Engineering Wonders of the World
Volume I

DOCKS. 175 there are, on waterways such as the Clyde and the Scheldt, not only river quays and docks, but jetties as well. The explanation is that, in order to keep down the capital cost of a port scheme, as increasing quayage without unduly enlarging the area of a port or the cost of working ships in it is by cutting up the site into docks. The ideal dock design is that in which the most quayage is shown in the smallest possible THE DREADNOUGHT GOING INTO DRY much as possible must be made of the site. Further, the port must be compactly arranged, or it will be a dear one for ship- Arrangement . « „ of a Port Pmg- Suppose, for instance, the tidal variation on the Thames in the port of London were as small as the tidal variation on the Scheldt at Ant- werp, and assume for a moment that all the available quayage from the Tower Bridge to Tilbury were ranged along the sides of the Thames, the eastern boundary of maritime London would be somewhere out in the North Sea. A port built on these lines could not be worked at a profit. Even jetties such as those at New York and Glasgow would not bring it into working compass. Jetties and river quays are excellent; but the most effective way of DOCK. (Photo, 8. Cribb.) area. This is achievable in a variety of ways. Two methods are illustrated by the Victoria and Albert Docks, London. The Albert is long and narrow, with just sufficient room for ves- sels to pass between the rows of vessels tied up at the quays; whereas the Victoria is com- paratively wide, with tongues jutting out into its water area. These are jetties, of course, but they are not quite the same as 1 Jetties river jetties. A river jetty is formed by cutting into the bank, whereas a dock jetty is built out into the water from the dock side. They achieve the same purpose, however, by accommodating at the very least two vessels where formerly one could barely be berthed. Better examples of the dock with tongues or jetties are the Tilbury, the Canada,