Ships and ship terms

Ship design and construction

Basic terms:

hull - the watertight enclosure (the actual shell) of the ship, which protects the cargo, machinery, and accommodation spaces of the ship from the weather, flooding, and structural damage
machinery - the engines required to drive the ship, as well as all the additional equipment serving the electrical installations, winches and refrigerating plant
stern - also known as the after end, is the rear (back) portion of the ship
bow - the forward part of the hull of a ship or boat, the point that is usually most forward when the vessel is underway
amidships - in or toward the part of a ship midway between bow and stern
beam - the overall width of the ship measured at the widest point of the nominal waterline
engine room - the compartment where the machinery for marine propulsion is located
propeller shaft - a shaft (long pole) that transmits power from an engine to a propeller
bow thruster - an auxiliary propulsion device at the bow of a ship to aid in manoeuvring
rudder - a device used for steering and manoeuvring a vessel
bulbous bow - a protruding (sticking out) bulb at the bow (or front) of a ship just below the waterline
hold - or cargo hold is a space for carrying cargo (load)

Examples of use:

The trimaran hull form permits the ship to carry a large capacity of weapons packages with space to land two helicopters.
An increasingly effective Union blockade reduced the availability of ships' machinery and even such items as nails and spikes.
About 60m behind the keel at the stern end, the ship is completely severed in half.
With his left hand, he gestures toward the stern of a ship at sea.
Breakers suddenly loomed up on the starboard bow, and before the ship could turn she was ashore.
Buoy line is attached at the point where the forward section of the ship has broken from the bow.
The damage from hitting the iceberg head on was at the bow rather than Amidships section to the port side is a lone sanitary area.
Themaximum beam(BMAX) is the distance between planes passing through the outer extremities of the ship.
At the far end stood a fourth watertight bulkhead, separating the crew's quarters from the engine room.
Each set consisted of one high-pressure and one low-pressure turbine driving one propeller shaft.
They have a bow thruster for manoeuvring in crowded anchorages and channels.
Rigging was certainly an important element and there are indications that stern rudders and the construction of the hull had an impact as well.
The work included extensive model testing, which resulted in the adoption of a bulbous bow that alone increased the ships' service speed by 0.5 knots.
It was found that water was leaking into the main cargo hold.

Structural members of a ship

Basic terms:

shell plating - the outer-most structure on the hull of a steel or aluminium ship or boat
strake - horizontal row of plating of the hull of a vessel
keel - the bottom-most structural member around which the hull of a ship is built
deck - a permanent covering over a compartment or a hull of a ship where the crew stand and walk on (the floor)
tank top - the top of a ship's bilge tank, usually the lowest horizontal surface on board
floor - the transverse stiffeners mounted vertically on the ship's bottom (unlike structures on land where a floor refers to something horizontal that you can stand on)
stringer - a fore-and-aft girder running along the side of a ship at the shell and also to the outboard strake of plating on any deck
buoyancy - the upward force of all the hydrostatic pressures on the hull
strength - the quality or state of being strong, firmness
stability - the ability of a ship to float in an upright position and, if inclined under action of an external force, to return to this position after the external force
bulkhead - a structure used to protect against shifting cargo and/or to separate the load
compartment - a portion of the space within a ship defined vertically between decks and horizontally between bulkheads
stem - the most forward part of a boat or ship's bow and is an extension of the keel itself
frame - in ships, frames are ribs that are transverse bolted or welded to the keel
beam -; the ship's width at its widest point
bracket - plates at the port and starboard ends, with struts that support the tank top with the bottom shell
girder - a longitudinal member used in the construction of the bottom of a ship
stern post - the upright structural member or post at the stern of a (generally wooden) ship or a boat
stiffener - one of a series of angle-bars, Z-bars, or other shapes, riveted to plating, particularly to the plating of bulkheads, to give them the necessary stiffness or rigidity

1. bulwark rail
2. bulwark stay
3. spur
4. beam knees
5. spar ceiling
6. frame
7. bilge keel
8. reverse frame
9. lightening hole in tank side bracket
10. limber boards
11. floor
12. tank top plating
13. manhole cover
14. garboard strake
15. keel plate
16. intercostal
17. margin plate
18. bilge strake
19. sheer strake
20 bulwark
21. upper deck plating
22. upper deck beam
23. centreline bulkhead
24. main deck plating
25. main deck beam

Examples of use:

The strakes were enclosed by transverse bulkheads of the same thickness.
A steel keel provides an added moment to maintain the vehicle in an upright pose.
We sat on deck until it was dark.
The water tanker version lacks the raised cargo expansion tank top amidships, and both can carry 600 tons of cargo.
In smaller ships, the plate floors themselves act as the stiffening members of the bottom shell plating.
One of the locations where stringer is mostly used is the forward part of the ship.
Flotation suits are very popular now with boat anglers and have benefits of limited buoyancy and warmth.
This suggests that I want a boat with a reserve of secondary stability and a low windage for longer trips.
At the far end stood a fourth watertight bulkhead, separating the crew's quarters from the engine room.
These might be detected by any other ships furnished with two plates dipping into the sea at stem and stern.
A frame used to support a weight is often called a truss; the stresses on the various members of a truss can be computed for any given load with greater accuracy than the intensity of stress on the various parts of a continuous structure such as a tubular girder, or the rib of an arch.
There are four cables, one on each side of the two main trusses or stiffening girders.

Ship’s equipment

Basic terms:

cargo gear - equipment used for the handling of cargo
derrick (ship's crane) - a lifting device composed at minimum of one guyed mast, as in a gin pole, which may be articulated over a load by adjusting its guys
lifting capacity - the maximum weight that can be safely lifted or carried by a person or machine
winch -; a mechanical device that is used to pull in (wind up) or let out (wind out) or otherwise adjust the tension of a rope or wire rope
shore crane - a type of large dockside gantry crane found at container terminals for loading or unloading cargo
mast - a tall spar, or arrangement of spars, erected more or less vertically on the centre-line of a ship or boat
bridge - the room or platform from which the ship can be commanded
crew accommodation - crew cabins usually located on deck 0, or below the sea level - deck A and B
life-saving apparatus - appliances that protect human life at sea
**draught - (**of a ship's hull) is the vertical distance between the waterline and the bottom of the hull (keel)
waterline - the line where the hull of a ship meets the surface of the water
freeboard - the distance from the waterline to the upper deck level, measured at the lowest point of sheer where water can enter the boat or ship
samson post - a post resting on the keelson and supporting a deck beam of a ship

Examples of use:

The handling of cargo is carried out either by the ship's own cargo gear or by shore cranes.
Derrick cranes are made of all powers, from the timber I-ton hand derrick to the steel 150-ton derrick used in shipbuilding yards.
The maximum lifting capacity is just over two tons.
The line is hauled in by a steam or electric winch, and the sounding-tube containing a sample of the bottom deposit is rapidly brought on board.
The lowest sail on a mast of a square-rigged ship.
The bridge of a vessel is the navigating centre of the ship where her course is determined.
At the head of an excellent harbour, a deep inlet about a mile long, available for ships of the deepest draught.
Waterline length was more than 13 times the depth of the hull.
Small vessels, with thin masts, light rigging & sailcloth, & a lower freeboard need less wind & smaller waves.
In the old days when it was normal to cat anchors before they were let go or on weighing, a samson post was a post erected temporarily on deck to take a tackle with a sufficiently long lead for the whole crew to man the fall.