CHAPTER 4 EFFECT OF WEATHER TO SHIPPING.pdf

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1. BML 3623 - METEOROLOGY
CHAPTER 4
EFFECT OF WEATHER TO SHIPPING OPERATIONS
PREPARED BY: NUR AMIRA ADAM

2. Course content outline and
subtopics:
✓Wind
✓Wave
✓Fog
✓Cloud
✓Sea state scale
✓Beaufort Scale

3. Collision between the Danish passenger ship EXPRESS 1 and the Polish tour boat
BALTIC CONDOR off Rønne on 10 May 2019
https://safety4sea.com/dmaib-investigation-collision-of-ships-in-heavy-fog/

4. EXPRESS 1BALTIC CONDOR

5. RESTRICTED VISIBILITY NAVIGATION

6. A lookout involves continuously
observing the surroundings using
sight, hearing, and any available
technology to detect potential
hazards, other vessels, navigational
markers, weather changes, and
more. It's essential to maintain
vigilance and alertness to prevent
collisions, groundings, and other
accidents, especially in busy or
challenging maritime
environments.

7. RESTRICTED VISIBILITY NAVIGATION
•Visibility is a measure of the distance at which an object or light can be clearly
recognized.
•Visibility may be restricted by heavy rain, snow, blown spray, low cloud, mist
and fog, and in some parts of the world blown sand, and smoke.
•In any sea voyage, visibility is one of factors that determines the safety,
smoothness, and seaworthiness of the voyage.

8. RESTRICTED VISIBILITY NAVIGATION
•Fog is defined as excess water vapour in the air, reducing visibility to 1 km or
less.
•Visibility at sea is associated with:
i. Air temperature – formation of fog
ii. Winds – motion of fog and haze
iii. Humidity – formation of fog
iv. Particulate matters – formation of fog; haze

9. • Mist is the suspended water droplets at a lower density as compared to fog.
• Mist typically is quicker to dissipate and can rapidly disappear with even slight winds.
• Visibility in mist lies between 1 to 2 km.

10. FORMATION OF FOG
•Fog is a tiny droplet of water, formed by condensation of water vapor in the
water, with the base at the surface of the earth.
•Visibility codes of fog are presented in G246 under international codes.
•2 types of fog:
1. Advection fog
2. Radiation fog
3. Upslope fog
4. Frontal fog
5. Ice fog
6. Steam fog

11. TYPES OF FOG
Advection fog
•Advection fog forms when warm, moist air moves horizontally over a colder
surface, causing the air near the surface to cool and reach its dew point, leading
to condensation and fog formation.
•It typically occurs in coastal areas where warm, moist air from the sea moves
over cooler land surfaces.
•Advection fog can reduce visibility significantly and tends to persist until the
wind changes direction or the air temperature warms significantly.

12. Advection fog

14. TYPES OF FOG
Radiation fog
•Radiation fog forms on clear nights when the ground loses heat through
radiation, causing the air near the ground to cool. If this cooling reaches the dew
point temperature, condensation occurs and fog forms.
•It commonly occurs in valleys and low-lying areas during cool, clear nights with
light winds.
•Radiation fog usually dissipates after sunrise as the ground warms up due to
sunlight.

18. COLREG - Preventing collisions at sea

19. SEA STATE
•Sea state refers to the condition of the sea's surface, primarily determined
by wave height, wave period, and wave steepness.
•It affects ship stability, navigation, and the safety of maritime activities.
•Sea state is often classified using various scales, such as:
i.Douglas Sea Scale
ii.Beaufort Scale
•Understanding sea state helps sailors and maritime professionals make
informed decisions about when and how to navigate the waters safely.

20. DOUGLAS SEA SCALE
•Douglas sea scale is a system used to measure and classify the height of
waves in the sea.
•It was developed by Captain H. T. Douglas, a British naval officer, and is
primarily used by mariners and meteorologists to describe the sea state
based on observations of wave height.
•The scale ranges from 0 (calm seas) to 9 (very high seas), with each number
corresponding to a range of wave heights and associated sea conditions.

21. ‘Sea’ is a description of the
wind waves raised by the
wind in the immediate
neighbourhood of the
place of observation at
the time of observation.
‘Swell’ is a description of
the ocean waves that are
not raised by the local
wind (produced by distant
wind).

23. •The Beaufort Scale is a system for measuring and classifying wind speeds based
on the observed effects of wind on the sea's surface and on land features.
•The Beaufort Scale was named after Sir Francis Beaufort who introduced it in
1805.
•It is widely used by sailors, meteorologists, and others to estimate wind strength
visually or by the feel of the wind.
•The Beaufort Scale originally ranged from 0 to 12, with each number
corresponding to a range of wind speeds and their observable effects.
BEAUFORT SCALE

24. Each category
describes not
only the wind
speed range but
also the visible
effects on the
sea surface,
waves, and on
land features.

26. Impacts of Weather on Marine Transportation
•One o the greatest threats to the safety of marine transportation is adverse weather
conditions.
•Hurricanes, in particular largely affect the ability of ships to safely navigate through
the oceans.
•In cases where hurricanes and other forms of strong winds and waves block the
paths of ship in the ocean.
•Shipping companies have to adjust their routes or cancel the expeditions altogether.
•Some adverse weather conditions such as frozen oceans and seas can also impede
the ability of ships to safely navigate through their prospected routes.

27. Inaccessibility of ports
•Climatic changes in the recent past, such as rising oceans, often lead to
accompanying effects of flooding and the accessibility of ports to ships.
•In cases where rising oceans affect the area around major ports, ships are unable
to dock safely.
•In rare cases, a drop in the ocean water levels leads to inaccessibility of ports.
•Shipping companies, therefore,havetoreadjusttheirshippingdestinations.

28. Underwater Keel Clearance is the vertical distance between the lowermost point of a floating vessel
and the nearest fixed physical feature underneath the water at a certain point in time.
Example, if a vessel has a
draft of 10 m and the
available depth of water
is 100 m, the Underwater
Keel Clearance is 90
metres.

30. Destruction of Infrastructure
•Marine shipping infrastructure, including ports and ships, are all alike at the mercy of
weather elements.
•Even the strongest and most robust shipping infrastructures such as ports and ships
can be destroyed by hurricanes.
•Ports can also be subjected to severe weather elements, leading to the destruction
of port infrastructures such as cranes and docking bays.
•This sabotages the shipping companies' ability to facilitate seamless transportation
and distributionofgoods.

31. Tsunami

32. Impacts on Shipping Companies
•These three main areas largely summarize the effects of weather elements in
maritime transportation.
•Shipping companies can, therefore, be forced to either cancel their shipping
expeditions or readjust their shipping schedules in tandem with the weather
conditions.
•This has a major impact on businesses ability to meet their production targets as well
as other forms of supply chain management.
•The delayed delivery of goods becomes too costly for all businesses and parties
involved in maritimetransportation.

33. THANK YOU