I wonder though, if you were to take a reading right now of the temperature, what would it be? How well is the heat retained, with no trains moving about, there is static air, but no trains generating heat.
I used to get a (62TS) train that started out of Loughton sidings at about 8.35 am -- unbearably hot summer, as unpainted and east facing . But after that I gather they stabled with doors open both sides?
On the rare occasions when I've brought 1992s into service early in the morning the interior temperature is the pretty much same as the outside temperature so leaving the doors open while they're stabled wouldn't make much difference.
Not an earlies man then Shrugged?
Don't think I've ever seen him in before 13.00. I've handed plenty of trains to him though 😀
The quick cheap answer to the temperatures on the Central line is to dig cross tunnels to the old Post Office railway, adjacent at several locations and install fans. I've said it before several times but can't get anyone to listen. I know that Whitehall once had a plan to use it as an escape route in case of etc etc, but to hell with the lot of em!
The Post Office Railway opened as a tourist attraction last year.
I rode Mail Rail this summer. The route it uses isn't much more than doing a single loop from the depot, around Mount Pleasant and back to the depot again. This part of the Post Office Railway is the part furthest from the Central Line, I recall it being a fair walk to Chancery Lane to then go on to Stratford.
In the context of this thread, this was one of the hottest days of the year. Not much sooner had we got on the Central, did I want to get off due to the heat. It was crush loaded on a Saturday afternoon, and another passenger was carrying a take-away pizza! This was the same day that Bank was closed for investigating the platforms, so after braving it out past St Paul's, I had to stay on to Liverpool Street. Then we headed upstairs to catch a nice air-conditioned TfL Rail service to Stratford.
I don't know if the Central Line is the hottest, but it was certainly unbearable for me.
The map shows mostly an east-west alignment from Paddington to Whitechapel, but it heads north-east towards Mount Pleasant roughly at Holborn, then back south-east rejoining just west of St Paul's station. Reportedly, Crossrail construction has had to avoid it.
I suspect the idea of using this for ventilation founders on the problem that there are few vents to the surface. Most of the old sorting offices have been sold off - I don't think Bank of America Merrill Lynch, for example (who occupy the former King Edward Building Post Office near St Paul's), would be too keen on having a vent shaft put in. That one is also a listed building.
Also, for ventilation tunnels, you probably want a larger diameter bore so that you can have a large fan turning slowly (quietly, at low frequency), rather than a small one turning quickly (loud, easily audible frequencies). I've walked in ventilation tunnels constructed for the Victoria (at Euston) and Jubilee (at Charing Cross) which are more than twice the diameter, so over four times the cross-section.
A solution is required, I just don't think this is it.
I would have said that the Vic was the hottest on the platforms at least. As for general temperature... having all those illuminated adverts, TV screens and overhead projectors can't help the situation one tiny bit! Go back to reflective & passive advertising instead of transparent & active. PLEASE!!!