Ship Terminology - Page 2

adzam · 16-04-2006

Excellent stuff BB

really appreciated

Adz..

**Bunkerbarge** · 16-04-2006

I am taking these from a book which is a glossary of Maritime Technology.

I am extracting just the ship construction items and elaborating on the basic definition with a bit of my own wording.

I'm glad you like it as I didn't think it was going to be anywhere near as time consuming as it is!!!

**Bunkerbarge** · 17-04-2006

E

Effective Length: Ships length that is used for speed-power calculations and the coefficients relating thereto.
Effective Power: Power required to tow a ship and is a product of the total resistance and speed of the hull.
Elastohydrodynamic: A regime of lubrication where concentrated sliding or rolling contacts are separated by a full film of oil. The thickness of the film depends on the viscosity of the oil and the elastic properties of the solids. Not really a ship nomenclature term but I just like the word and thought I would throw it in!
Even Keel: A condition where the fore and aft draughts are equal and the keel is parallel to the waterline.
Extreme Breadth: The maximum breadth over the extreme points Port and Starboard of a ship.
Extreme Depth: Depth of the ship from the upper deck to the underside of the keel.
Extreme Draught: Distance from the waterline to the underside of the keel.

**wonwinglo** · 17-04-2006

Excellent Richard,at long last a glossary of terms for reference.

