On Fri, 04 Jun 2010 11:03:16 +0100, Neil Williams
wrote:

On Fri, 04 Jun 2010 09:56:27 +0100, Bruce
wrote:
Tube lines seem to have a headway of 2 minutes and a typical Tube
train has 7 or 8 cars.

Frequencies on the Tube are often lower off-peak and the coaches are
a bit shorter.


But they carry far more people, each of whom is emitting 150 watts of
heat sitting down, rather more when standing and even more when
walking.


I can't see it making much difference, though. The Merseyrail
loop/link tunnels are newer, larger, better-ventilated and cooled by
the water. Even with more trains I can't see them getting as hot.


Obviously the tunnels are larger, but they are not better ventilated.
London Underground's ventilation systems are very much more powerful.
They need to be, because of both the greater frequency of longer
trains and the very much greater number of passengers. I suspect the
daily throughput of passengers on, for example, the Central Line is an
order of magnitude greater than that on Liverpool's Loop Line.

I think the water is probably more of a bonus than a significant
factor, but it does help.