Not sure if this really counts as urbex, but I think this is a fascinating bit of 1860s technology.
This contraption is the Locomotive Bridge (also known as a Turnpike Bridge or Lift Bridge) at Aspley in Huddersfield (round the back of Sainsbury's) which lifts a section of the road, cobbles and all, into the air so boats can pass underneath on the Huddersfield Broad Canal.
Until a few years ago this whole thing was operated using a manual windlass
But in recent years an electric motor was added, operated from this panel, having inserted a British Waterways key
This sign on part of the road gate interlock mechanism appears to pre-date the electrical installation