THE SHIPS

THE SHIPSThere are two main parts to a ship;

1. The Hull: Actual shell, body of the ship2. The Machinery: Includes both machinery to

drive her and ancillary equipment serving the electrical installations, winches and refrigerated accommodation.

http://www.maerskline.com/tr-tr/countries/int/news/news-articles/2013/10/discovery-channel-triple-e

 

Plan of steamship

THE HULLThe rear portion of the ship is termed aft, and

the extreme rear end is called the stern. When moving stern first, the vessel is regarded as moving astern.

The front portion of the ship is termed for-ward, whilst the extreme forvard end is called the bows. When moving bows first, the vessel is regarded as moving ahead.

Fore and aft are related terms, and often mean the same as bows and stern.

The area between the forward and aft portions of the vessel is called amidships (midships). The overall breadth of the vessel, which is found in the amidship portion, is known as the beam.

The propeller shaft, linking the propeller with the engines, passes through a shaft tunnel.

The ship's anchors and the windlasses used to lower and raise them are found in the bows.

Ship’s actual design and the number of decks will depend on the trade in which she plies. A tramp, carrying shipments of coal or ore, will be

a single deck vessel with large unobstructed hatches to facilitate loading and discharge.

A cargo liner, conveying a variety of cargo in relatively small consignments, would have 'tween decks’ to facilitate stowage.

Flush 'tween deck hatch covers are frequently provided so that fork lift trucks can be used in the holds.

The derricks are the ship's cranes, and their lifting capacity can vary from 1/2 ton to 50 tons.

When heavy items such as locomotives or boilers are commonly carried, jumbo derricks capable of lifting up to 200 tons are provided.

They are operated by the ship's winches. Derricks are very necessary when cargo is

loaded or discharged into barges and are also used on the ship's quayside, where they can work in conjunction with shore cranes.

The derricks are affixed to the masts.

The bridge of a vessel is the navigating centre of the ship where her course is determined.

In some cases (eg; fog), it is the practice to provide two navigating bridges, one situated aft and the other amidships.

Included in the navigating bridge accommodation is the helm, and also a large amount of nautical equipment, including radar screens, gyro-compass, radio direction finder, etc.

The bridge is in direct telecommunication with all parts of the vessel.

Crew accommodation on modern cargo ships and tankers is situated aft in close proximity to the machinery.

THE MACHINERY A Diesel engine is a form of internal-combustion engine,

in which combustion of the fuel takes place inside the engine.

The air in the cylinder is compressed to a high pressure so that it attains a high temperature and when oil-fuel is injected, it immediately ignites.

The power thereby produced is transmitted through a gearbox or dircctly to the propeller-shaft and is described in terms Brake Horse Power,‘BHP’.

Steam: Some larger ships are propelled by steam plant;machinery which converts the heat energy in steam into mechanical energy to turn the propeller shaft.

Marine steam plants can be divided into;1)Steam Reciprocaling Engines2)Steam Turbines3) A combination of 1 & 24)Turbo-electric.

* RPM:Revolutions per minute

Other Propulsion Forms:

Bunker Fuels: Virtually all merchant ships rely on oil-fuel for

both steam-turbine and for diesel-engined plants, oil having the advantage over coal in thal it is both readily and widely available, as well as being relatively easy to handle, store, and move about on board.

Oil-fuel is a derivative of crude-oil wlıich has been proccssed into distillate and residual fuel-oil.

Scales are used to deseribe the various grades and qualities of marine fuel-oils available.

LoadlineThe draft of a vessel is the depth necessary to

submerge her to her loadline. The loadline varies according to the seasons and

waters in which she plies. The seasons to which the markings apply are

Tropical (T), Summer (S), Winter (W) and Winter North Atlantic (W.N.A.) The world has been mapped off into sections showing where those sections apply.

Freeboard is the distance measured amidships from the loadline to the actual freeboard deck of a vessel.

This is the main deck in a single 'tween deck’ vessel and top continuous deck in a ship with two or more decks.

Loadline

TYPES AND METHODS OF TONNAGE MEASUREMENT

Deadweight tonnage (d.w.t.) expresses the number of tons (of 2240 pounds) a vessel can transport of cargo, stores and bunker fuel.

It is the difference between the number of tons of water a vessel displaces 'light' and the number of tons it displaces when submerged to her loadline.

Deadweight tonnage is used interchangeably with deadweight carrying capacity. A vessel's capacity for weight cargo is less than its total dead-weight tonnage.

TYPES AND METHODS OF TONNAGE MEASUREMENT

Cargo tonnage is a weight or measurement (W/M). The weight ton in the US and in UK countries

is the American short ton of 2000 pounds, or the English long ton of 2240 pounds.

A measurement ton is usually 40 cubic feet, but in some instances a larger number of cubic feet is taken for a ton.

Most ocean package freight is taken at weight or measurement (W/M) ship's option.The metric ton of 1000 kg., or cubic metre is becoming more widely used.

Displacement of a vessel is the weight in tons of 2240 pounds of the ship and its contents.

It is the weight of water the ship displaces. Displacement light is the weight of the vessel with

out stores, bunker fuel, or cargo. Displacement loaded is the weight of the vessel

plus cargo, passengers, fuel and stores.Gross tonnage applies to vessels, not to cargo. It is determined by dividing by 100 the contents in

cubic feet of the vessel's closed-in spaces, and is usually referred to as the gross registered tonnage (G.R.T.). A vessel ton is 100 cubic feet. it is used as a basis for

Pilotage and Dry Dock, and sometimes Tonnage Dues.Additionally, it is employed for statistical purposes, when

comparing ship sizes, and as a basis for Protection and Indemnity club entries.

