Ship Terminology

[Guest]

G

Galley: The kitchen!

Gallows: A U shaped beam on the deck of a trawler through which the trawl warp is fed.

Gangway: A ramp or steps used for embarking or disembarking the vessel.

Garboard Strake: The strake on either side of the keel plate.

General Arrangement Plan: A plan of the vessel showing the layout of machinery and all space arrangements.

Gill Jet Thruster: A thruster unit using a vertical axis propeller in a transverse tunnel. Water is drawn from both sides and is discharged through the bottom of the hull. Rotating gill fins then direct the water flow into one of a number of indexed positions around the discharge thus creating a thruster unit capable of directing the thrust through 360 Degrees.

Gimbals: Two rings, pivoted at right angles to each other that allow a compass mounted in the centre complete freedom of movement to maintain in the horizontal plane.

Gin Block: A single pulley block in a, usually fabricated and simple, frame.

Gipsy: A slotted wheel or cable holder mounted on the horizontal shaft of the windlass for heaving up the anchor cable.

Girding: A term referring to a tug that has been capsized by the vessel under tow, usually as a result of allowing the tow to become at right angles to the tug.

GM: The metacentric height of a vessel and has a direct bearing on the stability of the vessel. It is actually the vertical distance between the metacentre (M) and the centre of gravity (G). To be stable G must always be below M.

Goal Post Mast: Seen on cargo ships a mast arrangement with two vertical masts and a cross member arranged in a transverse line. Used to support more than one derrick.

Gog Rope: A short rope used in towing to position the main tow rope on the tug in an attempt to prevent the tow becoming at 90 degrees to the tug and hence Girding.

Graving Dock: The traditional type of Dry Dock, which is dug out of the ground and has watertight gates at one end. The vessel enters, the gates are closed and the dock is pumped out until the vessel rests on the blocks.

Grim Wheel: A contra rotating free wheeling vanes blade fitted behind a propeller blade, which is supposed to reclaim some of the energy lost in the propellers slipstream. It is slightly bigger than the main propeller and rotates slower. These were actually fitted to the QE2 in the 80’s but fell off during a transatlantic crossing!

Gripes: Wire ropes used to secure a lifeboat in the davits and prevent it from swinging out.

Gross Registered Tonnage: The capacity in cubic feet of the spaces within the hull and enclosed spaces above the main deck available for cargo, passengers, stores fuel, crew etc., divided by 100. Hence 100 cubic feet equals 1 Gross Ton.

Gunwhale: Sometimes pronounced as gunnal, It is the upper edge of the hull above next to the bulwark.

Gusset Plate: A fillet bracket plate fitted in a horizontal plane between two adjacent vertical plates.

[Guest]

have you ever seen a girding??

that must be quite scary!

[Guest]

I haven't seen one but I have been on a ship in the past whose claim to fame was dropping an anchor right through the middle of a tug. That must have been worth watching.

I have also been on a ship that was pumping waste water into a barge tied up alongside with a very small tug tied up to that. The barge wasn't quite as compartmentalised as it should have been so the free surface effect caused it to sink, taking the tug down with it. That was worth watching.

[Guest]

H

Half Breadth: Half the breadth of a ship. At any transverse section half breadth distances could be used as the vessel is symmetrical about the keel.

Hard Patch: A plate welded or riveted over a hole to repair the original.

Hatch Beam: Removable beam fitted over a hatch opening, usually supporting a wooden or steel hatch cover.

Hatch Coaming: Vertical plating surrounding a hatch opening to prevent the ingress of water into the hatch after waves have broached the deck. The hatch covers will rest on, and be secured to, the top edge of the coaming.

Hatch Cover: The watertight covering for a hatch opening, secured to the top of the coaming. Covers could be either loose boards, as in old coasters, folded and chained on rollers, as in more modern general cargo, or solid one piece, as in container ships.

Hatches: The opening in the decks of a cargo vessel through which cargo is loaded and discharged.

Hawse Pipe: A pipe fitted between the Foc’s’le and the bow plating through which the anchor cable passes.

Hawser: A wire or hemp rope used for mooring, towing etc.

Headfast: A mooring line taken from the bow and led forward. Also known as a headline or headrope.

Heave To: A manoeuvre to bring the vessel to rest but facing into the weather. Sometimes done in extreme weather to minimize damage to a ship. Usually occurs slightly before heaving up!

Heaving: Vertical linerar movement of the vessel.

Heavy Lift Derrick: Large cargo handling crane, usually attached to one of the main masts and originally operated by a steam winch.

Heel: The angle in a transverse arc from vertical.

