The Viaduct Works' Handbook

57 railway bridge of double line or for a jetty 26 feet wide. The trans- verse view of its supports will be found and described at pages 50 and 51. The superstructure is composed of wrought-iron lattice girders, of 30 feet spans, each span containing four inner and two outer girders; the whole of the floor is covered with buckle-plates, of reths of an inch thick, rivetted to the girders and to cross stiffening strips at joints; handrail, bolted on each side, consists of cast standards and li-inch wrought-iron gas pipe. The weight of iron in this super- structure is about 74 cwt. per foot run; and taking the price at £16 per ton, f. o. b., it gives the price £6 per foot run, and adding the cost of piers, say one to each span, at the price named at page 52, namely, for 47 feet pier £2 15s. per foot of height, or £129 5s. each, which, divided by 30, gives about £4 5s. per foot run of jetty, making total cost per foot run £10. Amongst other piers, jetties, &c., manufactured at the Viaduct Works, and erected by the proprietors, may be mentioned a pier at Wellington, New Zealand, for landing passengers and merchan- dize. The landing-stage is 300 feet long, 50 feet wide, and is connected to the shore by a somewhat narrower jetty, 160 feet long, 35 feet wide, sufficiently strong to carry a load equal to 1 cwt. per square foot all over its surface. The deepest water is about 25 feet at low water and 29 feet at high water; the level of floor is about 6 feet above high-water mark; the piles are sunk about 20 feet into the ground, and are about 55 feet total length. The land- ing stage is composed of 19 main girders, each 50 feet long, placed transversely about 16 feet 6 inches apart, each girder being sup- ported by one cylinder pile, 4 feet diameter, and three screw piles, of 12 inches diameter, placed equidistant under it, the cylinders being on the sea-face of the stage; the last girder at each end of the stage is supported by four cylinders. Thus the whole of the supports on the sea-face and ends are composed of 4 feet cylinders, the inner supports being 12 inches diameter screw piles. Between the 50-feet main girders are placed lighter girders, in a direction at right angles to them, or longitudinally with the stage, the top flanges of which are even with those of the main girders, to which they are rivetted directly over their points of support. The piles are all braced to- gether horizontally by wrought-iron girders, securely attached to them at a distance of 8 feet from the top, and between these and