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
- Different Parts of Ship and Their Function
- Materials for Making Parts of Ship
- How to Prevent and Manage Corrosion of Parts of Ship
- Methods of Welding Parts of Ship
- The Best Paints for Parts of Ship
- Strains and Constraints on Parts of Ship
- Types of Cargo Vessel Construction
- Types of Cargo Transported by Ship
- Types of Containers Used on Ship
- How to Import Parts of Ship from China
- Major Container Shipping Companies
- Classification Societies for Inspection of Parts of Ship
- Ship building Companies in China
Types of Cargo Ships
There are a number of cargo vessels and means of shipping depending on sea freight cargo available.
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.
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.
Bulk break ship
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.
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.
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.
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 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.
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:
Parts of ship
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
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’)
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 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.
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 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.
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 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
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.
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 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.
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
- Heat exchanger
- 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 is the part of ship represented by the house-like structure on upper deck.
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 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.
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.
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.
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.
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 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.
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.
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.
Parts of a container ship
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 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 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.
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 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 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.
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.
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.
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.
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.
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 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.
These are transverse parts of ship that link the frames top ends, creating the transverse framing for ship deck.
These refer to the longitudinal parts that together with the beams form the deck longitudinal framing.
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.
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.
This ship part refers describes the longitudinal plating instrumental in linking bottom plating to side shell plating
These are oversized ship parts that substitute frame at specific locations on the cargo vessel.
A general terminology that describes any part of ship utilized to link two members.
Bracket found at the edge of deck beams which link the frame and beam to shell plating.
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.
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.
Parts of cargo ship
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.
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.
Complete anchoring system of a ship comprises of:
An anchor comprises of five key parts including:
- Tripping ring
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.
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
- Manual brake wheel
- Clutch lever
- Hydraulic brake
- Gypsy wheel
- 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:
Sections of cargo ship
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
- 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.
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.
ii. Aluminum features high resistance to corrosion
iii. Aluminum is a non-magnetic material and ensures low maintenance cost.
The commonly applied Aluminum alloy materials used in parts of ship are 6082 types for extrusions and 5083 for plates.
These two alloys are reliable materials in shipbuilding in addition to during manufacture.
Choosing Aluminum-Magnesium type alloys guarantee at least 10 percent reduction in costs in terms of heat-treatable.
Moreover, the outstanding corrosion characteristics of aluminum ensure ease of using them.
However, you must carefully insulate the material from adjoining steel structure.
The main disadvantage of aluminum alloys as material for ship parts is their higher initial cost.
Nevertheless, you can recover the high initial cost through increase in the cargo vessel’s earning capacity.
You can use Aluminum alloys in place of carbon steels of standard strength.
Utilizing Aluminum alloys save weight, which enhances the stability of the cargo vessel and facilitates narrower ships design.
This as a result improves fuel efficiency.
Typically, the material used to make ship propellers are copper alloys like brass.
This is because the materials for parts of materials can endure the corrosive impacts of seawater.
Copper alloys enable them to reduce cavitation.
The phenomenon takes place when propeller running under massive load forms a low pressure region.
Glass Fiber/Foam Plastics/Cork
Steel hull structure of ship makes an excellent heat conductor.
Therefore, you need some kind of insulation at the boundaries that need maintenance of desired temperature like refrigeration compartments.
You may utilize glass fiber, cork and various types of foam plastic in granulated or sheet form for insulation purposes.
It may be necessary to provide air spaces, though they are less effective.
However, modern ships commonly use glass fiber since it features many benefits over other materials for ship parts.
It has light weight, fire resistant, vermin-proof and doesn’t absorb moisture.
How to Prevent and Manage Corrosion of Parts of Ship
Corrosion is a major cause of damage on parts of ship by leading to deterioration or destruction of the various ship components.
Fortunately, the damage is manageable if you understand ways of preventing and controlling corrosion of ship parts.
Here are some of the methods of preventing and managing corrosion of parts of ship:
Parts of container ship
Application of coatings to ship parts prone to corrosion is among the most effective techniques of preventing and managing ship corrosion.