Heel Block: The pulley block found at the lower end of a derrick boom.

Helm: The entire steering mechanism of the vessel.

Helmsman: The crewmember who operates the steering gear.

High Seas: Areas of water that are outside the jurisdiction of any country or state.

Hogging: A condition of the hull where the extremities are sat lower in the water than the center section. The opposite of sagging.

Hold: A volume within the hull section, which is arranged for the stowage of cargo. Separated from other compartments by bulkheads and possibly including “Tween Decks”.

Homogenous Cargo: Entire cargo of the same type such as found in oil tankers, bulk carriers, gas tankers etc.

Horn: The part of the stern frame casting from which a spade rudder is hung.

Housing: The portion of a mast found below the line of the main deck.

Hunting Gear: The system of rods and linkages that provides positional feedback to the steering gear variable delivery pump of the position of the rudder.

Hydraulic Winch: A cargo or mooring winch whose motive power is provided by a hydraulic system. A centrally located hydraulic system can be used to operate a number of winches around the vessel.

Hydrofoil: Is simply a wing that is designed to operate in water. These include the wings used to generate lift and elevate a hydrofoil craft above the water and stabilizer fins found mainly on passenger vessels.

[Guest]

I

Ice Breaker: A vessel specifically strengthened to enable ice to be broken with the bow. Generally vessels will not have sufficient power to enable this to be done continuously in thick ice so the ship is designed to go ahead and astern quickly. The ship will ride up onto the ice and the weight of the vessel will break the ice. The vessel will then go astern to give sufficient room to gain enough speed to ride up on the ice again. Ice breakers usually have very substantial bows, sometimes actually filled with concrete and a large skeg behind the rudder to protect it when the vessel is going astern into the broken ice.

Immersion: This is the weight required by a vessel to either increase or decrease the mean draught by 1 cm. Quoted in Tonnes per cm or TPC.

Inboard: In the direction of the vessel towards the center line.

Inclination Test: Also known as the Inclining Experiment this determines the position of the vessels center of gravity. It will always be done when a ship has been completed in the yard and is usually repeated after significant work has been done such as in dry docks. It basically consists of moving large masses in a transverse manner on the ship and measuring the respective angles of heel. This information is then used to calculate the position of the center of gravity.

Intercostal: Is a longitudinal girder fitted between the floors and the frames of a ships structure but are not necessarily continuous.

Isherwood System: A method of ship construction that utilizes mainly longitudinal frames and stiffeners.

[Guest]

i think this should be made sticky...what you think john??

[Guest]

J

Jack Staff: The flag staff fitted at the bow.

Jack Stay: Tensioned ropes or wires to support such items as davits or masts.

Jack: Lifting device with high mechanical advantage either from a screw lifting device or hydraulic piston.

Jacobs Ladder: Rope ladder hanging over a vessels side. Used for embarking or disembarking while the vessel is at anchor or for use by pilots joining or leaving the ship.

Jetsam: Goods or items that have been discarded overboard whilst at sea. Although traditionally common this practice is now strictly controlled by internationally agreed legislation.

Jib: A projecting arm of either a crane or a derrick.

Joggle Plate: A hull plate that is shaped to enable it’s longitudinal edge to overlap the adjacent plate.

Joggle Shackle: A cable shackle with a quick release pin used in anchoring to haul on one cable when mooring with two anchors.

Jumper Stay: A rope or wire fitted horizontally from one mast to another or any other fixed point.

[Guest]

JJib: A projecting arm of either a crane or a derrick.

Isnt this also the forward sheet on sailing vessles or am i totally off the mark here?

(richard i agree, great reading and should be sticky as its invalubale)

[Guest]

Hi Squiffy,

I am going to stick my neck on the line here and get shot to pieces but I think the sailing "Jib" is so called because it is supported by a jib, similarly named because of the mast but the sail itself is called the "Jib Sheet".

OK guys feel free to jump in......

[Guest]

I thought Jib was a chat up line used by sailors...

like...erm...... "I like the cut of your jib...saucy boy!

[Guest]

There you have the advantage of me Terry.

I have never had the need to use such phraseology but you have obviously come across it before......? maybe in one of the bars you wear the sequined dress.....?

[Guest]

There you have the advantage of me Terry. I have never had the need to use such phraseology but you have obviously come across it before......? maybe in one of the bars you wear the sequined dress.....?

LOL! Sounds right to me, ive always called them jibs, and normally the jib is held to the mast via a rope from the mask to the bow and then secure with a rope/cleet arrangement forward?