**Bunkerbarge** · 18-04-2006

F

Factor of Subdivision: Value used in the calculation of the permissible floodable length of a compartment with respect to the damage stability of a ship. The value is determined by a formula, which depends on the length of the ship and is measured by a criterion of service numeral. (A numeral based on the relation between the volume of space allotted to passengers and machinery and the total volume).
Fair: Term applied to the readjustment of ships plating that has become slightly buckled in a collision.
Fairlead: Fitting allowing ropes and mooring lines to go in the required direction unobstructed. Usually fitted in a gunwhale or ships rail at the foc’s’le or stern to facilitate a smooth entry of the mooring lines.
Falls: Rope and blocks attached to the davits for raising and lowering lifeboats.
Fashion Plate: Side plate at the end of the superstructure deck, generally with a curved end.
Fathom: Measurement of the depth of water and equal to 6 feet.
Feathering: 1) Positioning of the blades of a Controllable Pitch Propeller such that no thrust is generated, exactly the same as an aircraft propeller. 2) The release of small quantities of steam by a boiler safety valve as it approaches lift pressure.
Feed Tank: Storage tank for boiler feed water, usually a double bottom tank.
Feeder Ship: A smaller vessel that transfers cargoes from deep sea ports to smaller inland ports.
Fender: A resilient device, usually movable, interposed between a ships hull and the harbour walls or other vessels to minimize impact and prevent direct contact so reducing the risk of damage.
FEU: Forty Foot Equivalent Unit. Measurement of container capacity of container ships. Equal to two TEU’s, Twenty Foot Equivalent Units.
Fiddley: Generally regarded as the space inside the funnel where all the uptakes come together.
Fillet: Rounded corner cut in plate or machined in a casting or as originally cast to alleviate stress concentrations found at a sharp corner.
Fineness: The ratio of the area of a waterplane to the area of the circumscribing rectangle. It varies from about 0.7 for a fine form vessel like a yacht to about 0.9 for a full form vessel such as a tanker.
Flagstaff: A flagpole at the stern of a ship, which should be used to carry the ensign of the country of registration. For UK registered vessels that would be a Red Ensign for Merchant Navy, White Ensign for the Royal Navy and a Blue Ensign for RFA or a Merchant Navy Vessel with a Captain who is a member of the Royal Navy Reserves. Also known as Recd White and Blue Dusters.
Flanking Rudders: Additional rudders fitted in front of the propellers.
Flap Rudder: A rudder with a separate tail flap that moves in an angle greater than the main rudder. This gives much increased lift and can generate thrust at 90 deg to the vessel.
Flare: Outward curvature of the side plating at the forward end above the waterline.
Flat: Minor internal, usually lower, deck. Usually without sheer or camber hence its title.
Flat Margin: A double bottom construction where the tank top extends horizontally to the ships side.
Flat of Keel: Width of the horizontal portion of the bottom shell, measured transversely. Also called the Flat of Bottom.
Flat Plate Keel: Middle or center line strake of plating in the bottom shell. It is increased in thickness for strength and as a corrosion allowance.
Flettner Rudder: Specially designed flap rudder using two narrow flaps at the trailing edge, one above the other.
Floating Dry Dock: An often misinterpreted definition. The dock is basically a large “U” shaped tank open at both ends. The tank is sunk by filling it with water. The vessel sails in, the tank is pumped out and it rises, picking up the ship in the process until it is completely out of the water carrying the ship.
Floor Ceiling: Wood covering placed over the tank tops for protection.
Floor Plan: Horizontal section showing the ship divided at the waterline or a deck line.
Floors: Vertical (yes vertical!) plating mounted in the double bottom tanks. They can be watertight, creating tanks. The floor structure is continuous from the centre girder to the side shell and supports the inner bottom shell. The arrangement of flooring will be determined by the framing system adopted, which could be either transverse or longitudinal.
Fluke: The palm of the anchor, i.e. the broad flat portion that penetrates the seabed and holds the anchor. It is worth noting that the ship is not held by the anchor but by the cable lying on the seabed. The anchor simply holds the end of the cable for accurate positioning.
Flume: A stabilization system using an athwartships tunnel connecting two wing tanks, the combination containing a set amount of water. The water travels along the tunnel as the vessel heels thus causing a dampening affect on the motion.
Flush Deck: An upper deck extending along a ships length without side to side structures.
Flying Bridge: An open control position located above the enclosed wheelhouse.
Fore Peak: A watertight compartment between the watertight collision bulkhead and the stem frame. Usually a ballast tank.
Foc’s’le: or forecastle or focsle etc. A raised deck at the bow below which the crew were traditionally housed.
Fork Beam: A half beam used to support a deck where an opening such as a hatch occurs.
Forward Perpendicular: A vertical line drawn through the point at which the stem frame cuts the Summer Loadline.
Forward Shoulder: The part of the hull where the bow area meets the parallel midships area.
Frame: Transverse structural member acting as a stiffener to the internal hull plating. Can also be longitudinal and can also be referred to as the ribs of the hull.
Free Surface Effect: An effect that can reduce stability, which occurs when a tank is not fully filled and is said to be slack. Free surface effect is not dependant on the depth of liquid and the degree of instability is the same whether the tank is nearly full or nearly empty. This effect is reduced by the inclusion of internal open bulkheads, which allow the passage of the liquid, but reduces its movement.
Freeboard: The vertical distance from the summer Load waterline to the top of the freeboard deck plating, measured amidships. The freeboard bears a direct relationship on the vessels seaworthiness in as such as the greater the freeboard the more stable the vessel will be in the event of damage or ingress of water.
Freeboard Deck: Uppermost complete deck exposed to the elements with a system of watertight enclosures to ensure the watertight integrity is maintained.
Freeing Port: Opening in the Bulwark to allow the fast removal of water accumulated on deck.
Freeing Scuttle: Flap fitted to some freeing ports to allow water to drain out but not enter.
Funnel: Structure containing all the exhaust uptakes, taking them to a height where the exhaust can clear the ship.
Funnel Guy: Stays or braces supporting the funnel, usually attached to a circumferential ring around the funnel. More necessary on riveted funnel structures.

**Bunkerbarge** · 18-04-2006

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.

rjwood_uk · 19-04-2006

have you ever seen a girding??

that must be quite scary!

**Bunkerbarge** · 19-04-2006

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.

**Bunkerbarge** · 22-04-2006

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.

**Bunkerbarge** · 23-04-2006

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.