Until yesterday, that is. I arrived at the bottom of the staircase, and went to ensure it was setup for me to go up. To operate a staircase, the top chamber needs to be full, and the bottom empty. I was gobsmacked to find that the bottom chamber was empty, but so was the top one. It was not just half empty, but had a water level equal to the lower level of the lower chamber. This does beg the question "How on earth did anyone manage to get the lock into this state?"
Then today, I went for a stroll round the junction, crossing each of the arms of the junction. When I arrived at the staircase, a boat was trying to go down it. The operator had never done a staircase lock before, and was finding it very difficult to understand. Looking at the lock, I could understand his confusion. The top lock was full (in a normal fashion), but the bottom chamber was also half full. In this position it was impossible to operate it without first restoring it to a normal state. Again the same question - how had it been got into this state?
So fundamental questions of physics - how are people managing to coerce a mechanical system, designed to manage water over a gradient, and lift boats through a distance of (estimated) 4 metres, to end in a state that is extremely difficult to understand. (I can come up with a plausible scenario to explain the first of these examples, but not the second).
My brain hurts.