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Post by holborncentral on Jun 29, 2018 23:35:57 GMT
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Post by Deleted on Jun 29, 2018 23:44:08 GMT
Well of course it's legal, nobody's forcing people to get on, there are opportunities for us to get off every couple of minutes and we can take a bottle of water with us |
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Post by superteacher on Jun 30, 2018 6:08:29 GMT
Perhaps it should be illegal to live in countries where the temperatures exceeds 35C?  The only time it ever becomes an issue is when there is a service disruption causing trains to be stuck in tunnels. There have been some potentially serious incidents over the years, notably on the Victoria line when quite a few people had to be treated for the effects of heat. |
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Post by stapler on Jun 30, 2018 7:22:31 GMT
The 92TS has exacerbated things, IMO. The 62s had head height ventilators through the cabs, whereby a rush of air was forced through the driving motor cars. There is now a dead end, a repository of hot, humid, stagnant air at the end of every DM - in one of which I had to sit between Liverpool St and Stratford the other day.
Also, the windows in the end of every car are "stopped" too high up.
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Post by superteacher on Jun 30, 2018 7:37:09 GMT
What the article doesn’t mention is the greenhouse style windows which allow the temperature inside the train to rocket in the open air. This means that there is little or no opportunity for them to cool down. They fitted a type of film to the windows a couple of years ago to mitigate this, but I’ve no idea how successful it has been.
Modern trains also generate a lot more heat than their predecessors.
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Post by roman80 on Jun 30, 2018 8:14:17 GMT
What are the reasons the trains can't stable overnight with the doors open?
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Post by aslefshrugged on Jun 30, 2018 8:33:36 GMT
What are the reasons the trains can't stable overnight with the doors open? 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. |
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Post by superteacher on Jun 30, 2018 14:39:22 GMT
What are the reasons the trains can't stable overnight with the doors open? 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? |
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Post by Chris M on Jun 30, 2018 14:56:28 GMT
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Post by londoner on Jun 30, 2018 19:01:41 GMT
Do the new trains for the Picc line have air conditioning? If so, and if therefore the same trains are used for the central line, I don't understand the last sentence:
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Post by Deleted on Jun 30, 2018 20:34:35 GMT
Do the new trains for the Picc line have air conditioning? If so, and if therefore the same trains are used for the central line, I don't understand the last sentence: Where was that said?. If it was posted before the new pic train announcement, the air conditioning had not yet been confirmed. |
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Post by aslefshrugged on Jul 1, 2018 0:49:02 GMT
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? I've hardly used an alarm clock for seven years and since the introduction of WTT 69 I've rarely started before 15:00. Civilised |
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Post by londoner on Jul 1, 2018 8:35:50 GMT
Do the new trains for the Picc line have air conditioning? If so, and if therefore the same trains are used for the central line, I don't understand the last sentence: Where was that said?. If it was posted before the new pic train announcement, the air conditioning had not yet been confirmed. I presume this means some sort of air conditioning system, as has some other media outlets, though I am not exactly sure what "saloon air-cooling" actually refers to.: www.railmagazine.com/news/network/siemens-wins-94-train-deep-tube-orderAdmittedly however, I think TfL have worded it in such a way (i.e. ambiguous) that it may not be a conventional air conditioning system but rather an attempt to improve the air flow or reduce the heat created by the trains. Speculation: This may be because they want to avoid telling people its an air conditioning system until they have a working product. |
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Post by Deleted on Jul 1, 2018 17:41:15 GMT
Where was that said?. If it was posted before the new pic train announcement, the air conditioning had not yet been confirmed. I presume this means some sort of air conditioning system, as has some other media outlets, though I am not exactly sure what "saloon air-cooling" actually refers to.: www.railmagazine.com/news/network/siemens-wins-94-train-deep-tube-orderAdmittedly however, I think TfL have worded it in such a way (i.e. ambiguous) that it may not be a conventional air conditioning system but rather an attempt to improve the air flow or reduce the heat created by the trains. Speculation: This may be because they want to avoid telling people its an air conditioning system until they have a working product. I thought I had read air conditioning somewhere official  |
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Post by Dstock7080 on Jul 1, 2018 18:47:26 GMT
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Post by superteacher on Jul 1, 2018 19:48:32 GMT
I always thought that air con was a non starter on the tube lines due to the heat generated. This would make the line even hotter than it already is (except inside the trains!)
