A Four-Track, Center-Bearing, Railroad Draw Span

The four-track draw span recently completed for the Bessemer and Lake Erie Railroad at Conneaut Harbor, Ohio, is of interest mainly on account of the special type of construction necessitated by the extremely limited height from base of rail to masonry. It is somewhat unusual to be required to support a draw span 235 ft. long and 67 ft. wide, with a turning load of nearly 1400 tons, in a depth of 5 ft. 8 in. Moreover, the frequent high-water stage made it necessary to limit the depth of the floor system to 3 ft. 3 in. from base of rail to underclearance. To conform to these conditions, in a bridge designed for Cooper's E-60 engine loading, necessitated short panels and floor-beams of single track length. A radical departure from standard types of construction was evidently necessary. The unusual width of the structure, together with the limited height available for the drum and the distributing girders, evidently excluded from consideration the rimbearing type of center.