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Comment by mrtksn | Hacker News Reader

I wonder if this can be a solution to the heating problems on the older lines. I haven't done the math but a few weeks of closure or reduced service can be an opportunity for some heat exchange.

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It sounds like it took many decades for the surrounding soil to heat up, so without 100xing the rate of cooling from the soil relative to the existing rate of heating I'm skeptical, given that the heating resulted from a temperature differential of likely a few dozen degrees, you would need a substantially cooler environment to cool the soil. Maybe with a massive investment you could do it by cooling the tunnels to substantially sub zero temperatures.

More info for those like me who were unaware

https://en.wikipedia.org/wiki/London_Underground_cooling

Given that the trains are reported to be the largest sources of heat, the best solution in the long term will be new, more efficient trains.

New drivetrain technology is already far more efficient, producing less waste heat, than the decades-old stuff still being use on most London Underground lines.

In new trains, more powerful regenerative braking rather than friction braking will dramatically reduce heat produced from braking, for example. (It will mean less dirty air on the Underground, too!)

Thanks that was an interesting read. If the heat sink begins to dissipate are any structural risks to the network?

I can't find an online source to document this - but on a recent tour of Chislehurst Caves in SE London - the tour guide mentioned that during the second world war, when it was used as a bomb shelter for some 15,000 local residents, the heat built up inside to over 30°C very quickly. When the war ended he said, it took about 10 years for the temperature to return to it's now rather chilly 10°C.

Please don't fuel this bad reasoning - decreasing the number of trains or lowering their speed is a dangerous measure that will increase transmission!

It's the same brand of broken-mindedness that brought us the "only sick people should wear masks" and other wrong-think measures that increase transmission and make everything worse!

>the same brand of broken-mindedness that brought us the "only sick people should wear masks"

So apparently qualified health professionals having to deal with masks shortage are "broken-minded", but a bunch of armchair MD Internet commenters are correct.

If it was at the same capacity sure, but its been a ghost town (compared to normal) the last few days, so I doubt it will have a huge effect in that sense. It will also discourage people from taking the tube unless they have to (tbf they probably already were at the is point).

Well, nnq. Turns out you may have been right and owed an apology by those who downvoted you:

https://www.theguardian.com/uk-news/2020/mar/23/criticism-ov...

They don't have the staff due to people being off. Many of the other odd-seeming emergency measures taken or planned for in the UK have the same root cause. Even the school closures are more about staffing than reducing the spread of the virus; apparently that's a useful measure in flu pandemics because kids lack the immunity that adults do, but since no-one is immune to this as far as we know it's kind of weak here.

You make claims in italics, but you don't justify any of them.

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