The Deptford Creek lifting bridge was constructed to allow the railway track to be raised so vessels with high masts could sail up the creek. This is the third incarnation, built in 1963, and is no longer in use, but is a listed structure.
https://frame-company.co.uk offer a good selection of frames and pre-cut mounts.
Limited edition 3 of 10 available
7.5 x 10cm / £30.00