LARGE LONDON DOCKS

Taranaki Daily News, 1 June 1927, Page 9

LARGE LONDON DOCKS

NEW CONSTRUCTION WORK. So that the largest liners in the world may be able to dock just on the outskirts of London, engineers are carrying out a stupendous undertaking at Tilbury Docks, on the River Thames. They are driving 45ft. into the ground 119 concrete boxes, called monoliths, each larger in section a boxing ring, to form the side foundations of the enormous new entrance lock —the biggest in the Thames —which will permit liners of the size of the Berengaria, 52,226 tons, or the Olympic, 46,439 tons, to pass into the docks. Another 71 boxes of the same size are being sunk round the new dry dock, also the biggest in th. Thames. These concrete boxes are from 20ft. to 30ft. square and weigh about 1000 tons each. They are built up on the surface of the ground and slowly sink in by their own weight, to which is added the weight of 4y a -ton blocks of cast iron. Sometimes as much as 150 tons of cast iron are placed on the top of one monolith to force it down. Inside each monolith are four large wells and the clay forced up within these wells is scooped out by mechanical grabs lowered by a crane. The boxes sink into the ground at the rate of about l%ft. a day, although some sink as much as 3ft. in a day. The blocks of concrete for the sides and bottom of the dock and entrance lock are moulded at the docks. It is estimated that more than 550,000 tons of concrete will be nsed. The dry dock and entrance lock are, in effect, giant tanks of concrete.