RIVER THAMES
Ciiap. VIII.
BRITAIN.
313
Brunswick Wharf in front of the East India Docks. In 1834 this quay was found to bein a state of decay, and being required for the accommodation of a large class of steamvessels, Messrs. Walker and Burgess were employed as engineers to put it into a properstate, and the new iron piling and wharfing were executed.
A trench 6 feet wide was opened in the direction of the intended line, and the guidepiles were then driven; the main piles, which are of iron, were placed at intervals of7 feet, and the intermediate bays were filled in with the iron plates. The piles are each intwo pieces, the upper one fitting into a socket-head formed on the lower, the union beingmade perfect by a strong screw bolt: each sheet pile is secured at the top by two bolts tothe uppermost wale of the woodwork immediately behind them ; they are of iron 1-J inchesin thickness, and the weight of each is 17 cwt.
These plates filling up the spaces over the sheet piling are bolted to the main piles, andto each other, and the joints stopped with iron cement, and where the mooring rings areintroduced, they are cast concave with a hole to allow a bolt to pass through, which issecured as well as the land ties from the main piles to the old wharf, which was notdisturbed.
The West India Docks are considerably larger than the London , and are situated about1J miles below them in the Isle of Dogs, on a peninsula formed by the winding of theThames . These docks were commenced on the 12th of July, 1800, and as early as the
IMPORT DOCK
BASIN
EXPORT DOCK
SOUTH DOCK OR CANAL
TIMBER DOCK
Fig. 317.
month of September, 1802, vessels entered the import dock. There are two docks, eachabout 890 yards in length, running parallel to each other; the largest, 500feet in breadth,and destined for vessels returning from the West Indies , contains about SO acres; theother, 400 feet broad, about 25 acres. The docks, basins, and locks, together form an areaof 68 acres, whilst the total superficies, including the quays and warehouses, is 140 acres.204 vessels can be admitted into the import, and 195 into the export dock, forming atotal of 120,000 tons.
At the upper end is the Limehouse basin, containing 2 acres, and at the lower theBlackwall basin, containing 6 acres.
The docks lie almost from west to east, and the principal entrance, that of the importdock, is from the west; at the upper and lower end is a basin with three locks; the firstcommunicates with the Thames , the water being retained by double gates ; the second andthird locks also have double gates, and communicate with the export and import docks.By these arrangements vessels can enter the basin whatever may be the state of the tide,and remain as long as may be required.
As the water in the docks is very little higher than that in the basin, there is no stressupon the lock gates, and remaining some time in the basin before it is passed into the docksthe sediment is entirely deposited.
Parallel with the northern quay of the import dock is a range of sheds, 8S0 yards in length,which communicate with the warehouses, six stories high. The sheds are supported by cast-