It is advisable to apply suitable coatings to parts greatly exposed to damaging seawaters.
You can apply a vinyl tar and two-part coal-tar epoxy coat to the hull of ship to protect it from destructive minerals and salts.
Being equally prone to corrosion, repainting of deck can aid in remedying the damage.
Nonetheless, it is best to apply chlorinated and alkyd rubber coating to guarantee protection from saltwater and day-to-day wear and tear.
Corrosion also happens in cargo tankers when water and sulfur in crude oil combines with water vapor.
Furthermore, microbes can as well break down the protective coating of tanks.
Therefore, it is important to apply modern coating techniques to protect the integrity of part of ship.
Use the Correct Materials
Corrosion can lead to severe damage based on material used in shipbuilding.
The level of corrosion differs depending on the type of material used.
Therefore, metal type is an important consideration when fabricating and replacing parts of ship.
Plastic and stainless steel exhibit higher resistance to corrosion compared to other materials used in fabrication of ship parts.
Moreover, certain titanium alloys and nickel alloys properties specifically engineered for corrosion prevention.
This makes them perfect for ensuring maximum protection and durability of the parts of ship.
Follow Proper Maintenance Procedure
With the right maintenance procedure, there are less chances of your parts of ship experiencing corrosion.
This allows you to notice any early damage signs and take necessary steps to remedy the problem before escalation of damage extent.
Nevertheless, this can imply additional costs, though you can find cost-effective solution by outsourcing maintenance.
Protect Electrical Circuits
Maintaining your cargo ship’s electrical circuitry dry can as well aid in preventing and controlling corrosion on parts of ship.
You can do this by utilizing waterproof insulation about cable connectors.
Moreover, it is equally advisable to use electrical bonding.
This technique entails linking all underwater metallic ship parts together using bonding strips or wires.
The linkage puts them to similar potential, thus preventing corrosion as a result of stray currents.
Methods of Welding Parts of Ship
You select technique of welding parts of cargo ship depending on production rates, customer specifications, and a number of operating constraints.
Here are the common techniques used in welding ship parts:
Electric Arc Welding
In this method, you create a circuit between the metal part of ship and a wire or electrode.
When you hold the wire/electrode a short distance from the part, you create a high-temperature arc.
This arc produces enough heat to cause the work-piece edges and tip of wire or electrode to melt creating a fusion-welding system.
There are several categories of electric arc welding appropriate for application in shipbuilding.
All the processes need weld area shielding from the atmosphere.
You may subdivide the electric arc welding process into gas-shielded and flux-shielded process.
Gas welding applies heat produced through combustion of gas fuel and often utilizes a filler rod for metal deposited.
The most popular fuel is acetylene, employed in conjunction with oxygen, commonly referred to as oxyacetylene gas welding.
Hand-held torch points the flame to ship part you are welding while concurrently melting filler metal that gets cast on the joint.
The part of ship surface melts to create molten puddle and you fill the grooves or gaps with the filler material.
Besides, the molten metal, particularly filler material, solidifies while the torch moves across the work-piece.
Gas welding is relatively slow and not appropriate for application with semiautomatic or automatic equipment.
As a result, it is seldom utilized for ordinary production welding of parts of ship.
Brazing and Soldering
These are methods of bonding 2 metal parts of cargo ship without melting primary metal.
In the techniques, you make a fluid to flow in and cover the gap between the 2 surfaces and eventually solidify.
If the filler metal temperature is below 450 degrees Celsius, you refer to the process as soldering.
Conversely, when the temperature is over 450 degrees Celsius, you refer to the process as brazing.
Usually, you perform soldering of parts of ship applying heat from flame, soldering iron, electrical induction or resistance.
Similarly, brazing employs heat from electrical induction/resistance, or flame. You can as well carry out brazing by immersing ship parts in a bath.
Nevertheless, brazed and soldered joints do not display the strength features of welded joints.
Therefore, soldering and brazing find minimal application in ship construction and repair.
