Looking through some old holiday photo's to while away a cold Sunday afternoon, I came across these taken at Buckby Bottom Lock (next to Whilton Marine).
They were taken in August 2013.
In the first picture, we entered the lock to go down with another boat. The lock had almost emptied, when water began flooding in over the top gates. Both boats had to move forwards to avoid being flooded (thank the diety of your choice we were not in a full length boat),
The lock began to refill, even though both bottom paddles were open and refilled to about 3/4 full. Then the water stopped coming over the top gates, and the lock emptied normally and we opened the gates and left.
The second photo was taken the next day, and shows a hire boat entering the same lock. Again, as he entered the lock it began to fill rapidly even though the top gates were open, so much so that the water overflowed the bottom gates!
After a few minutes the excess water ceased to flow and the lock could be operated normally.
So can anyone explain what was happening?
I don't think someone mis-operating a lock above could cause such a flow for so long, and the only other possibility I can think of would be a fault with the back-pumping system.
I have been through Buckby locks many times and never seen anything like this before.