Net tonnage is a vessel's gross tonnage less deductions of space occupied by accommodation for crew, machinery, fuel, stores and other accommodation which does not represent earning capacity of the ship. A vessel's net tonnage expresses the space available for

the accommodation of passengers and stowage of cargo, and is usually referred to as net registered tonnage (N.R.T.).

A ton of cargo in most instances occupies less than 100 cubic feet: hence the vessel's cargo tonnage may exceed its net tonnage, and indeed the tonnage of cargo carried is usually greater than the gross tonnage.

It is the cubic capacity of all earning space, and it is on this tonnage figure that most harbour dues and other charges are calculated. The aim of the average shipowner is to achieve a low net tonnage consistent with a maximum cubic capacity for cargo and/or passengers.

TYPES OF SHIPSThe type of merchant vessel employed on a

trade route is determined basically by the traffic carried.

1. General Cargo Ships2. Bulk Carrier3. Container Ships4. RO/RO5. Heavy Lift6. Tanker7. Combination Carrier8. Gas Carrier9. Passanger Ship10. Off-Shore and Towage11. Coaster12. Miscellaneous Ships 

General Cargo ShipCarry packaged items

like food, furniture,machinery

Tweendeckers; with two or more decks

Carry bulk cargo in lower holds, palletised or baled goods in the tweens.

Refrigerated ShipsReefer ships are

cargo ships typically used to transport perishable commodities which require temperature-controlled transportation, mostly fruits, meat, fish, vegetables and other foodstuffs.

Bulk ShipBulk carriers used to

transport bulk cargo items such as ore, rice,cement,lumber& paper products sugar and etc.

Large box-like hatches on its deck, designed to slide outboard for loading.

Container ShipContainer ships are

cargo ships that carry their entire load in truck-size containers.

Inter-modal shipmentInformally known as

"box boats" Carry the majority of

the world's dry cargo.

BargeA barge is a flat-

bottomed boat, built mainly for river and canal transport of heavy goods.

Most barges are not self-propelled and need to be moved by tugboats towing or towboats pushing them.

Roll-on/roll-off shipsRoll-on/roll-off ships is

designed to carry wheeled cargo such as automobiles and trailers.

RORO vessels have built-in ramps which allow the cargo to be efficiently "rolled on" and "rolled off" the vessel when in port.

FerriesFerries are a form of

transport, usually a boat or ship carrying passengers and sometimes their vehicles.

Ferries are also used to transport freight and even railroad cars.

Most ferries operate on regular, frequent, return services.

A foot-passenger ferry with many stops, such as in Penang, is sometimes called a waterbus or water taxi.

Heavy Lift (LO/LO) shipsSemi-submerging are

more commonly known as a "flo/flo" for float-on/float-off.

These vessels have a long and low well deck between a forward pilot house and an aft machinery space.

Can carry oil platforms, damaged ships etc.

Tanker ShipTankers are cargo

ships for the transport of fluids, such as crude oil, petroleum products, vegetable oils and other food

The tanker sector comprises one third of the world tonnage.

Tanker sizes;Ultra Large Crude CarrierVery Large Crude CarrierMedium Sized Crude CarrierHandy-sizeAframaxPanamaxMedium Range Cross Purpose

Class Length Beam Draft

Typical Min DWT

Typical Max DWT

Seawaymax

226 m (741 ft)

24 m (79 ft)

7.92 m (26.0 ft)

10,000 DWT 60,000 DWT

Panamax

228.6 m (750 ft)

32.3 m (106 ft)

12.6 m (41 ft)

60,000 DWT 80,000 DWT

Aframax

253.0 m (830.1 ft)

44.2 m (145 ft)

11.6 m (38 ft)

80,000 DWT

120,000 DWT

Suezmax

16 m (52 ft)

120,000 DWT

200,000 DWT

VLCC (Malaccamax)

470 m (1,540 ft)

60 m (200 ft)

20 m (66 ft)

200,000 DWT

315,000 DWT

ULCC320,000 DWT

550,000 DWT

Petroleum Tankers

Combination CarrierAlso known as an Ore-

bulk-oil carrier or OBO. Ship designed to be

capable of carrying wet or dry cargoes

The idea is to reduce the number of empty (ballast) voyages, in which large ships only carry a cargo one way and return empty for another.

Gas CarrierCarriers commodities;

LNG LPG

Cruise ShipCruise ships are

passenger ships used for pleasure voyages, where the voyage itself and the ship's amenities are considered an essential part of the experience.

Cruising has become a major part of the tourism industry, with millions of passengers each year.

Tug BoatA tugboat is a boat used

for towing or pushing other vessels in harbours, over the open sea or through rivers and canals.

Also used to tow barges, disabled ships, or other equipment like towboats.

DredgerA dredger is a ship

used to excavate in shallow seas or fresh water areas with the purpose of gathering up bottom sediments and disposing of them at a different location.

Multi-purpose shipA Multi-purpose ship

(sometimes called a general cargo ship) is used to transport a variety of goods from bulk commodities to break bulk and heavy cargoes.

To provide maximum trading flexibility they are usually geared and modern examples are fitted for the carriage of containers and grains.