Norfolk Southern Staunton River Bridge at Altavista

From Bridges and Structures
Jump to navigation Jump to search

Norfolk Southern Staunton River Bridge at Altavista

This tall deck truss bridge with plate girder approaches is located south of downtown Altavista. It is apart of the old Southern Railway main line (formerly the Richmond and Danville Railroad) that bypassed Richmond and extended from Washington to Danville and points beyond. The line itself is notable for its role in the Civil War, first as a supply line, and, more famously, as the route by which Jefferson Davis and the Confederate cabinet fled Richmond to the final capital, Danville. The bridge, however, likely dates from around the turn of the century. It is one of the many examples around the country of bridges that were built for the steam locomotive era, but remain capable of carrying the heavy loads of today. Adjacent to this bridge is the circa-1928 US 29 Business Bridge, a truss bridge that once carried the road equivalent to the Southern Railway.

The structure itself carries two tracks, another feature that underscores the fact that it was an important piece of the Southern Railway infrastructure. It consists of two Pratt deck truss main spans, plus a significant number of plate girder approach spans that cross an expansive flood plain. The two Pratt spans are comprised of seven panels, and feature heavy structural members. The majority of these are connected together with riveted gusset plates. However, the connections of the members to the top and bottom chords are made with pins, an earlier technology that was phased out in the turn of the century for the stronger and more redundant gusset plate connection. This likely indicates that the bridge was built in the 1890s or 1900s, when gusset plate technology was being introduced, but when some bridge designers may have been reluctant to commit fully. Riveted connections are more rigid, and thus the engineer may have included the pinned connections to allow the bridge to flex more easily. The truss spans are also skewed (evident by the unequal lengths of the front posts); the engineers appear to have done this in order to have the direction of the piers conform to that of the river.

The deck plate girder spans are supported by trussed steel bent towers that were assembled with rivets and gusset plates. The girder spans are relatively short in length, which may indicate a tepid acceptance of this method at the time. Above each tower the girder sections have been replaced with modern rolled steel, which stands out next to the rusty riveted sections.

I took many of the pictures of this bridge from the sidewalk of the US 29 Business Bridge. This is not a particularly pleasant platform, as it shakes when cars go past, as well as having many wood planks with dry rot. However, I can't imagine being able to take pictures of the railroad bridge without it being there.

Pictures

  • L: the south truss. C: the north truss. R: the underside of the north truss.

  • L: a shot of both trusses over the Staunton River. R: three panels on the north truss (note the combination of riveted and pinned connections).

  • Shots of the steel bent supports and deck plate girders.

  • Connections