Glossary of terms connected with docks and riverside sites

Glossary of Technical Terms used in Connection with the Docks and Riverside Sites

Accumulator: an apparatus for collecting and storing water pressure or electricity.

Altar: a step or ledge in the wall of a dry dock, used to hold the wooden supports which steady the vessels when the dock is empty.

Apron: a platform or hard surface at the bottom of a dock entrance to intercept the fall of water and prevent the erosion of the bottom.

Bascule bridge: a type of drawbridge, hinged, with a counterweight, which raises to allow ships to pass beneath it.

Caisson: a pontoon or floating gate used to close a dry dock; also a watertight chamber or other structure used, often in combination with compressed air, to keep water or soft earth out of a site during construction work; also an apparatus for lifting a vessel out of the water for repairs or inspection.

Campshedding: a retaining wall of timber piles to protect or hold back the river bank.

Chevaux de frise: a line of spikes or nails fixed along the top of a wall or railing.

Coal-meter: one who measures or weighs coal.

Coal-whipper: one who raises coal out of a ship's hold by means of a pulley.

Counterfort: a strengthening pier or buttress in a retaining wall.

Derrick: a contrivance or machine for hoisting and moving heavy weights; a simple crane (apparently the surname of a celebrated seventeenth-century hangman at Tyburn).

Drawdock: an inlet in a river where boats can unload cargo or lie at low water.

Dolphin: a post, buoy or platform for mooring a vessel, sometimes situated at the entrance to a narrow harbour or dock as a guide to shipping.

Fairleads: see Snatch-heads

Garner: a store or granary.

Graving dock: a dry dock, originally a dock where ships' bottoms were cleaned and smeared with tar (a process known as graving, possibly derived from graves or greaves, the dregs of tallow).

Greenheart: a South American hardwood.

Gridiron: a wooden framework on to which a ship could be floated at flood tide, allowing for repairs and maintenance when the water receded.

Heel post: the corner post of a lock gate, to which the gate is fastened

Invert: an inverted arch, as at the bottom of a canal or sewer.

Jigger: a loose chain used as a light warehouse crane.

Loophole: one of the vertical series of doors in a warehouse, through which goods are delivered by crane.

Level-luffing crane: a crane which, during luffing (the raising or lowering of the jib), maintains the load at a constant height, moving it horizontally.

Luffing crane: a crane with the jib hinged at the foot to allow the angle of operation to be altered.

Mould loft: a room where the drawings were turned into full-size templates or 'moulds' for the shipwrights to work from.

Paddle: a sliding panel in a lock gate or sluice gate which regulates the flow or level of water.

Penstock: a sluice gate for controlling water flow, which opens by lifting upwards.

Pug mill: a machine for mixing and tempering clay.

Scoop wheel: a wheel driven by wind or steam for lifting water.

Scupper: an opening in the side or floor of a building to allow excess water to drain off.

Sheerlegs (also sheer legs or shearlegs): a device for lifting heavy loads, consisting of two poles lashed together at their upper ends, from which a pulley is suspended.

Snatch-heads or fairleads: fixtures used to alter the direction of a hauling rope or cable.

Toe: the part of the base of a dam or retaining wall on the free side, away from the retained material.

Trunnion: one of a pair of side projections on which an object (such as a cannon) is pivoted to move in a vertical plane.

Turning bridge: a bridge turning horizontally on a pivot; a swing-bridge.

Wales or whales: horizontal supports (usually of timber, sometimes of iron) used to bind together piles driven in a row.