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Post by countryman on Jul 2, 2018 5:03:25 GMT
There was a question on QI about whether you could cool a room by opening an operating fridge door. The answer was that it would not as the energy input is required to supply the chilling. By the laws of thermodynamics, a 100% efficient fridge would make no difference as the cooling effect of the open compartment would be in equilibrium with the heat output of the coils on the back. As the fridge could never be 100% efficient the heat output would always exceed the cooing effect, The only way for it to work is to take heat from one place and to emit it elsewhere. This is what happens in an air conditioning unit, whether it be in a building, a car or a train. So, yes, aircon in a tube train will heat the tunnels and make things worse. It will be OK in open sections, but there will be a miniscule contribution to global warming!
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Post by Chris M on Jul 2, 2018 10:44:06 GMT
That is unless the heat can be stored somewhere onboard and ejected later - which is tricky but probably not impossible.
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Post by brigham on Jul 2, 2018 11:56:06 GMT
Would cooling the air entering the underground portion be a more practical idea than cooling individual cars?
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Post by alpinejohn on Jul 2, 2018 12:06:30 GMT
Does the Central still use air operated points or other equipment?
I ask because I suspect it did in the past and there may well be some metal now redundant pipework still running alongside the tunnel walls. So how about sending chilled water down those pipes to perhaps take the edge of the otherwise inevitable climb in temperature.
As others have stressed to cool down those tunnels you need to transfer that heat energy elsewhere - perhaps the answer is to simply extract water from the Thames (or other river) - pump it through those abandoned pipes and eventually dump the now warmed up water back into some suitable water course. Yes the water will be a bit warmer but otherwise it should still be basically the same water quality as extracted earlier so should not create issues with Thames Water.
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Post by xplaistow on Jul 2, 2018 15:04:37 GMT
As others have stressed to cool down those tunnels you need to transfer that heat energy elsewhere - perhaps the answer is to simply extract water from the Thames (or other river) - pump it through those abandoned pipes and eventually dump the now warmed up water back into some suitable water course. Yes the water will be a bit warmer but otherwise it should still be basically the same water quality as extracted earlier so should not create issues with Thames Water. There could also be the potential with a scheme like this to find some use for the excess heat. I think I remember reading on IanVisits about a new housing estate that's heated by the Northern line. |
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Post by John Tuthill on Jul 2, 2018 15:26:30 GMT
As others have stressed to cool down those tunnels you need to transfer that heat energy elsewhere - perhaps the answer is to simply extract water from the Thames (or other river) - pump it through those abandoned pipes and eventually dump the now warmed up water back into some suitable water course. Yes the water will be a bit warmer but otherwise it should still be basically the same water quality as extracted earlier so should not create issues with Thames Water. There could also be the potential with a scheme like this to find some use for the excess heat. I think I remember reading on IanVisits about a new housing estate that's heated by the Northern line. Not forgetting that the Churchill Estate in Pimlico, was heated by the waste heat from Battersea Power Station. |
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Post by davethewomble on Jul 2, 2018 15:45:34 GMT
As others have stressed to cool down those tunnels you need to transfer that heat energy elsewhere - perhaps the answer is to simply extract water from the Thames (or other river) - pump it through those abandoned pipes and eventually dump the now warmed up water back into some suitable water course. Yes the water will be a bit warmer but otherwise it should still be basically the same water quality as extracted earlier so should not create issues with Thames Water. There could also be the potential with a scheme like this to find some use for the excess heat. I think I remember reading on IanVisits about a new housing estate that's heated by the Northern line. Was there not an experiment a few years ago in using ground water from the surrounding earth to cool Oxford Circus station? |
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Post by norbitonflyer on Jul 2, 2018 17:10:47 GMT
There could also be the potential with a scheme like this to find some use for the excess heat. I think I remember reading on IanVisits about a new housing estate that's heated by the Northern line. Not forgetting that the Churchill Estate in Pimlico, was heated by the waste heat from Battersea Power Station. The scheme started in 1950. However, housing estates last rather longer than power stations. The power station closed in 1983, but as the estate still needs to be kept warm (well, maybe not today!) a new boiler house had to be built to replace the waste heat previously generated for free by the power station. Indeed, those boilers were themselves replaced as life-expired in 2006. Modern power stations usually have better thermal efficiency, so produce less waste heat in the first place, and are usually in more remote locations where they won't overwhelm the locality*, so there would be bigger losses in transporting the waste heat anywhere useful. *I don't think many people realise how puny the London power stations were in comparison with modern ones. Drax Power station in Yorkshire covers about a square mile - if plonked on the site of Battersea Power station, its would extend over the entire Nine Elms area, almost all the way to the Oval. Drax's chimney is 850 feet high - taller than any building in London except the Shard. Drax produces 3960MW, (Battersea at its peak was 500MW) |
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Post by croxleyn on Jul 2, 2018 21:21:45 GMT
A year ago, the IET gave a fascinating talk about Cooling the Tube by Sharon Duffy, Head of Station Systems Engineering, LU Crossrail and Stations. If I remember correctly, we were told how cooled air is blown into some tunnels by "chimney" ducts along the lines. Asked about whether groundwater or The Thames (my question!) could act as a heat sink, the rules about what can be done are incredibly strict, so severely limiting these options. In essence, since the tunnels were dug, we've been feeding heat into the surrounding ground by all the traction/braking, escalators and lighting, not forgetting that an average human dissipates something like 100Watts, so there's a massive source of energy to fight against.
