Parts of a Ship: The Complete Guide

A ship comprise of invisible and visible structural parts made using steel and composite materials.

This guide will explore the different parts of ships found in all types of cargo vessels.

Types of Cargo Ships

There are a number of cargo vessels and means of shipping depending on sea freight cargo available.

Container Vessels

The design of these cargo ship types are for transporting freight inside containers.

They take care of majority of international dry-load shipping.

This type of ship uses gantry cranes to load and unload ISO containers.

It is presently the most popular mode of sea transport for shipping 20′, 40′ and 45′ standard containers.

You measure the carrying capacity of container ship in twenty foot equivalent unit (TEU).

A 1 TEU cargo container carries about 21,000 Kg of goods within it.

Though the size of most container used is 1x20ft, there exist also other larger and smaller container sizes.

This results in variation in actual containers numbers on the container vessel by +/- 250 cargo containers.

Bulk Vessels

The design of bulk vessels make them ideal for shipping dry cargo.

They are especially suitable for goods such as power sources including coal and ore, fertilizers, sugar, grains among other items.

They come in different sizes and designs to cater to a range of shipping requirements.

Different from other types of cargo ships that use cranes for loading and unloading, bulk vessels utilize a pump or conveyor.

These cargo vessels can carry about 200,000 DWT of load though they travel at a modestly lower speed.

Break Bulk Vessels

Breakbulk ships are ideal for transporting general cargo that otherwise needed individual loading in absence of an intermodal container.

These cargo ship types remain the backbone of sea freighting, carrying both liquid cargo and dry cargo.

They can ship cargoes such as bags of sugar, cement, or flour.

You can also use this type of cargo ship to transport palletized goods like paint, chemicals, and even timber.

Ro-Ro Vessels

Ro-Ro ships help in the transportation of wheeled freight such as excavators, trucks, buses, cars among others.

If the choice is available, you can equally employ the vessels in the carriage of certain project cargoes.

This is possible if you load the goods on mafi trailers or other wheeled modes.

There are two further classes of Ro-Ro vessels: Pure Car and Truck Carriers (PCTC) and Pure Car Carriers (PCC).

The names explicitly describe their purposes.

Multi-purpose Vessels

These type of ships are capable of shipping various cargo types all-in-one.

As hinted by the name, they are versatile vessels and utilized for several purposes.

Multipurpose vessels are the most common type of cargo ships.

This is due to the fact that they allow you to transport many types of cargo with a single vessel.

Therefore, there is no need of paying for specialty cargo vessels.

The cargo ship is particularly useful along some routes that need self-geared ships and lack shore handling facilities.

Tanker Vessels

The design of tanker vessels is specifically for transporting liquid cargo.

They are the best choice when you want to ship oil or chemicals.

Moreover, there exist crude oil carriers distinctly designed for the transportation of crude oil.

There are ultra large and very large crude oil carriers.

Conversely, chemical tanker vessels have various tanks to prevent the mixing of the different chemicals they are carrying.

Gas Carriers

These cargo vessels feature more complex technology to hold liquid gas.

They commonly fall in a similar class as oil tankers.

There are two broad categories of gas carriers which consist of Liquid Natural Gas (LNG) carrier and Liquid Petroleum Gas (LPG) carrier.

Main dissimilarity is technical because LPG carry gas at -50 degrees Celsius and 18 Kg/cm2 pressure while LNG at -170 degrees Celsius.

Moreover, LNGs are noticeable unique due to their massive spherical tanks on top of deck.

Reefer Vessel

Reefer cargo vessels have a design specifically meant for carrying cargo that you must freeze or control their temperature during shipment.

They are the best choice for transporting farm produce, some alcohol meat and fish.

Therefore, if your cargo is temperature-sensitive, then this type of cargo ship is the best selection for you.

Livestock Vessels

This a very sensitive kind of cargo vessel, because it carries live animals.

They are unique since the vessels have animals feeding zones.

Some livestock ships even have open-air corrals, though most have the corrals enclosed.

