Historic Structures

Pictures 2 Bridgeport Swing Span Railroad Bridge, Bridgeport Alabama

Bridgeport Swing Span Railroad Bridge, Bridgeport Alabama 1980 Showing partial side view of swing bridge in open position. The operator's house is in the center of the truss bridge, directly over the center/pivot stone masonry pier. Note the two (2) center supports with the truss loads being delivered to the drum by a system of distributing girders. The swing bridge revolved on a cylindrical drum supported by rollers running on a circular track on the center/pivot pier.
1980 Showing partial side view of swing bridge in open position. The operator's house is in the center of the truss bridge, directly over the center/pivot stone masonry pier. Note the two (2) center supports with the truss loads being delivered to the drum by a system of distributing girders. The swing bridge revolved on a cylindrical drum supported by rollers running on a circular track on the center/pivot pier.

Bridgeport Swing Span Railroad Bridge, Bridgeport Alabama 1980 Close-up view of a pin-connected joint where eye-bar and built-up members are connected with a single pin. This joint is at the apex of a small secondary truss added in each subdivided panel to help support the bottom chord. The vertical member shown is referred to as a hanger (or floorbeam hanger) and carries direct tension loads only.
1980 Close-up view of a pin-connected joint where eye-bar and built-up members are connected with a single pin. This joint is at the apex of a small secondary truss added in each subdivided panel to help support the bottom chord. The vertical member shown is referred to as a hanger (or floorbeam hanger) and carries direct tension loads only.

Bridgeport Swing Span Railroad Bridge, Bridgeport Alabama 1980 45-Degree view of one (1) arm of the swing span bridge in the open position. The view shows the continuous bottom chord of the truss. The vertical post and diagonal web members that frame into this bottom chord are connected with single steel pins at each panel point (or joint). The timber track ties, supporting the track, span from truss to truss bottom chords (16' -0') and are supported thereby.
1980 45-Degree view of one (1) arm of the swing span bridge in the open position. The view shows the continuous bottom chord of the truss. The vertical post and diagonal web members that frame into this bottom chord are connected with single steel pins at each panel point (or joint). The timber track ties, supporting the track, span from truss to truss bottom chords (16' -0') and are supported thereby.

Bridgeport Swing Span Railroad Bridge, Bridgeport Alabama 1980 Detailed view of one (1) arm of the swing bridge cantilevering out from the center/pivot pier on which the entire span is balanced at its center when in the open position. Both arms of the span have equal length. Note that the members are pin-connected at their connections (joints).
1980 Detailed view of one (1) arm of the swing bridge cantilevering out from the center/pivot pier on which the entire span is balanced at its center when in the open position. Both arms of the span have equal length. Note that the members are pin-connected at their connections (joints).

Bridgeport Swing Span Railroad Bridge, Bridgeport Alabama 1980 Close-up view showing portion of continuous bottom chord of truss with other web members and posts of the truss connected thereto at a joint by the use of a large steel pin. Note: The timber ties supporting the track (not shown but above) span transversely from truss to truss which are on 16' -0 centers.
1980 Close-up view showing portion of continuous bottom chord of truss with other web members and posts of the truss connected thereto at a joint by the use of a large steel pin. Note: The timber ties supporting the track (not shown but above) span transversely from truss to truss which are on 16' -0 centers.

Bridgeport Swing Span Railroad Bridge, Bridgeport Alabama 1980 Detailed view of one (1) end of the swing span, supported on a rest pier, with the span in the closed position and in the train operational mode. Note the end truss bearing where a steel wedge is in the driven position to complete the end bearing arrangement. The wedges are power-driven through the machinery crank arms shown, thus forcing the ends of the swing span truss upward. Note: The top of the old stone pies has been encased with a concrete collar to hold stone masonry together and strengthen truss bearing points.
1980 Detailed view of one (1) end of the swing span, supported on a rest pier, with the span in the closed position and in the train operational mode. Note the end truss bearing where a steel wedge is in the driven position to complete the end bearing arrangement. The wedges are power-driven through the machinery crank arms shown, thus forcing the ends of the swing span truss upward. Note: The top of the old stone pies has been encased with a concrete collar to hold stone masonry together and strengthen truss bearing points.