoring
shipsecuring/mooring
cargohandling,
airconditioning,
powergenerationanditsdistribution.
Some overlap responsibilities between naval architects
and marine Engineers are;
Propellerdesign,
Reductionofnoiseandvibration.
Ship'sstructure,
Engineeringservicesprovidedtoconsiderableareasofthe
ship.

24. A ship may be divided into three major areas:
1.the cargo-carrying holds or tanks,
2.the accommodation
3.and the machinery space.
Dependinguponthetypeeachshipwillassume(take
responsibility)varyingproportionsandfunctions.
Oiltankerwillhavethecargo-carryingcompartment;
Dividedintotanksbytwolongitudinalbulkheadsand
severaltransversebulkheads.
Therearequantitiesofcargopipingbothaboveand
belowdecks.

25. Thegeneralcargoshipwillhave;
variouscargoholdswhichareusuallythefullwidthofthe
vesselandformedbytransversebulkheadsalongtheship's
length.
Cargohandlingequipmentlocatedondeck
Largehatchopeningsclosedwithsteelhatchcovers.
Theaccommodationareas.
Eachtypeoftheseshipwillhaveasufficienttomeetthe
requirementsfortheship'screw,provideanavigating
bridgeareaandacommunicationscentre.
Themachineryspace/compartment-thesizewillbe
decidedbytheparticularmachineryinstalledandthe
auxiliaryequipmentnecessary.

26. Passenger ship
would have a large accommodation which considered as the
'cargo space'. Machinery space may be large because for
installation of;
Air conditioning and refrigeration equipment,
Stabilisers
Other passenger related equipment.

27. Machinery Arrangement.
Threeprincipaltypesofpropulsionmachineryinstallation
layoutsfromanengineeringpointofview;
1.Slow-speeddieselengines,directcoupledbetween
propellershaftanddieselengines-100-120RPM
2.Medium-speeddieselsoperatesintherange250-750
RPMcannotdirectlycoupledtothepropellershaft.A
gearbox/reductiongearisusedtoprovidealowspeed
driveonpropellershaft.
3.High-speedSteamturbinerunningintheorder6000RPM.
Agearbox/reductiongearmustbeusedtoprovidealow
speeddriveforthepropellershaft.

28. For the propeller to rotate and operate efficiently:
Must rotate at a relatively low speed at about 80-100RPM
The slow-speed diesel enginerotates at this low speed and
the crankshaft is thus directly coupled to the propeller shafting.
No need use gear box.
The medium-speed diesel engineoperates in the range
250—750 rev/min and High-speed dieseloperates in the
range 1000RPM above must not be direct coupled to the
propeller shaft. So, a gearbox is used to provide a low-speed
drive for the propeller shaft.
The steam turbine
Rotates at a very high speed, about 6000 rev/min. Again, a
gearbox must be used to provide a low-speed drive for the
propeller shaft.

29. Slow-speed diesel engine.
AcutawaydrawingofacompleteshipisshowninFigureI.I.
Besidesthemachineryspace,canbeseen
1.themainengine
2.thecargoheatingboiler.
3.Structureofthehull,
4.cargotankareastogetherwiththecargopipingandthe
deckmachinery.

30. FigureI.I.

31. Figure1.2Slow-speeddieselmachineryarrangements

32. Themoreusualplanandelevationdrawingsofatypicalslow-
speeddieselinstallationareshowninFigure1.2.
Asix-cylinderdirect-drivendieselengineisshowninthis
machineryarrangement.
Theonlyauxiliariesvisibleare;
1.Dieselgenerator
2.Aircompressor,
3.Generators,
4.Oily-waterseparator,
5.Evaporator,
6.Variouspumps
7.Heatexchangers.
8.Auxiliaryboiler
9.ExhaustgasheatexchangerwouldbelocatedinUptake
regionleadingtothefunnel.
10.Variousworkshopsandstores
11.Machinerycontrolroom/enginecontrolroom.

33. Gearedmedium-speeddiesel.(Usinggearbox)
Four(4)medium-speed(500rev/min)dieselsareusedin
themachinerylayoutoftherailferryshowninFigure1.3.
Thegearunitsprovideatwin-screwdriveat170rev/min
tocontrollablepitchpropellers(CPP).
Thegearunitsalsopowertake-offsforshaft-driven
generatorswhichprovideallpowerrequirementswhileat
sea.

34. Figure1.3Medium/high-speeddieselmachineryarrangements

35. Steamturbine.
Twincross-compoundedsteamturbinesareusedinthe
machinerylayoutofthecontainership,showninFigure
1.4.
Onlypartplansandsectionsaregivensincethereisa
considerabledegreeofsymmetryinthelayout.Each
turbinesetdrives,throughadoublereductiongearbox
withseparatethrustblock,itsownfixed-pitchpropeller.
Thecondensersarelocatedbeneatheachlow-pressure
turbineandarearrangedforscoopcirculationatfull
poweroperationandaxialpumpcirculationwhen
manoeuvring.

39. Around the main machinery are located various main engine and
ship's services pumps, an auxiliary oil-fired boiler and a sewage plant
and 3 diesel alternators.
The 8.5m platform is located;
Turbo-alternator each side and fitted the forced-draught
fans for the main boilers.
The main boiler feed pumps and other feed system
equipment are also located around this flat.
The two main boilers occupy the after end of this flat and
are arranged for roof firing.
Two distillation plants are located forward and the domestic
water supply units are located aft.
The control room consists the main and auxiliary machinery
consoles.
The main switchboard and group starter boards are located
forward of the console, which faces into the machinery
space.

40. On the 16.2 m platform.
is the combustion control equipment for each boiler with a
local display panel, although control is from the main
control room.
The boiler fuel heating and pumping module is also
located here.
The de-aerator is located high up in the casing and
silencers for the diesel alternators are in the funnel casing.

41. Operation and Maintenance.
1)Themarineengineerresponsibleforalltheshipboard
machinerywiththeexceptionofradioequipment.
2)Electricalengineersmaybecarriedonverylarge
ships,ifnotelectricalequipmentisalsomaintainedby
marineengineer.
3)Amarineengineermusthaveabroad-based
theoreticalandpracticaltrainingashemustbea
mechanical,electrical,ventilation,airconditioningand
refrigerationengineerwhentheneedrises.

42. Theoretical and practical training is therefore
necessary for a marine engineer.
Hemustbeamechanical,electrical,air-conditioning,
ventilationandrefrigerationengineer,astheneedarises.
Unlikehisshore-basedoppositenumberinthese
occupations,hemustalsodealwiththespecialized
requirementsofafloatingplatforminamostcorrosive
environment.
Furthermorehemustbeselfsufficientandcapableofgetting
thejobdonewiththefacilitiesathisdisposal.

43. END