It is COLD in those tunnels!
It’s an odd thing but we do indeed have weather underground. We just don’t get it as fast as the rest of you. It’s severely delayed, if you will. :o)
Take the summer, for example, outside it can be roasting hot with people wandering around half-naked and down below we’re pootling along in a cool, pleasant environment. This is because the tunnels have a fairly stable temperature and it takes a number of days of extreme temperatures on the surface for any change to be noticed down below. So after a heatwave lasting a week we’ll certainly notice the difference, but otherwise it’s a nice temperature. And if it’s not then we have a reasonably good air cooling system in the cab (and can whizz along with our front doors open when we are on the surface).
Of course, the above statement is only concerned with the driver and not the passengers. Back in the actual train there are all manner of motors chuntering away and generating their own heat. We have air-vents on each car but that doesn’t do an awful lot of good. It’s often suggested that LUL should install aircon in the trains but aside from their being no room, that would only involve more heat being generated by the aircon system itself. Sadly the tunnels are not spacious enough to provide room to vent the heat.
For temperatures at the other end of the scale everybody is taken care of. Theoretically at least. Both cab and saloons have heaters and while they might be old and slow, once they do heat up things are generally toasty. Unless of course you happen to be in the part of the train that is nothing more than a tin can with gaping holes around the edges of the doors and windows. That can get a little chilly even with all four cab heaters on. It’s unfortunate that the stock isn’t draught-proofed but at least it’s snuggly-warm in the tunnels right? Right? Er, no, actually.
It’s the same story as before. One day of extreme temperatures will pass unnoticed underground. Give it a few weeks though and there’s a definite difference. It begins by feeling the cold gusting down the tunnel as it comes to surface. A week later and it’s getting cool five stops from the tunnelmouth. Another week and everyone is wrapping up warm down at the far end of the line. At the moment it’s desperately chilly and I’m just thankful that LUL provide plenty of warm clothing.