On 9 Jan 2009, at 10:08, Steve Heaven wrote: > On Fri, 2009-01-09 at 09:52 +0000, Andy Greener wrote: > > >> >> Probably, but we can still have a bit of fun debating the thermal >> transmission properties of a narrow lock (Wheaton Aston). Does more >> warm water get through a lock with or without a boat in it, and what >> about wide/broad locks? Does length matter? ;-) > > > > A lock certainly does have a effect on the freezing of the water in > the > vicinity. > Last weekend the S&W in the Kidderminster area was frozen hard up to a > depth of 15-25mm. > The water above Caldwall lock was frozen right up to the top gates. > The > lock was full and completely frozen. However below the lock was ice > free > for a distance of about 40-50 feet. I guess that was due to the > movement > of the water from the flow through the leaky bottom gates.
Hmm, kinetic energy -> heat - this gets better! So the area of clear water below the lock has a relationship to the potential energy 'stored' in the pound above and the leakiness of the gates :-) -- Andy Greener n.b. Whisper Pangbourne, UK http://www.nb-whisper.com "Just because you've always done it that way doesn't mean it's not incredibly stupid"
