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.
Why??? - Sometimes I despair at the mentality of some folk. I'm not entirely sure what the leaving of paddles up on both top and bottom gates will achieve other tha...
36 minutes ago