Engineering Wonders of the World
Volume I

182 ENGINEERING WONDERS OF THE WORLD. wilson’s steam navvy at work on the new dock, SOUTHAMPTON. A truck-load of material is removed at each stroke of the scoop. (Photo, S. Cribb.) LÜBECKER BUCKET LADDER EXCAVATOR AT WORK ON THE BOULOGNE (FRANCE) HARBOUR. (Photo, The Lübecker Machine and Manufacturing Company.) dock just mentioned the entrance was thrown open to the river while the walls were being built, and bucket dredgers began to work their way into the piled-up sand heaps. The sand they dredged was discharged into hopper barges, which carried it down- stream to the estuary and deposited it in the deeper part of Loch Long. When the 82 acres had been dredged to the depth of the river outside, the basins were ready for occupation. Often, however, the site of a dock is partially covered by the tide, and occasionally a portion of the area has to be actually reclaimed from water. Here the engineering presents difficul- ties which are not always disclosed by inary survey indicated it to be. The quay borings. But in normal circumstances the tide walls are built in trenches, the displaced sand may be shut off from such a site by using the being piled high in the spaces that will be water area when the undertaking is complete. Sometimes steam excavators are used; but, as a rule, the digging is done by manual labour, the soil being loaded on wagons and dumped by the works railway wherever convenient. At the entrance to a basin of this kind—on the river- side, that is—a coffer-dam or an enclosing bank has to be made to keep the water away from the workings while that part of the enterprise is in progress. But elsewhere, if the ground is good, the con- structive work is simple. On the completed quays ware- houses are built, and railway lines are laid, linking up the dock with the main systems. In the case of th© Glasgow