[EMAIL PROTECTED] wrote: > "Ron Jones" <[EMAIL PROTECTED]> > wrote: > >Ken Hornstein wrote: > >> Nigel Bromley has a great web page on all this: > >> http://www.caffnib.co.uk/locks.htm > To see if you are as good as you think you are, have a try at: > http://terrax.org/sailing/locks/lockflightjs.aspx > Alright, I admit it, the first time I tried this game I caused > flooding. > >Sideponds do save water. Just the problem of getting the boaters to use > >them (and BW to maintain them).... I still remember clearing out the ones > >at Hanwell, I'll bet they are still not in use....
There are actually two different things that are both referred to as 'sideponds' in connection with staircase locks: (a) the economiser ponds sometimes also found by single locks. These are built adjacent to each chamber and connected to it via a paddle: this is opened first, and used to empty or fill the first part of the chamber, then when a level is made it is closed and the normal top and bottom paddles are used for the rest of the operation. Use of these sideponds is optional - the locks work perfectly normally without, but use more water. I know of only one staircase equipped with these (Bascote on the GU) and they have been out of use for a long time. (b) the type seen at Foxton and Watford, which take the place of the intermediate pounds between the locks. Instead of being built alongside each lock, they are built alongside each set of gates, with a paddle to fill them from the lock above, and another to empty them into the lock below, You can't help but use them, as there are no paddles to empty one lock directly into the next one. I have heard type (a) referred to as side *ponds* and (b) as side *pounds* but I don't know if this is in any way official. I reckon type (a) saves more water if the boats tend to arrive in bunches all heading in the same direction and type (b) if they generally arrive in equal numbers from both directions at the same time. I suppose you could build a staircase with *both* types... > You win. > BW claims that nowadays side ponds actually increase water > consumption, because most boaters don't know how to use them properly. > This, plus the cost of maintaining/restoring them, is why so many are > now not operable. There's another problem with sideponds: unlike normal paddles, sidepond paddles have to seal against a head of water in either direction. Apparently this can make them difficult to seal well, and if they aren't kept well maintained the leakage will negate the water saving, or even make them more wasteful than without sideponds. Hanbury Locks on the Droitwich got around this by fitting each paddle culvert with two paddles, one at each end, operated simultaneously by the same winding gear. I don't know if this method was used anywhere else. On the original question, although the amount of water used at Bingley locks might not be as much as the BW bod suggested, they must still have had a significant effect on water consumption for the whole canal. Given that the company went to considerable expense to build new reservoirs, perhaps it's surprising that they didn't try to do something about the 5-rise - for example rebuild it as a 3 and a 2 so it used no more than all the other staircases at that end of the canal. Martin L