The welding technique transfer heat via molten slag that melts the filler metal and work-piece.
Electoslag welding uses the same equipment as electric arc welding.
However, the process maintain the slag in molten state due to its resistance to current flowing between the work-piece and electrode.
For this reason, it is an electric resistance welding process.
The ship part welding method is effective for automatically forming vertical butt welds.
Moreover, it is greatly suitable for thicker plate.
This process of welding parts of ship applies ultra-heated liquid melting for melting the part and filler metal.
The process produces the liquid metal due to chemical reaction between Aluminum and a metal oxide.
You pour the liquid metal into the cavity you want to weld, then surround the cavity with a sand mold.
Similar to casting, thermite welding is mainly instrumental in repairing forgings and castings to weld large parts of ship like stern frame.
In this welding technique, laser beam aid in melting and joining the parts of ship.
However, the high cost of laser welding is impeding its commercial application in shipbuilding.
Electron Beam Welding
This is another comparatively new method of welding parts of ship.
You make the weld by shooting an electrons stream via an aperture to the part, enclosed using an inert gas.
The welding technique does not rely on the material thermal conductivity to cause the metal to melt.
This makes electron beam welding advantageous due to decreased metallurgical effects and lower energy requirements.
However, similar to laser welding, the main disadvantage of electron beam welding technique is high cost.
Stud welding of ship parts refers to a type of electric arc welding, where the stud is the electrode.
The stud welding gun grips the stud whilst you form the arc and the stud end and plate get molten.
The gun then presses the stud onto the plate, leading to welding of the stud to the plate.
You achieve shielding by utilizing a ceramic ferrule enclosing the stud.
It is a semi-automatic welding process often applied in shipbuilding to enable fixing of non-metallic materials, like insulation onto steel surfaces.
The Best Paints for Parts of Ship
Ship maintenance requires that you regularly paint the parts of ship to prevent corrosion and offer resistance to additional natural elements.
Paints for ship parts comprise of a pigment diffused in a liquid known as the ‘vehicle’.
The pigment disperses out thinly and with time the vehicle transforms to create a sticky dry film.
Paints which prevent corrosion of steel parts of a ship consist of these vehicle types:
a) Pitch or Bitumen solutions which you can find as white spirit or naphtha solvent.
b) Oil-based: The primary constituent of these are vegetable drying oils like tung oil and linseed oil. Addition of driers help in accelerating drying through natural reaction between the paint and oxygen.
c) Oleo-resin: The vehicle comprise of artificial or natural resins included in drying oils. Certain resins might react with oil to provide a quicker drying vehicle.
Other resin types are non-reactive with the oil.
You apply heat to initiate resin dissolution and result in sticking of oil to the part of part you are painting.
d) Alkyd resin:The vehicles offer shorter drying period and enhanced film forming characteristics of drying oils. There manufacturing may not be from oil, since you can use an oil-free acid or oil fatty acid.
Vehicle types (b) and (d) are not ideal for underwater painting, and only sometypes of (c) are appropriate for such painting.
e) Chemical-resistant: these vehicle types exhibit high resistance to extreme exposure conditions. The vehicles in this category consist of: Epoxy/coal tar resin, epoxy resins Chemicals, Vinyl resins, polyurethane resins, Zinc-rich paints, isomerized and chlorinated rubber.
f) Anti-fouling paints: Commonly referred to as bottom paints, are underwater hull paints that are specialized coatings. You apply them to facilitate detachment and/or slow growth of subaquatic organisms which attach to ship’s hull, affecting its performance and longevity.
The commonly used compounds in anti-fouling paints include biocides and copper oxides.
Furthermore, you can as well use silicone and Teflon coatings.
These hard bottom paint types are very slippery to enable adherence of growth.
Strains and Constraints on Parts of Ship
· Static Strains
You determine these strains on parts of ship when the cargo vessel is moving.
Poor longitudinal mass distribution is often the main cause of the stresses.
The distribution of forces may not be uniform through the entire length of the vessel.
