Pictures 3 Bridgeport Swing Span Railroad Bridge, Bridgeport Alabama
1980 A 15-degree sideview of the swing span bridge in the open position, with the 364' - 0-1/2' swing span balanced on the center/pivot pier where the two (2) center supports deliver their loads onto a system of distributing girders, circular drum and rim bearing support wheels. The pier is circular and of stone masonry construction.
1980 Showing partial side view of swing span in closed position. The two (2) arms act as simple spans, a small amount of negative bending is accommodated by the continous top and bottom truss chords due to a continuous condition. Note the inclined end post of each of the simple spans, the operator's house, center/pivot pier and the pivotal pole-line pole placed atop of bridge.
1980 Detail of middle panel at pivot pier and above the two (2) center supports. The middle panel chords (not shown) were made strong enough to provide for the full bending moment with the span open and arms swinging. The middle posts support the operator's house. When closed, the bridge acts as two (2) separate simple spans, except a small amount of negative bending is accommodated due to a continuous condition.
1980 A 30-degree 'barrel shot' taken at track level showing operator's house in center of swing span and the track with timber ties. The ties are transverse (90-degree) to the track with each end resting on the bottom chord of the steel swing span truss, thus providing their support with live loads being transferred to the swing span truss bridge.
1980 Close-up view of portion of swing-span truss showing members and their pin connections at joints. The vertical member (hanger) shown is a portion of a small secondary truss added in each subdivided panel to help support the bottom chord. The track timber ties span the distance (16'-0') center to center of trusses, rest on the bottom chord and support the track. Note: Several of the members shown are eyebars.
1980 A 'barrel shot' looking down the track and through the 114'- 8-1/2' south thru truss approach span, showing pole line supported across top of steal superstructure. The 364' - 0-1/4' swing span over river has been used by various Railroads for a period of 90 years.