Wallsend Dry Dock

[Whickham]

A view of the largest dry dock at Wallsend, some 715 feet.

Photo courtesy of the Evening Chronicle

[Terrysummerson]

obviously taken before they dug the sonar pit

[Terrysummerson]

article from the Shipbuilder.
THE NEW LARGE DRY-DOCK AT WALLSEND.
The Shipbuilder 1957

THE official opening ceremony of the new large dry-dock, at Wallsend, of Messrs. Swan, Hunter & Wigham Richardson, Ltd., was performed by Her Grace The Duchess of Northumberland on the 14th May, 1957. This dock represents not merely a numerical addition to existing installations, but an advance on previous docking capacity.
It will accommodate oil-tank ships of up to 42,000 tons deadweight and even some—depending on their ratios—of 45,000 tons deadweight, as well as passenger liners and
warships.
It was in order to maintain their position as prominent ship-repairers that Messrs. Swan, Hunter & Wigham Richardson, Ltd., decided, in 1953, to embark upon the construction of a dry dock substantially larger than any of their three existing docks. Messrs. T. F. Burns and Partners, of London, were appointed to act as consulting engineers for this important project, which entailed the construction of a dock 715ft. in length by 105ft. in width and with a depth of water of 29ft. 0in. over the sill at H.W.O.S.T. The contract for the construction of the dock was awarded to Sir Robert McAlpine & Sons (Newcastle-
on-Tyne), Ltd.

TECHNICAL DETAILS.
Consideration was given to various methods of forming the dock walls, but in view of the evidence that ground water, in considerable quantity, probably existed, combined with the presence of soft clays and silts, it was decided that the in situ concrete method of walling was advisable. The walls have two bilge altars, a top altar and one cantilever altar, faced with greenheart, to accommodate side shores. The walls are built in 55-ft. lengths with a 5-ft. contraction gap, thus making each unit 60ft. long. The dock floor is designed to act as an inverted arch under hydrostatic pressure and is 14ft. thick at the centre and 10ft. thick at the sides, where it is keyed into the walls by a bird's-mouth joint.
The pumping equipment has been manufactured by Messrs. Drysdale & Co., Ltd., of Yoker, Glasgow. The pump house and drainage sump are located about 120ft. from the entrance, on the northern side of the dock. Two main electrically-driven (48in./45in.) horizontal-spindle centrifugal de-watering pumps are installed. These units are each driven by a 580-B.H.P. slip-ring motor, and when they operate together they are capable of emptying the dock in 2.5 hours. The anti-siphonic system of discharge is employed. This involves the use of two 54-in. diameter reinforced-concrete culverts constructed in the form of a siphon.
A box-type gate, constructed by Sir William Arrol and Co., Ltd., of Glasgow, is used, and has an overall length of 111ft. 4in. and a depth of 35ft. It is of welded cellular construction. The meeting face is welded to the gate and consists of a 12in. by 3in. steel bloom, which bears on concrete quoin stones when the gate is closed. The gate is raised and lowered by an electrically-driven winch. Operation is by means of push-buttons from a pillar control situated alongside the entrance.
Crane tracks, of 25-ft. gauge, are arranged on both sides of the dock. Between the tracks, a 24-in. thick reinforced concrete slab is provided to carry a standard-gauge rail track, as well as road vehicles. On the north side of the dock there is a 10-ton electric, travelling, level-luffing portal-type crane, which has been constructed by Messrs. Stothert & Pitt, Ltd., of Bath. This unit is capable of lifting 10 tons at a radius of 115ft. On the north side of the dock, a 50-ton crane (by Sir William Arrol & Co., Ltd.) of similar type to the 10-ton unit, but not level-luffing, is installed. This unit is capable of lifting 50 tons at 90-ft. radius, with an auxiliary hoist of 10 tons at 135-ft. radius. It is capable of lifting to a height of 95ft. above cope level, and can, therefore, reach over a ship to the other side of the dock. Electric power is supplied to the cranes by means of a pick-up arm operating on three copper conductor T-bars, fixed in a trench constructed immediately above the cope level. It was appropriate that the first vessel to have had the privilege of using these new docking facilities should be the British Valour, built at Wallsend by Messrs. Swan, Hunter and Wigham Richardson, Ltd., for the B.P. Tanker Co., Ltd., of London. This vessel entered the dock on the 16th May, for her final docking before she proceeded on her trials.

[magoonigal]

Great stuff, Terry!

[tynebuoy]

March 1956.

[Whickham]

and I presume this is BRITISH VALOUR "doing the honours"

See: viewtopic.php?f=13&t=1250&p=33989#p33989