This happens even when you have the vessel’s overall weight balanced by total buoyancy forces.
This takes place when there is concentration of forces of buoyancy about region amidships while there is load at the ends.
The vessel will incline to go downwards at the stern and bow whilst the region amidships will incline to shift upwards.
The situation will subject parts of ship in deck structure to tensile strain while base structure will be under compressive strain.
You can compare the situation to a beam having support in the middle while bearing load at the ends.
Sagging happens if there is buoyancy forces concentration below stern and bow of cargo vessel, whilst there is load at section amidships.
The ship tends to shift upwards at the edges and trough amidships.
Here, ship parts in deck structure experience compressive strain while the base structure is under tensile strain.
The phenomenon is comparable to a beam supported from both edges with load at the center.
· Dynamic Strains
Certain situations develop extra stresses when the cargo vessel is under way.
The primary cause of dynamic stress on parts of a ship is waves effect on the ship hull in turbulent waters.
Here are the two main causes of dynamic strains and constraints:
A ship pitches during voyage in heavy seas.
There is possibility of the bow rising over a wave crest and emerging fully out of water.
If it falls back on water, the bow can experience a major impact referred to as pounding.
Therefore, it is essential to reinforce the hull plating found at the bow to prevent curving of the plating.
The strain can as well happen at the stern of the ship, though to a lower extent.
When waves pound the stern and bow of a cargo vessel, they lead to pressure variations.
The variations in pressure tend to cause in and out movement of the plating, a phenomenon known as panting.
Therefore, it is important to strengthen the framing part of ship to avoid exaggerated hull plating movement.
Types of Cargo Vessel Construction
Some of the main cargo vessel construction include:
You use this type of framing for ships having lengths lower than 120m.
The beams, frames and floors create rings arranged closely together.
- The parts of ship that provide longitudinal strength in transverse framing of shipbuilding are:
- Side girders
- Center girder
- Deck girders
- Side shell plating and deck
- Entire bottom
- Tank top
Transverse framing makes sure there is sufficient cross sectional strength able to withstand rolling, vertical loads, dry docking and overall stresses.
Nonetheless, sheer stresses may result in distortions between the rings.
Longitudinal framing is a must for very big cargo ships, including bulk-ore carriers and oil tankers.
Deck beams, wed frames that substitute the frames, and floors form the rings.
The rings spacing is farther apart compared to transverse spacing.
The parts of ship that form the longitudinal strengthening members consist of:
- Deck girders
- Large number of bottom, side and deck longitudinals, which are thin though are several of them.
This type of ship construction blends transverse and longitudinal framing.
You apply one framing type in a specific part of ship, while the other type in another section.
The most popular blend is using transverse framing for sides and longitudinal framing type for the deck and bottoms.
Types of Cargo Transported by Ship
Here are the main types of goods you can transport using cargo ships:
a) General Cargo
This cargo type consists majorly of 2 categories:
These describe goods that you must load individually onto the vessel.
You cannot ship them in bulk as the case with grain or oil, nor in intermodal shipping containers.
All packed items in drums, crates, boxes, bags, barrels and refrigerated goods like canned meat and fruits fall in this class.
Moreover, you can as well use unit loads of goods fastened on a skid or pallet.
The type of vessels used to transport these types of goods are general cargo ships.
These consist of prepackaged goods that you count during loading and unloading.
Types of neo-bulk goods comprise of cars, waste paper, bananas, scrap iron, bundled steel, lumber, cars, and heavy machinery.
It is essential to note that not only cargo specific gravity determines the stowage factor, but also employed type of packaging technique.
b) Bulk Cargo
These refer to liquid or solid bulk goods shipped unpackaged in large amounts.
The two main subcategories of bulk cargoes include:
Dry Bulk Cargoes
They describe large quantities of loose solid goods that you pour straight into storage part of a ship.
Types of dry bulk cargoes include cement, ore, coal and grains like wheat.
Liquid Bulk Cargoes
These bulk cargo types refer to large quantities that you transport in specially constructed vessels like tanker ships.
