Engineering Wonders of the World
Volume I

TRANSPORTER BRIDGES. 289 bridge, which is simply a girder, fixed or sus- pended at a height sufficient to clear the tops of the ships’ masts, spanning the entire width of the river or estuary, and resting upon supports on either side. To the under side of the girders are attached rails, along which runs a trolley, supporting by vertical cables a car, with its deck at the level of the approaches. The trolley is actu- ated by certain gearing to take the car back- wards and forwards as desired. This the main principle of the transporter bridge, and the different methods of utilizing it have given rise to numerous designs of structure adapted to the various conditions of site and traffic and to the ideas of different engineers. Before describing the various types more particularly, it may be of interest to refer to an illustration (Fig. 2) which is the copy of a very old print in the possession of the Charlotten- The Transporter Bridge. A Primi = ti ve Transporter. burg Museum at Berlin of the FaustWranczi Bridge—a trans- porter bridge of a primitive kind, as the people in the car have to “ work their passage,” instead of being taken across by steam or electric power. The first transporter bridge designed on practical lines was made by Mr. Charles Smith of Hartlepool, who, in 1873, planned a bridge to cross the river Tees at Middlesborough. From financial or other reasons the scheme fell through, and the bridge was never built. (Fig. 3.) Since the design of Mr. Smith for the trans- porter bridge at Middlesborough, no attempt was made to The Portugaleti Bridge. adopt this system until many years later, when Signor A. de Palacio, an architect of Bilbao, in conjunction with Monsieur F. Arnodin, patented the system, and in the year 1893 designed and erected a bridge at Portugaleti, near Bilbao. (See Fig. 4.) Although the prin- (1,408) same as the pro- construc- ciple of carrying the traffic is the in Mr. Smith’s original design for jected Middlesborough bridge, the tion is entirely different, the supporting columns being fixed, and not hinged, at the bottom. Also, in place of the cantilever girders, the bridge has the form of a suspension bridge with stiffening girders. The distance apart of the columns is 528 feet, centre to centre ; and the clear height above high-water level is about 148 feet. An auxiliary cable is fixed to the end of the stiffening girders and se- cured to the anchorage, to control longitudinal movements of the girder. As the towers swayed to a considerable extent during heavy gales, steel wire guys were attached to them, fore and aft, as shown in the illustration (Fig. 4). This extra support has, however, not proved to be necessary in any of the more recent structures. A transporter bridge of similar type to the one at Portugaleti was constructed at Bizerta, in Tunis, by Monsieur F. Arnodin, having a span of 360 feet, and a clear height above the water-level of 149 feet. The car was about 30 feet long by 25 feet wide, and was actuated by rope gear driven by a winding engine. Owing to the extension of the harbour works at Bizerta, it has been found necessary to take down this bridge ; but there is a probability of it being erected elsewhere, and possibly when the harbour works are completed a larger bridge will be constructed near the site of the old one. In the year 1897 a transporter bridge was built at Rouen, the type being very similar to those previously described and designed by Monsieur F. Arnodin (Fig. 5). The bridge crosses the river Seine at a point about half a mile below the Pont Boieldieu, and has a span of about 472 feet. The car is actuated by rope gearing, but as electric current was available in the town, the machinery is driven by electric motors fixed on the top of the 19 Rouen Bridge.