Different Parts of Ship and Their Function

Here are the basic ship parts that you need to know:

Bridge

At times referred to as a navigation bridge, it bridge represents the ship’s commanding station.

It is from here where you control the movement of ship by the help of navigational equipment.

The ship bridge controls main engine, vital deck machinery and navigation system of cargo ship.

The main functions commonly carried out in the bridge include:

• Controlling direction and speed (navigation)
• Monitoring sea conditions and weather
• Enabling internal and external communication

Monkey Island

This part of a ship refers to a kind of deck found at uppermost accessible ship height and just over the bridge.

Sometimes referred to as a flying bridge, it is an instrumental part of ship that navigation equipment such as:

• AIS Tx/Rx antennae
• VDR capsule
• Radar scanner(s) linked to radar mast
• Communication equipment gear
• Sat C/F77 Tx/Rx antennae
• Weather vane
• Several halyards attached to the yardarm for hoisting flags
• Mast leading to aft whistle of ship and navigation lights (‘Christmas Tree’)

Funnel

Also known as the stack, a funnel represents a chimney on a ship utilized to discharge boiler and engine smoke.

It helps in the safe release of exhaust gas generated inside the engine room to the external atmosphere.

This ship part allows you to easily move exhaust gas from the vessel preventing likely impedance to ship navigation.

Also, this is possible because of the inclination of the funnel toward the aft and forward movement of the marine vessel.

Bow

Bow refers to the foremost part of ship that cuts water through its edges as the vessel moves.

They are instrumental in enabling easy propulsion of ship.

There are three main types of ship bow including:

• Bulbous Bow

This is the common type of bow used in most marine vessels including cargo ships.

You can easily identify it by its unique protruding bulb-like shape just below the waterline.

• Inverted Bow

Inverted bow design has its section of bow and hull turned upside down similar to that of submarine featuring extended waterline.

• Axe Bow

This type of ship bow features vertical stem line hull construction and deep axe-like construction in front most segment of vessel.

Because of its design, axe bow helps in improving ship’s speed for similar power.

Hold

Ship hold describes the area where you keep the cargo.

In vessels that transport liquid products, the holds are in the form of tanks within which you carry the cargo.

This is why you refer to cargo ships carrying liquid as tankers.

Bow Thrusters

Bow thruster describes a propeller-like apparatus installed on both edges of ship’s bow.

It is instrumental in increasing ship maneuverability in congested waters at an extremely slow speed similar to that near ports/canals.

Accommodation

The accommodation section that houses the ship’s crews and lives.

This part of the ship features all amenities including crew cabins, offices, hospital, gym, gallery, common rooms, laundry, salon, recreation room, and laundry.

The accommodation also has a freshwater system, domestic refrigeration system, air conditioning system, garbage disposal system and sewage treatment plant.

Deck

Deck describes the floor of the hull structure of the ship.

The vessel can have several decks at different segments.

There are six main types of ship deck depending on its level and position:

• main deck
• upper deck
• weather deck
• lower deck
• poop deck
• Foredeck

Being an essential part of ship, deck carries the hull structure offering various ceiling floor to vessels.

Moreover, it gives floor and space for equipment and crew to stand and operate whilst guarding them against external weather.

Hull

The hull describes a ship’s watertight body which can be open or partly covered with deck.

It includes several watertight bulkheads and decks as the main transverse members.

Intermediate member of hull comprises of stringers, webs and girders.

Based on structural patterns, there can be longitudinal member used for reinforcement purpose.

Freeboard

Freeboard describes the distance from waterline to higher edge of deck/freeboard plating at margins of amidships.

The purpose of freeboard amongst parts a ship includes maintaining ships stability and preventing it from capsizing.

The classification society must approve minimum calculation of freeboard for the cargo ship.

Besides, the freeboard calculation serves an important purpose in defining the vessel’s load line marks.

The load line directly relates to the earning or cargo carrying capacity of the ship.

Engine Room

This is the ship’s power house found within the lowest deck aft of the vessel.

It carries essential machinery including:

• Main engine
• Fresh water generator
• Alternator (auxiliary engine)
• Air compressor
• Boiler
• Heat exchanger
• Shafting
• Purifier
• Calorifier
• Pumps
• Incinerator
• Workshop equipment among others.

