Michael Askin <[email protected]> wrote: >There is also a working sidepound on the Hanwell Flight
There are important differences between a *sidepond* and a "side pound". The former is a water-saving device. It is a pond (well, yeah) at a lock, at an elevation between that of the pounds above and below the lock. Water can be let into it from the lock when the lock is being emptied, and let out of it into the lock when the lock is being filled. Several extant (but often not currently usable) examples have been mentioned in this thread. The latter is a feature for reducing the variation in the water level in a pound, especially that caused by locking. It does this by increasing the surface area of the water in the pound, and is normally an extension of a (usually very short) pound, which obviously always has to be at the same level as that of the pound, out to the side of the pound. Some are theoretically navigable, such as at Caen Hill (where they have been suggested as a location for moorings); others are definitely not, as at Bratch. I've left out complications such as the type of side pond found at staircases (e.g. Watford) and multiple side ponds at the same lock. The Hanwell example is a triple, i.e. three side ponds at one lock, although some of those on the Hanwell flight are doubles. Adrian . Adrian Stott 07956-299966