There exist a wide range of liquid bulk goods consisting of:
- Citrus juice
- Fresh water
- Chemicals such as chlorine, styrene monomer, and ammonia
- Hydrocarbon products like liquefied natural gas (LNG) and liquefied petroleum gas (LPG).
This describes goods transported utilizing intermodal containers.
Also known as ISO containers, they feature standardized dimensions.
You can load, unload, stack and transport container cargo efficiently over long distance.
Moreover, it is possible to transfer containers from one transport mode to another without opening them.
Container cargoes have totally mechanized handling system, allowing you to handle them using special forklift trucks and cranes.
All containers have numbering and you can track them using computerized systems.
d) Ro-Ro Cargo
Roll-on/Roll-off goods refer to wheeled cargo, like railroad cars, trailers, semi-trailer trucks, trucks and cars.
You load and unload them by driving the cargo on and off the vessel utilizing a platform vehicle or on their wheels.
These refer to perishable goods which need temperature-controlled shipping.
They comprise of dairy products, fish, fruit, vegetables, meat and other foods.
Types of Containers Used on Ship
Let’s look at the different container types used in shipping of cargo:
Types of shipping containers
Dry Cargo Container
This is the most popular shipping container utilized in transportation of dry cargo.
They are totally airtight which makes them completely sealed until you open them at destination port.
Dry cargo containers come in various sizes from 10, 20, and 40 TEU carrying capacity.
They are the most elementary container types lacking facilities like ventilation, humidity and temperature control and able to open from both sides.
Open Top Containers
This refers to type of dry cargo container that you can access both from top and front.
It is possible to completely remove or convert their top depending on specific requirement, enabling easy access to load or unload cargo.
They are ideal for transportation of heavy duty machines, over-height cargo, overweight cargo and industrial goods.
Open top containers are the only shipping container that can carry cargo lacking a fixed height.
This makes it appropriate for goods which do not fit perfectly in standard containers.
Flat Rack Containers
Cargo container of this type is mainly fit for shipping of heavy machinery, industrial tools, heavy cargoes, oversized goods, and large accessories.
It features collapsible sides, open top and a sturdy metal plate at the base to bear heavy loads.
Since heavy cargoes commonly require lifting cranes, the open top facilitates easy loading and unloading.
However, this exposes the cargo to weather that can lead to damage, thus the necessity for special attention.
Ventilated Cargo Containers
These are container types having ventilations at the bottom and top of their sides that allow passage of air.
However, the ventilations are capable to prevent ingression of water.
The containers are therefore special since they prevent temperature rise or humidity surge by allowing flow of cool and hot air.
This flow of air inhibits condensation, thus making them ideal for shipping food crops like coffee beans and additional organic products.
Tunnels And Open Side Cargo Containers
Tunnel containers enable you to access the cargo inside from both edges of the shipping container.
This permits wider operating area and better accessibility.
Moreover, open side container features large doors that open on a single side.
These features allow seamless and quick loading and unloading of cargo; hence saving money and time.
Double Door Containers
This type of cargo container has access on either sides, making it possible handle goods from both sides.
The two doors enables you to load and unload bulky complex cargo, including construction materials.
Furthermore, double door container allows locking and merging with other cargo containers.
This facilitates flexibility during cargo handling.
Car Carrier Containers
This is a special type of shipping container purposely designed for transporting cars and motor vehicle in general.
The capacity of car carrier container are 20 and 40 TEU, appropriate when shipping low number of vehicles.
Refrigerated Cargo Containers
These container types are essential in the shipping of live cargo including vegetables, fruits, meat, and fish.
These types of cargo usually require controlled temperatures.
Furthermore, you can as well use them to transporting essential drugs supplies requiring fixed temperature conditions.
The containers have in-built refrigeration system and are efficient and easy to manage.
They are capable of running in the temperature range from -25-25 degrees Celsius.
How to Import Parts of Ship from China
Parts of ship
Identify Ship Parts to Import
It is essential to collect all the relevant information about the parts of ship you intend to ship from China.