The engine room serves the primary function of holding all the basic equipment and auxiliaries needed for various ship operations.

Deck House

Deck house is the part of ship represented by the house-like structure on upper deck.

Stem

This describes the foremost segment of ship’s bow.

There are two main types ship stem including plumb and raked stems.

Plumb stem is perpendicular to waterline while raked stem is inclined at a certain angle to waterline.

Stern

Stern refers to aft end structure, with its design ensuring low resistance, top propulsion efficiency and prevent vibrations.

This is the rearmost ship part which is instrumental in keeping the water out.

Typically, you will have the propellers and rudders hanged to this part of ship.

It can be have flat, sharp, tapered, or canoe-like shape to help in cutting water along its way.

Side Thrusters

Also known as tunnel thruster, side thrusters resemble a propeller and mounted on either edge of the vessel’s bow.

It assists in ship maneuvering under reduced speed in clogged waters close to canals or ports.

Side thrusters of ship affect the overall running cost of the vessel to a greater percentage.

You can power them either electrically or hydraulically.

Forecastle

This describes the foremost section of ship.

A forecastle is the foremost parts of ship.

It is part of the front section of the upper deck and does not exceed 7 percent of total length of deck.

It represents the part of ship often utilized for anchoring activity and maintaining or checking navigation lights mounted on foremast.

Deck Crane

These cranes are important parts of cargo ship and you will always find them mounted on deck.

Operated using an electric motor or at times hydraulically, deck cranes can lift up to 50 tones load.

Though not present in all ships, deck crane aid in cargo operation and cargo readjustment during shipping if necessary.

Moreover, you can equally use them for loading and unloading machinery, tools and hose from the cargo vessel.

Propeller

This is a mechanical apparatus having blades attached to a central shaft.

The blades spin, with the rotational energy transformed into pressure energy, which generates thrust needed for propulsion.

The propeller, shaft and engine together form propulsion unit.

Propeller ought to be made of materials such as aluminum, manganese, or bronze since they are outstanding corrosion-resistant.

Rudder

Rudder refers to a flat void structure contained within the aft of propeller.

It assists in steering the ship, and has steering gear system that controls the rudder movement.

Components of ship rudder comprise of rudder trunk, main rudder blade, moveable flap, rudder carrier bearing, hinge system, and links.

Further, there exist three types of rudder of ship including unbalanced type, semi-balanced type and balance type.

Rudder Pintles

This is a pin or bolt which you insert in a gudgeon to join the rudder to ship.

Modern ships utilize synthetic materials such as Teflon to make the bearings and sometimes stainless steel for liners.

Either scenario uses the water which submerges the bearing to lubricate it.

Paint Room

This is the part of ship used for handling and storing paint.

It has special features to take care of explosion and emission of chemical vapors and gases from the room.

The paint room of ship should have explosion proof lighting.

Moreover, it should have brackets to offer flexible paint handling and storage.

Emergency Generator Room

In this ship part is where you find emergency generator that supplies power for emergency loads if main electricity supply goes out.

Its location is above the uppermost deck, away from secondary and main machine and collision bulkhead.

The emergency generator features its specific switchboard within its surroundings.

It should be easy to operate and you can start it even at 0 degrees Celsius.

Ballast Tanks

These refer to compartments fabricated particularly to hold water, which is instrumental in ballasting and balancing the cargo ship.

Appropriate care should be given to ballast tanks to protect them against corrosion due to sea water.

Bunker Tanks

Bunker tank is where you store lube oils and fuel. They are separated from other parts of ship and located far from areas prone to ignition.

These is due to the fact that the tanks can catch fire easily because of their content.

Duct Keel

Duct keel describes a hollow structure comprising of two solid plates and longitudinal girder welded to create box type structure.

You will often find it in dual hull ships.

The duct keel of ship needs to offer a watertight passage through the length of vessel. It comprises of sounding pipe that helps in leakage detection.

