"hungerdunger" wrote in message
...
| "Paul Herber" wrote in message
| ell.net...
|
| 100W+ per person, a couple of MW per train. It all ends up as heat.
|
| Yes, but from my (now possibly incorrect) memory of living in London many
| years ago, I seem to remember the Tube was OK in cool weather, but very
hot
| in hot weather. My point was: shouldn't the temperature be relatively
| stable all year round?
|
| --
| Hungerdunger

No! The movement of the trains continually drags in air from outside. Stand
on any platform, and you can feel the movement of air as the trains approach
and recede. And more to the point, when you are on the escalators, you can
continually feel the air flow, up or down depending which direction the
nearest train is running.. Coupled with Paul's comments above, then you can
see that there is a lot of heat being generated down there, and continual
hot air being dragged into the whole system during the summer.

The constant temperatures only apply when there is little or no movement of
air in the underground spaces, such as caves and mines.

jim, Northampton