A non-dimensional number indicating the relation between a vessel’s length and its speed, expressed as Fn = V / √gL ; where V = speed, g = acceleration due to gravity, L = length of the vessel

Keyed-taper connections, splines, bolted connections and clamped flanges give rise to fretting failure. The basis is two surfaces which are able to move relatively to each other, even by a small amount, leading to contact scars.

The contact between two surfaces under pressure and subject to a slight relative motion.

A unit used for conversion of sea, well or effluent water into freshwater by vacuum distillation based on evaporation and condensation.

CONTENTIN has been built at the Aker, Helsinki shipyard for UK/France service. The large superstructure at the fore end of the upper deck contains 121 two-berth cabins with en-suite facilities for drivers, together with dining and leisure services.

A halogenated hydrocarbon usually given a number which is related to its chemical formula. It is used as a refrigerant.

A sum of money paid for the hire of a ship or for carrying goods by sea.

A temperature at which a liquid solidifies under controlled conditions.

An opening in the lower portion of a bulwark which allows water shipped on deck to run freely overboard.

A set of drawings showing external openings (cargo hatchways, small hatches, ventilators, air pipes, side scuttles and windows, weathertight doors, scuppers and sanitary discharges, sea inlets and outlets) and details of their closing appliances.

see Load line mark.

Normally, the uppermost complete deck exposed to weather and sea, which has permanent means of closing all openings in the weather part thereof, and below which all openings in the sides of the ship are fitted...

Freeboard is the distance measured from the waterline to the upper edge of the deck plating at side of the freeboard deck amidships.

The unrestricted fall of liquid into a tank.

A lifeboat constructed for free-fall launching. The certificate of approval for a free-fall lifeboat shall state free-fall certification height, required launching ramp length, and launching ramp angle for the free-fall certification height.

A method of launching a survival craft whereby the craft with its complement of persons and equipment on board is released and allowed to fall into the sea without any restraining apparatus, (SOLAS, Chapter III).

The greatest launching height for which the lifeboat is to be approved, measured from the still water surface to the lowest point on the lifeboat when the lifeboat is in the launch configuration.

The rate of change of velocity experienced by the occupants during launching of a free-fall lifeboat.

When a tank is partially filled, the liquid’s centre of gravity position will change as the ship is inclined. Liquid in partially filled tank always decreases the initial metacentric height GM, righting lever GZ, and angle of vanishing stability.

Arrangements of stiffeners used to support hull plating. Two different types of framing are in general use or may be combined. They are longitudinal, transverse and combined framing.