"Mike Stevens" <[EMAIL PROTECTED]> wrote: >From: "Neil Arlidge" <[EMAIL PROTECTED]> >> The majority of Rochdale locks do have by-weirs. It would be interesting >> to find out whether the canal was initially built with, or with out them. >> <que detective Mike!> > >I'm sure I read somewhere, possibly here a few years ago, that the Rochdale >was built, like the K&A, without by-washes but they were added during the >restoration.
IIRC, the K&A did not have bywashes. Instead, if the upper pound were too full, water would flow over the top of the top gates (until the lock were full) and then over the bottom gates. However, during restoration, this design feature was misunderstood, and quite a few of the new bottom gates were built too tall. The result was that several pounds became liable to flooding. To deal with this, instead of altering the new gates (which was claimed to be much too difficult, although it never appeared so to me) BW first started insisting that all locks be left empty with the bottom gates open (that's a *great* way to save water on a notoriously water-short canal, eh?), then started building bywashes all along the canal. Too bad. Adrian Adrian Stott 07956-299966
