[davemac]

I am starting to question the sanity of some of the contributers to this thread, the idea that shopping trolleys pose a threat to the canal is misguided. It is known that shopping trolleys prefer shallow water due to their lack of buoyancy, plus they like to disguise themselves, see attachments for proof, this would not be possible submerged.
The fact that trolleys are found in the canal is a misjudgment on the trolly's part and once placed is irreversible.

The extinguisher has not moved position, just rotated on its axis, the reason for this is unknown at this time.