Volume Nine - Pre-Victorian to the present day - even more aspects - Swing Bridge Connections : Penarth Dock, River Taff and Glamorganshire Canal . . .

Fig. 1 - A side elevation of the swing bridge over the River Taff. [520]

The bridge which gives two 60 ft. openings, is composed of a pair of wrought-iron plate girders, 144 ft. long over all, carried by a central pier, 20 ft. in diameter. The girders, which are placed at a distance apart, transversely, of 13 ft. 3 in. from centre to centre, are each 8 ft. deep at the centre and 3 ft. 6 in. at the ends. The web-plates vary in thickness from ¼ in. to ⅜ in., and the top and bottom flanges are each composed of two 7/16 in. plates, 1 ft. 3 in. wide, connected to the web by 3½ in. by 3½ in. by ⅜ in. angle irons. The main girders are connected by cross-girders riveted to the underside of their bottom flanges, these cross-girders being 10 in. deep, and being covered with 4 in. for planking, over which is placed oak planking 2 in. thick.

	The construction of the roller-frames, &c., by which the bridge is carried at the centre of its length, is shown by Figs. 2, 5, and 10.
Fig. 2 - cross sectional view of swing bridge.