C
Cable Stopper: Device used to secure the anchor cable and take the load off the windlass when the vessel is riding at anchor.
Camber: Curvature of the deck in a transverse direction. Camber is measured between the deck height at the centre and the deck height at the side. Also called Round of beam.
Cant Frames: Frame not square to the centre line such as in a cruiser stern. Not required with a Transom Stern.
Capstan: Barrel device or rolling concave drum, on a vertical axis, used for heaving in mooring lines or anchor cables.
Carvel Built: Type of ships plating made flush by Vee Butt welding or Butt Strap riveting.
Caulking: 1) making jopints watertight by filling seams of deck planks with Oakum. 2) Method of closing butts and seams of riveted steel plating.
Ceiling: Timber placed across the floor of a cargo hold to protect it from damage.
Cellular: Structural arrangement where a compartment is divided into small spaces such as a double bottom.
Centre Girder: Continuous longitudinal girder in the double bottom that runs fore and aft on the centre line.
Centre of Buoyancy: The centroid of the underwater volume and point through which the total buoyancy force it assumed to act. For a ship to float on an even keel the centre of buoyancy must be under the centre of gravity. The position of the centre of buoyancy is dictated by the loading of the vessel.
Centre of Gravity: The point through which the total mass of the vessel is assumed to act. The position of the centre of gravity of a ship depends on the distribution of internal masses. The stability of the vessel is directly related to the difference vertically between the centre of buoyancy and the centre of gravity. The greater this distance the greater the stability.
Chain Locker: A compartment that holds the anchor chain and also contains the ‘Bitter End’ connection.
Chock: 1) Smooth surfaced fitting at the weather deck side through which mooring ropes are led. 2) Wedge for securing a hatch cover or adjusting the alignment of a piece of machinery such as an engine, pump or gearbox.
Clinker Built: Each strake or plank of the hull construction overlaps the strake below. Generally used only in small boat building.
Clipper Bow: A bow where the stem post is concave in form as it rises from the waterline forming a bowed shape, like the Kreigsmarine “Atlantic Bow”.
Coaming: vertical plating bounding a hatchway. Heights of coamings depend on hatch position, some being more exposed than others. Coaming may be omitted altogether if directly secured steel covers are fitted. The height of the coaming is dictated by the Merchant Shipping (Load Line) Rules of 1968.
Cofferdam: A void or empty space between two bulkheads or floors preventing contamination of the two spaces contents.
Collision Bulkhead: Foremost transverse watertight bulkhead extending to the freeboard deck. Designed to limit entry of water in the event of a bow collision.
Companionway: 1) Set of steps leading between decks. 2) Ladder used for embarking and disembarking the vessel.
Compartment: Subdivision of the hull by transverse watertight bulkheads, creating compartments that allow the vessel to remain afloat and upright after flooding.
Conning Position: Part of the bridge with a commanding view from which the vessel may be conned (steered) when underway.
Controllable Pitch Propeller: Propeller made up of a boss with separate blades mounted onto it. An internal mechanism enables the blades to move simultaneously through an arc to change the pitch angle and therefore the pitch. Astern thrust can be generated without the need to reverse the rotation of the shaft. CPP units are generally not as efficient as fixed pitch propellers so tend to be used where manoeuvrability is more of a consideration than efficiency such as in ferries.
Crows Nest: Look out position on the upper foremast. Rarely used nowadays.
Crutches: Posts or saddles on the deck forming a crutch that the ends of derricks can rest and be secured when not in use.
Cycloidal Propeller: Combined steering and propulsion device comprising of a number of vertical blades arranged to rotate and revolve to give thrust in any desired direction. The most common form of these is the Voith Schneider unit. |