Glossary of terms connected with docks and riverside sites

Pages 725-726

Survey of London: Volumes 43 and 44, Poplar, Blackwall and Isle of Dogs. Originally published by London County Council, London, 1994.

This free content was digitised by double rekeying and sponsored by English Heritage. All rights reserved.


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.