Get descriptive literature, parts compositions information and if practical, product samples.
This information will be instrumental when determining the tariff classification.
To establish the duty rate applicable to your cargo, you will need the HS Code (tariff clarification number).
Make Sure there Exist no Import Barriers on the Ship Parts
Always ensure that the parts of ship you plan to ship from China have noimport barriers to avoid inconveniences.
Some of the barriers could be carrier restrictions, high customs duties, and/or failure to comply with relevant safety and quality standards.
Find a Parts of Ship Supplier in China
After settling on the ship parts, finding a reliable supplier will be the next step.
Though the common supplier marketplace for most buyers is Alibaba, there are several other options that you can find through Google search.
Nevertheless, it is vital to remember that the supplier on Alibaba possibly is not the manufacturer of parts of ship.
There are high chances of them being a trading company or wholesaler.
Determine Products Landed Cost
Calculating the landed cost helps you determine your bottom line.
The cost includes the overall cost of the parts of ship from factory floor to your door.
It includes cost of ship parts, insurance, customs and shipping.
These is a significant factor that helps you establish whether it is economical to import the parts of ship from China.
Prepare Your Shipment
It is advisable to start making freight shipping arrangements a fortnight before the products are ready for shipment.
Finding a freight forwarder is the first step of shipment preparation.
Always make sure to get freight quote from more than one forwarder even when you already have a trusted freight forwarder.
This allows you to do comparison ensuring that you land the best deal.
After accepting the quotation, request the forwarder to furnish you with the policy copy.
This will come in handy in case you will need to file a claim.
Requesting this document makes sure that your freight forwarder does not fail to book insurance.
Track the Cargo
Shipping of parts of ship from China takes time.
Typically, you will get an arrival notification within five days or lower of port arrival.
The notice comes from the destination agent registered on the B/L.
Obtain your Shipment
After the arrival of your cargo, engage your customs brokers to help in the clearance of the goods through customs.
Major Container Shipping Companies
Here are the largest shipping companies in the world:
- China Ocean Shipping Company ( COSCO)
- A.P. Moller – The Maersk Group
- The CMA CGM Group
- The Mediterranean Shipping Company (MSC)
- The Yang Ming Marine Transport Corporation
- Ocean Network Express(ONE)
- Pacific International Line(P.I.L)
- Hyundai Merchant Marine
- Evergreen Lines
Classification Societies for Inspection of Parts of Ship
There are several classification societies for initial and continuous inspection of cargo ships and parts of ship.
They are renowned and dependable organizations which evaluate and maintain the seaworthiness of a ship and give them classification.
Here are some of the internationally recognized Classification Societies:
- Nippon KaijiKyokai (Japan)
- RegistroItalianoNavale (Italy)
- Russian Register of Shipping (Russia)
- Germanischer (Germany)
- Det Norske Veritas (Lloyd Norway)
- Bureau Veritas (France)
- American Bureau of Shipping (United States of America)
- Lloyd’s Register of Shipping (Great Britain)
They publish laws and regulations related to provision of sufficient equipment, reliability of machinery utilized on board, strength of parts of ship, etc.
You can build the cargo ship in any country and you are not limited to only relevant Classification Society of that country.
The shipbuilding can adhere to rules and regulations in compliance to any specific classification society.
Ship building Companies in China
The main ship construction yards in China include the following:
- China State Shipbuilding Corporation (CSSC)
- China Shipbuilding Industry Corporation (CSIC)
- Fujian Shipbuilding Industry Group Corporation (FSGIC)
- COSCO Shipyard Group
- Afai Southern CIC Shipyard(Panyu Guangzhou) Ltd.
- China’s Shipping Industry Company (CIC)
- TSUNEISHI GROUP (ZHOUSHAN) SHIIPBUILDING INC.
- PaxOcean Engineering Zhuhai Co China
- China Shipbuilding Trading Corporation (CSTC)
- Dalian ShipbuildingIndustry Co., Ltd.
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