Duct keel is a multi-purpose part of ship that performs functions including providing loads resistance, carrying oil pipes, ballast pipelines, water pipeline, among others.

Ship Cargo Gear

General cargo ships typically have deck cranes or derricks for loading and unloading of cargo without help.

Most cargo tankers dispense cargo using installed pumps and typically carry adequate cargo hose to link to receiving terminals.

Majority of tankers have cranes or derricks to lift the cargo hose.

However, most modern types of cargo ships lack capability to handle their cargoes.

They are able to load and unload the goods only with the assistance of specialized port equipment.

When mounted, ship cargo gear might comprise of traveling aerial gantry crane, rotating cranes, or derricks.

Majority of bulk carrier vessels are gearless though there are some with conveyor systems or derrick grabs for cargo handling.

Ro-Ro vessels load cargo utilizing ramps through bow, side ports, or stern.

However, in the situation of vehicles, train cars, and trailers, part of cargo gear system is vital to cargo itself.

If mounted and operable, the cargo gear part of ship can be of great importance during salvage operation.

Lightering operation is most efficient and cost-effective when carried out using the cargo gear of the ship.

Cranes and derricks installed in general cargo vessels help in loading salvage items and positioning them in their rightful place.

Overhead gantry cranes mounted on deck are specifically helpful for longitudinal shifting of weight for ground reaction, adjust trim or weight distribution.

Moreover, it is possible to shift the cranes for ease of operation.

King Post/Samson Post

It describes a heavy upright post that holds the cargo booms. Samson post sits on Keelson and holds the ship’s deck beams.

Cargo Hold

This is an enclosed area used to hold and store freight container or cargo.

Its position is below the ship deck and features holding capacity spanning from 20 to 200000 tons.

The primary function of this cargo ship part is to retain cargo during transportation.

Hatch Cover

Hatch cover is part of ship that prevents spoilage in cargo storage.

It is instrumental in making storage spaces water- and airtight, thus protecting the cargo from external conditions during voyage.

The hatch cover design changes based on the vessel type. However, it is a requirement to make it fast enough to offer quicker cargo handling operations.

Mast

Mast refers to vertical ship structure installed above bridge of ship and forward of forecastle towards bow of the vessel.

It is part of support platform for derrick and carries necessary equipment like navigation light, radars, and horn in foremast.

Moreover, the main mast of a ship also hoists the flag of vessel.

The material used to make this part of ship is high tensile steel having added rigidity depending on the derricks size it holds.

Bulkheads

These refer to vertical partition walls that subdivide the interior of ship into watertight compartments.

They minimize extent of flooding by water in the event of damage and give extra firmness to hull girder.

There are different types of bulkheads, which can be corrugated or flat including:

• After Peak Bulkhead

Bulkhead type which makes the forward margin of aft peak.

• Collision Bulkhead

This is the foremost primary transverse watertight bulkhead of ship.

It stretches from the hold bottom to forecastle deck or freeboard deck.

Its design enables collision bulkhead to restrain water from forward in the event of collision damage of bow.

• Corrugated Bulkheads

Bulkheads having corrugating plating hence doing away with the necessity for welded stiffeners.

• Engine Room Bulkhead

This refers to transverse bulkhead positioned either directly aft or forward of engine room of a ship.

• Removable/Portable Bulkhead

Steel structure utilized to separate an extended hold into partitioned sections.

• Strength Bulkhead

This type of bulkhead is a ship part that plays a role in the strength of cargo vessel.

• Swash Bulkhead

Transverse or longitudinal non-tight bulkhead fixed inside tank to minimize liquid surge when the ship pitches or rolls.

Consequently, this cargo ship part minimizes the liquid dynamic effect (sloshing forces) on surrounding structure.

A swash plate describes the plate employed for this purpose though not stretching to the tank bottom.

Girders

This describes the hollow or solid longitudinal part of a ship applied in construction of base of the cargo vessel.

There are two main types of girders of ship:

• Center Girders: Located above the keel. This is usually a single continuous piece which you must fasten to the keel using a continuous weld.
• Side girders: Spaced equivalent distances from the keel. They may be continuous or partitioned by floor segments (intercostal girders).