[Guest]

I think so, Jib Sail, Jib's'le, Jib Sheet all refer to the same.

[Guest]

K

Kedge Anchor: One or more anchors carried in addition to the main forward anchors, usually stowed aft. Can be carried by an anchor handling vessel and then used to winch a vessel off from aground or to hold a vessel against a tide.

Keel Blocks: Heavy blocks made of wood and concrete that a vessel sits on in dry dock.

Keel Plate: The center strake of bottom plating.

Keel: The main structural longitudinal member running the length of the vessels bottom.

Keelson: A longitudinal girder on each side of the centerline.

Kent Ledge: Permanent ballast usually of iron. Can be found in the flat bottom of vessels to improve stability.

King Post: A vertical post fitted to support a derrick. Also referred to as a Samson Post.

Kitchen Rudder: A means of directing flow over a propeller to give ahead or astern thrust. Two curved plates form a shroud around the rudder which can be rotated to be either parallel to the propeller, allowing forward thrust or closing around the back of the propeller to redirect the thrust into an astern direction. Works exactly the same as the devices fitted to some modern jets to redirect thrust forwards for braking after landing.

Knee: A structural component fashioned into a right angle to provide strength and support at a joint such as a deck beam to a side frame specifically known as a Beam Knee.

Knuckle: Is generally regarded as a sudden change in the direction of hull plating.

Kort Nozzle: A shroud surrounding a propeller, which has the effect of reducing slip in the water flow and greatly improves propeller efficiency. Found in such vessels as tugs where the slip is considerable when under tow.

[Guest]

L



Labouring: The action of a vessel slowly pitching and rolling in bad weather and making little headway on course.

Lashings: All wires, ropes and chains used to secure cargo’s. Nothing to do with gravy.

Leading Block: A type of rope block used to guide and change direction of a rope usually into a Capstan.

League: Nautical measure (As in 20,000 of them!), which equals 1/20th a degree of latitude or three miles.

Lee: The sheltered side of an object which can refer to either a vessel, building or a land mass.

Leeward: On the sheltered side of a vessel.

Length Between Perpendiculars, LBP: The distance along the Summer Load Line between the forward and aft perpendiculars. The forward one is at the point where the stem cuts the waterline and the aft one is where the aft side of the rudder post or rudder stock cuts the same. Often referred to as a ships length.

Length Overall, LOA: The total length of the vessel including any extremities. There can be a significant difference in LBP and LOA on sailing vessels.

Light Displacement: The weight of the unladen vessel, measured in tonnes. The difference between the Loaded Displacement and the Light Displacement is the Deadweight.

Lightening Hole: A hole cut into any form of plate that is designed to reduce weight without sacrificing strength.

Lighter: A flat bottomed, unpowered craft for the transport of goods and cargo to and from a vessel.

Lignum Vitae: One of the very few woods that is actually denser than water. This wood was traditionally used as a stern tube and stern frame bearing material in old water lubricated bearings. This was superseded by the advent of oil filled stern tubes with stern seals but, strangely enough, the circle has turned and vessels are now using a plastic bearing material and returning to water cooled and lubricated bearings.

Load Line: A number of lines painted on the side of the vessel at the midship section which indicate the minimum allowed freeboard in a number of conditions and world wide locations. Also known as the Plimsol line and incorporates lines for the following:

Summer Load Line

Winter Load Line

Winter North Atlantic Load Line

Fresh Water Load Line

Tropical Fresh Water Load Line

Loaded Displacement: The weight in Tonnes of a vessels hull, machinery , spares, cargo, fuel, water and crew when a ship is immersed to its Summer load line.

Locking Pintle: A Rudder pintle specifically designed with a restraining collar to prevent the rudder from displacement in, for instance, heavy seas.

Loll: Also known as the Angle of Loll occurs if the centre of gravity is allowed to become above the centre of buoyancy. The vessel will “Loll” over until the centre of gravity is in line with the centre of buoyancy. If, by design, or cargo loading this cannot happen the vessel will simply capsize. Particularly significant with such things as a ships crane when the centre of gravity will instantly move upwards when a weight is lifted from a hold. The centre of gravity of the mass will shift from the bottom of the hold to the tip of the jib in the time it takes the crane to take the weight of the load.

Longitudinal Bulkhead: A bulkhead that runs from forward to aft as opposed to transversely which is across the vessel.

Luff: Opposite to Lee so it is the windward side of a vessel, building or land mass.

Luffing: Is the vertical movement of the jib of a crane, hence a “Luffing” crane is one whose jib can be moved vertically, as opposed to a “Chuffing” crane which is one that won’t move at all.