"Roland Perry" wrote in message
...
In message , at 12:54:36 on Mon, 5 Aug 2019,
NY remarked:

What is the typical number of lock-emptyings per hour that a canal can
handle?

Depends on the size of the paddle-gear. But one lock every five minutes is
about the fastest one would normally achieve.

However, you don't do it like that - the correct method is to open the
paddles both ends, which will at least double the flow compared to a lock
full ever five minutes.

Ah yes, I was forgetting about the paddles (I, too, would have called them
sluice gates, but I stand corrected) which would be needed anyway to fill
the pound before the upper gates could be opened.

So if you needed to transfer a lot of water in the shortest time, how long
could you leave the paddles of all the locks open without damaging the
sides/bottom of the canal by scouring? I wonder if that is being done in
parallel with pumping water directly out of the reservoir into non-canal
waterways?

450,000 litres every 5 minutes by the lock paddles is a hell of a lot more
water than 7000 litres every minute by the pumps. But that is making the big
assumption that it is OK to drain a lock's worth of water every five minutes
as a sustained rate over many hours, rather than just a burst rate with gaps
in between.