Cast-iron bridge substructure in the C&O Canal, below 31st Street in Georgetown. The vertical and diagonal members, and the horizontal members at the water line, appear to be made of cast iron, given the thick flanges, the chunks broken out of the flanges (indicating brittle material), the integral ends on the H-beams that appear to have been formed without welding, the tops of the round columns, and the varied curves in the right-most column. The concrete and I-beams directly above the columns probably were added more recently. Note the blue paint marks where the canal boat has bumped the columns.
This bridge is "structurally deficient," according to a listing available in August 2007. The bridge must present difficult choices for historical conservation. Luckily, the cast iron mostly is used in compression, where it is relatively strong.
________________________________________________
#11641 AutoLNN blend50 11640 PwUnsharp5011 IvQ85