Yesterday's C&O Canal trike trip took me to Catoctin Creek, at approximately mile 51.5*, where once the Catoctin Aqueduct carried the canal and the towpath across the creek. The aqueduct, which apparently had a faulty design, collapsed in 1973 (details here). The east arch of the aqueduct is all that remains in place. Unobscured parts of the arch are visible below and to the left of the bridge. The poster in the background in the next picture shows what the Catoctin Aqueduct looked like.
There is now a Bailey bridge spanning the creek. The metal frame of the bridge is held together by bolts visible in the above picture and clamp-like devices shown in the next picture.
There are now plans to restore the aqueduct (more info). I noticed several neat piles of large blocks along the towpath on the east side about 50 m from the creek. I suspect those are the recovered pieces of the aqueduct being readied for reconstruction.
Greenspeed Anura on the Bailey bridge. The bridge in the background is for trains.
*Locations along the C&O Canal are customarily expressed in miles from the starting point, mile 0, in Georgetown in Washington, D.C.