Strolling through the HAER collection of bridges got me by accident to a pair of bridges related only by their name: “Washington Crossing Bridge.” Today’s is over the Delaware River, between New Jersey and Pennsylvania, tomorrow’s will be the one at the other end of Pennsylvania, over the Allegheny River in Pittsburgh.
The name Washington Crossing makes some sense at the Delaware River. Having lost control of New York in the summer and fall of 1776 (during the battles of Long Island and New York), George Washington led the Continental Army across the Hudson River and south across New Jersey, more or less chased by a portion of the British army. In early December, Washington’s army crossed the Delaware to Pennsylvania and the British set up winter camps in New Jersey. On the night of December 25th, Washington took men back across the river to New Jersey for a surprise attack – inspiring a lot of paintings of him showing poor judgement by standing up in a small rowboat – and then after the successful battle and raid crossed back to Pennsylvania again. In short, there’s a stretch of the Delaware River north of Trenton that was the site of a lot of military action in 1776 and 1777.
A timber bridge with masonry piers was built connecting Hopewell Township, New Jersey with Upper Makefield Township, Pennsylvania in 1831, destroyed by a flood in 1841 and rebuilt then. The second bridge was destroyed by a flood in 1903 and the current steel superstructure constructed, reusing the old piers, in 1904. The mid-river piers have concrete caps, so they may have been raised slightly. The 1904 third bridge is still in service with a weight restriction on traffic, having been repaired after a flood in 1955 and rehabbed in the 1990s.
There are six through-truss spans, either identical or nearly identical in length, with the various references all saying that the longest span is 143 feet. What made this bridge interesting to me was that the trusses are double-diagonal Warrens without verticals (except at the portal frames), which is a fairly rare form. As usual, there are good pictures at the Bridgehunter.
The thin diagonals and top chord show that this was always a road bridge, as rail bridges of that era are much heavier. Without getting too far into aesthetic-dilettante mode, this is a good-looking lightweight bridge that avoids getting too far into spider-web territory. Hopefully it will survive any future floods on the river.
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