At the middle set, I felt like we must be already at the top, as I had worked quite a few already, we had bobbed back and forth helping at each of the pairs of locks. Added information I hadn't seen before was at the top lock, telling you who was on duty, so assuming they update it, thanks to Jane! I saw the other chap passing briefly, but didn't work any locks with him, but I am sure he was busy, as we had been, since they are allegedly the busiest in the country.