There are phase change materials that can absorb a large amount of heat, somewhat like ice melting to water, but the volume of material required in a train's aircon system would not be small: the heat would then be pumped out when the train was out of the tunnel. No use for the Victoria line!
It's not easy to cool within a tunnel: when chilling, the warm air will release significant amounts of condensate water, which has to be disposed of.
When Platform Edge Doors are used, I don't know if the new ones for The Elizabeth Line go right to the ceiling? In this way, the trains are more effective pistons carrying outside air along the tunnels in the direction they're travelling. Otherwise, the cross-tunnels of the stations allow air just to circulate from the previous station. But I guess PEDs would cause a different set of pneumatic problems.
Hyperlink: www.theiet.org/events/2017/244447.cfm |
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Post by gals on Jul 2, 2018 22:23:22 GMT
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Post by jetblast787 on Jul 3, 2018 14:19:20 GMT
An idea I had recently was to install extractor fans above the platform just over the doors of the train so hot air is forcefully sucked out and vented through pipes above the escalator barrels, allowing at least some airflow to occur. Quite radical and problematic (ie. the fans may be noisy or emit more heat), but it is an idea worth exploring. Even at some stops this could maintain some level of comfort. An example of this is the Central Line at White City when you can literally feel warm festered air inside the car escape into the outdoors once the doors open. The canopy also probably doesn't help...
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Post by superteacher on Jul 3, 2018 15:52:20 GMT
An idea I had recently was to install extractor fans above the platform just over the doors of the train so hot air is forcefully sucked out and vented through pipes above the escalator barrels, allowing at least some airflow to occur. Quite radical and problematic (ie. the fans may be noisy or emit more heat), but it is an idea worth exploring. Even at some stops this could maintain some level of comfort. An example of this is the Central Line at White City when you can literally feel warm festered air inside the car escape into the outdoors once the doors open. The canopy also probably doesn't help... How about extractors which forcibly suck out the passengers?  |
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Post by jetblast787 on Jul 3, 2018 18:14:59 GMT
An idea I had recently was to install extractor fans above the platform just over the doors of the train so hot air is forcefully sucked out and vented through pipes above the escalator barrels, allowing at least some airflow to occur. Quite radical and problematic (ie. the fans may be noisy or emit more heat), but it is an idea worth exploring. Even at some stops this could maintain some level of comfort. An example of this is the Central Line at White City when you can literally feel warm festered air inside the car escape into the outdoors once the doors open. The canopy also probably doesn't help... How about extractors which forcibly suck out the passengers? That's what the hyperloop is for  |
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Post by stapler on Jul 4, 2018 7:05:17 GMT
Cooling on the Central Line for use in the open sections would be appropriate, even if it had to be switched off in deep tunnels. Use in the open sections would cool the cars sufficiently to give a head start in the tunnel sections.
Also, where shafts exist, they should be kitted out with proper cooling equipment. Think I read somewhere that was intended between Liv St and Stratford in the 1946 extension, and between Leytonstone and Newbury Pk, but never fully done? Can anyone confirm?
Also, could the 92s not be retro fitted with air scoops over/through the cabs?
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