A friend of mine sent me this link to an article that discusses how the London Underground frequently reaches unbearably warm temperatures in the summer.
And a problem it is! I went into London this past weekend and rode on the Circle Line. It was a little like descending into the maw of Hell! It did not help that the line was absolutely crammed to capacity (because of scheduled engineering works to other lines) and that it was running behind schedule (because of power outages caused by the heat). In fact, that merely enhanced the image of being in Hell!
Apparently, they have been having contests for years to suggest solutions to the problem. The proposed solution that this article discusses, is to used the ground water which (with rising water levels over recent years) would flood the stations should they not pump the water out. The plan is to use the water in evaporative heat exchangers before pumping it of to wherever they are sending it. The plan was that if the trial works this year, they’ll start retrofitting the tube stations with these machines to cool them in this manner. They should be done by 2009.
I have a much better solution which would be cheaper, does not involve any new machinery, and can be done a year before. Furthermore, it is fairly easy to explain being that it works on a straight-forward law of physics. The law is that gases cool as they expand. The solution is to introduce a vacuum into the tubes to make the air in them suddenly expand. This will cool the air. Now, I can have this system in place for in 2008. The vacuum sources I intend to use (Bush’s head and Cheney’s soul) are otherwise engaged until then.
I hope that wherever you are today you are managing to keep cool!
Don Bergquist - 26 July 2006 - Thames Ditton, Surrey, UK