Girders should stretch as far as practical from forward to aft edge of the marine cargo vessel.

Keel

The keel refers to a member or sequence of members extending longitudinally that creates the structural ship base.

It normally corresponds to centerline of the vessel.

It is a key part of ship in giving longitudinal strength and effectively spreads local stresses during dry docking of ship.

The two main types of keels employed in shipbuilding are duct keel and flat keel.

Floors

These parts of ship comprise of cross members mounted at right angle to the girders and keel.

The three main types of ship floor include plate floor, solid floor and open/bracket floor.

Frames

These describe the vertical parts of ship that form the framing of upright part of ship hull.

The spacing and type of frame differ significantly based on construction of ship.

Transverse

Transverse is short form for “transverse stiffeners”, which differ from frames in 2 ways.

Unlike frames, transverses do not stretch to full compartment height.

Moreover, they have lesser thickness and strength in comparison to frames.

Depending on its position, there are three types of transverse consisting of deck transverse, inner bottom transverse and bottom transverse.

Deck Beams

These are transverse parts of ship that link the frames top ends, creating the transverse framing for ship deck.

Deck Girders

These refer to the longitudinal parts that together with the beams form the deck longitudinal framing.

Longitudinals

This is a general terminology for identifying any small longitudinal part of ship that you can use for various purposes.

The term specifically finds use in longitudinal framing.

Hull Plating

The hull plating refers to chain of steel plates that creates the watertight structure of the ship.

There are three key types of hull plating of ship comprising of:

• Deck Platingwhich describes the plate forming the primary ship deck.
• Shell Platingcreates the watertight exterior of the ship. Moreover, it counters vertical shear forces and play a role in longitudinal strength of your ship. The internal reinforcement using shell plating maybe both longitudinal and transverse.
• Bottom Plating are the parts of ship that create the watertight base of the marine vessel.

Both side shell plating and bottom plating comprise of a sequence of curved and flat steel plates butt-welded together.

‘Seams’ represent horizontal welded joints while ‘butts’ refer to vertical welded joints.

Bilge Plating

This ship part refers describes the longitudinal plating instrumental in linking bottom plating to side shell plating

Web Frames

These are oversized ship parts that substitute frame at specific locations on the cargo vessel.

Bracket

A general terminology that describes any part of ship utilized to link two members.

Beam Knee

Bracket found at the edge of deck beams which link the frame and beam to shell plating.

Pillar

Vertical members within a ship that link deck to base of ship, where you mount them between tween decks, particularly around hatches.

Pillars are quite massive and make cargo handling in holds complex.

You find these parts of ship mostly in general cargo ships for intermediate and upper deck support.

Pillars compensate for the strains due to water pressure stresses, dry docking, heavy weights and racking.

Bilge Keel

The main function of bilge keel of a ship is to aid damp the vessel’s rolling motion.

Other comparatively minor benefits of bilge keel are to enhance longitudinal strength and protection of bilge on grounding.

It is important to carefully position it on the ship to prevent extreme drag when the vessel is in motion.

Intercostal

Refers to longitudinal reinforcement part of the base structure of a ship, which binds athwartships floors together.

It is a steel girder employed as centerline intercostal in place of plate keel, stretching from forward of vessel to aft.

The alignment of side intercostal found on both sides of centerline is in appropriate space apart to ensure strength continuity.

Typically, you will have the side intercostal and centerline Centre line interspersed with auxiliary longitudinals.

However, they have smaller depth size and they make lesser strength parts of a ship.

Panting Beams

Athwartships steel members located forward of collision bulkhead, abaft the stem, in forepart of cargo ship.

The function of panting beams is to reinforce side plating of ship within the bow region to minimize in/out plates movement.

The movement of plates is due to increased pressure by sea water depth impacting the hull, as the vessel is pitching.

· Tank Side Bracket

An interlinking plate positioned between the frame and margin plate.

Its role is to reinforce the joint at the bilge turn on the path of double bottom structure.

· Panting Stringers

These describe horizontal steel plates that join the panting plates located at the edges of the ship.

