Kevin T of NB Tranquility got it. It is the breather for the ground paddles on a lock on the Huddersfield Narrow Canal. The pepperpot-shaped device seems to serve as a bollard or strapping post too.
This is at Lock 12W.
More on that important bed - The bed project is progressing very slowly as I’m trying to ensure there are no mistakes. Jarrah timber is expensive and wastage isn’t something we want...
4 hours ago