Unless otherwise noted, all illustrations and text are copyright 1997, E W Wall.
The northernmost truss is a Pratt truss of the style typical for this bridge. In the photograph of the south portal you will notice that the rails are cut to points to fit the swallowtails in the rails of the bascule, and are fitted to a mechanism to lock the rails in place when the bridge is lowered. The photo below shows the swallowtails on Span 7. Note also that the guardrails on the northbound (downstream or eastward tracks, closer in the photos) are set back from the Rest Bearing, while those of the southbound tracks go all the way up to the Rest Bearing. Click on the thumbnails below to see larger images.
Here are details of the pier carrying the south end of
the span and the Rest Bearing. The red object in the right of the photo is a bracket on
the Acosta bridge.
To the left are details of the rivet patterns on the south portal of the span. Below are details of the north portal.