Canalside Crane (III)

The third of a number of canalside cranes I have encountered. At first they were a puzzle - of considerable age and yet maintained.

Then I came across another and their purpose but only this third seems to be complete, still having an entire "door" ready to be lifted over and then lowered into the canal to seal off one end of a section.

This one is close to one end of the Swing Aquaduct Bridge and must be of particular significance.

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