· Tank Tops

The covering deck plates above double bottom structure. You will find them at the base of the cargo vessel’s holds.

They have a protective wood covering, which shields the tanks tops from heavy duty goods landed on them.

Anchoring System

Complete anchoring system of a ship comprises of:

i. Anchor

An anchor comprises of five key parts including:

• Tripping ring
• Shank
• Flute
• Crown
• Stack

A shank represents the fixed stem structure joined with flute by tripping pin going across the shank hole.

Collectively, these connecting framework together with stack form the anchor crowns.

Stack refers to a crossbar that aids in turning the anchor to help fluke go into the ground.

Fluke on the other hand is the anchor part thatdigs deep into water to keep the vessel grounded.

Anchor serves a crucial purpose in maneuvering of ship coupled with aiding in safe docking on high seas and at ports.

Anchor head gives the resistive forces instrumental in keeping the whole vessel in place.

ii. Chain Cable

Offers the weight needed to maintain the anchor horizontal while resting on seafloor or ocean bed.

iii. Chain Locker

This refers to a small section found below the windlass.

It is forward of collision bulkhead beneath main deck securing or storing anchor chain cables.

You store both aft and port anchor chains within the various locker subsections or inside starboard and port chain lockers.

Then, you fasten the chain to top structure or sides of chain locker.

iv. SpurlingPipe

This is a pipe connection to anchor windlass.

v. Hawse Pipe

The primary role of this part of ship is to lead the chain out of deck level to exterior of shell plating.

Hawse pipe construction should be sufficiently large to allow smooth running of chain in addition to providing secure anchor stowage.

vi. Anchor Lashing

The function of this part of anchor system of ship is to tightly fasten anchor if in stowed position.

vii. Windlass System

Anchor windlass assembly refers to mechanical device that assists in lowering and raising the anchor from the seafloor or ocean bed.

It incorporates a pulley system applied in moving massive weights in horizontal or vertical direction.

The key components of anchor windlass system of a ship include:

• Drum (storage)
• Drum (wrapping)
• Dog clutch
• Shaft
• Manual brake wheel
• Clutch lever
• Hydraulic brake
• Gypsy wheel
• Cable
• Gear
• Winch reel
• Anchor chain
• Control pedestrian
• Chain stopper
• Speed lever
• Riding powel
• Electric motor

Materials for Making Parts of Ship

The commonly used material for making cargo ship parts consist of:

Steel

This an exceptionally versatile shipbuilding material used extensively to make integral framework and parts of ship.

Steel is the most popular ship construction material due to its outstanding mechanical features and low cost.

However, weight of steel is one main disadvantage of using steel in shipbuilding.

For ship hull construction, you should use mild steel consisting of 0.15 to 0.23 percent carbon, and considerably high manganese content.

It is essential to keep phosphorus and sulfur contents in mild steel to a minimum (lower than 0.05 percent).

This because high phosphorus and sulfur contents affect the welding characteristics of the steel.

Moreover, cracks and the like may form easily during process of rolling when the steel has high sulfur content.

High Tensile Steels having higher strength compared to mild steel find application in more stressed locations of cargo ships.

Further, larger tankers normally use them for the bottom and deck regions.

This type of steel reduces scantlings of the ship structural parts, making it beneficial for both owner and shipbuilder.

Some of the key parts of ship made using steel comprise of:

• Main deck plating
• Bottom plating
• Thickness stringer plate
• Keel
• Sheer strake
• Longitudinal bulkheads upper strake
• Rounded gunwales
• Deck strake in the way of the longitudinal bulkheads
• Bilge strake

You can fabricate crosstrees, mast tables among other ship parts using welded steel sections and plates.

As a general rule, derrick booms consist of welded seamless tubular steel length.

Aluminum Alloys

The three main advantages of Aluminum alloys in fabrication of parts of ship over mild steel include:

i. Aluminum is lighter in comparison to mild steel and using it can save you about 60 percent of steel structure weight. For cargo ships, this is an important benefit for raising cargo carrying capacity of the vessel.

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