Adrian Stott wrote: > "Bru" <[email protected]> wrote: > >> Adrian wrote ... >> >>> Caen Hill has side pounds. >>> >>> Bratch has side pounds. >>> >>> Foxton has side *ponds*. Not the same thing at all. >> <clang> wrong! > > I'm afraid not. > >> Foxton has, technically, side *pounds* not side *ponds* (although they are >> usually referred to as ponds) > > A side *pond* is an unnavigable body of water into which (depending on > the type, some or a whole lockful of) water from a lock can be drained > and out of which water can be let into a lock. It is provided to > allow the lock to be worked using less water than would be required > without the side pond.. > > A side *pound* is a an extension of a (navigable) short pound to the > side, provided to increase the surface area of the pound and thus to > decrease its variation in water level during locking. Some of these > extensions are navigable (e.g. Caen Hill), others are not (e.g. > Bratch). As there is no pound between the locks at Foxton (except the > passing pound), the bodies of water next to the Foxton locks can't be > side pounds.
The Foxton and Watford ones are logically identical to the Bratch ones. They are all pools of water connected to - via some combination of gates and paddles - the full water in one lock and the empty water in the next. In each case there is no route from one lock to the next that doesn't involve going through the pound. Indeed, I've long theorised that the reason for Bratch is that Brindley hadn't invented the staircase with side po[u]nds, so put the extra gates in. All that aside, the terms are used pretty well interchangably, as my Google on Devizes shows. But if you did want to make the divide between those that are at the "interlock" water level and those that go up and down to save water, then Devizes, Bratch and Foxton are in one set, and Atherstone and Hazlehurst in the other. Anyway, those with long enough memories know that the proper term is "ponud".
