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Why do Victoria line trains not have air conditioning?

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bramling

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Why experimental tunnel? Was there a new tunnelling technique being used?

Yes. Mechanised tunnel boring machines as opposed to hand-worked shields, and different types of lining - pre cast concrete and unbolted cast iron. All this was effectively new to LT, although concrete lining had been used before.

The big benefit of tunnel boring machines is that they are quicker and don’t require grouting round the finished tunnel, but they are costly and take time to set up, so there is much value in getting things right. Naturally they are only viable when they can drive on for long distances, the Victoria Line being ideal for that.
 
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swt_passenger

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Why experimental tunnel? Was there a new tunnelling technique being used?
First general use of precast concrete segments I think. The tunnelling “shields” themselves were pretty standard, but I think the full rotating cutter head was a new thing.
 
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Can we not look to the Houses of Parliament to see how to expel huge amounts of hot air?

So true :E the Brexit negotiations are a good example of that. I still haven't forgotten THAT tweet from last summer about the Central line not getting new trains til 2030
 

Busaholic

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Why experimental tunnel? Was there a new tunnelling technique being used?
A 'drum digger' rotary shield was used, powered by hydraulic rams, according to Wikipedia. I've a copy somewhere of 'Building London's Underground' which would probably provide more info, so I could look it out if you express interest.
 

The Ham

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I was reading an article about renewable energy, it was talking about using solar energy to heat water to then heat rocks deep down (circa 150m down) so that the heat could be used at another time in the year.

That for me thinking, would it not be possible to use air source heat pumps to extract heat from the air in the underground when it's very hot to do the same?

With the heat then pumped back out of the deep rocks to warm the stations during the winter.

It would therefore solve a few problems in one go.
 

Mojo

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With the heat then pumped back out of the deep rocks to warm the stations during the winter.
Tube stations are already roasting hot in the winter. They don’t need any more heating, which would also make the trains even hotter.

There is already a scheme under construction in Islington to enhance a district heating scheme using waste air from the Northern line to heat and provide hot water to nearby flats
https://uk.ramboll.com/projects/ruk/heating-up-london
 

jon0844

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I've often thought, cost aside, air conditioning stations would make travel a lot more comfortable and maybe help bring down the ambient temperature on trains a little.

It would be the next best thing to cooling the trains themselves, if air conditioning isn't possible.
 

Meerkat

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Tube stations are already roasting hot in the winter. They don’t need any more heating, which would also make the trains even hotter.

There is already a scheme under construction in Islington to enhance a district heating scheme using waste air from the Northern line to heat and provide hot water to nearby flats
https://uk.ramboll.com/projects/ruk/heating-up-london

AIUI that link talks about blowing cold air down a mid tunnel ventilation shaft. Doesn’t that increase the pollution issues for passengers if the air is coming out of the dust filled tunnels rather than via the stations above?

The obvious answer is to shut the line every now and then and flush the line through with nice cool Thames water :lol:
 

Destia Tenny

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There's barely any room for it, and nowhere in the deep tunnels to vent the extracted heat.

The Deep Tube Upgrade stock (neé New Tube for London) is purported to have an air cooling system, but no details of how it might work have been made public.
My anecdotal information shows that a kind of coolant will be introduced to the a/c system and will be chilled by electricity when trains are running overground...but I still have no idea how future Victoria line trains on the all underground line
could be air-conditioned by this way...
 

Flying Snail

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I was reading an article about renewable energy, it was talking about using solar energy to heat water to then heat rocks deep down (circa 150m down) so that the heat could be used at another time in the year.

That for me thinking, would it not be possible to use air source heat pumps to extract heat from the air in the underground when it's very hot to do the same?

Air source heat pumps are essentially the same thing as AC units, just fitted in reverse to heat the interior of buildings.

Theoretically you could fit the roofs of station platforms with a large number of AC evaporator units, there is plenty of space there to fit them. The problems would be the length and number (2 per unit) of the insulated refrigerant lines you would need to run to the surface as well as the space to put the compressor side units at street level or above on the stations. If enough cooling was installed it at every station it would eventually daisy chain the entire network, the tunnels would cool down through the piston effect from the trains which would also cool down as would the rest of the station through the cool air slowly pushing the hot out through the escalator shafts.

The other issue (and probably the one TfL won't admit is the real reason they won't do it) is the cost, the amount of AC kit needed to be installed to achieve this and the ongoing electricity to run it would be huge.

With the heat then pumped back out of the deep rocks to warm the stations during the winter.

That is what has happened organically over the life of the tube, heat has seeped into the stations, tunnels and surrounding ground and this is what keeps the whole system permanently hot rather than the cold temperature that naturally exists below ground level which caused the tunnels to be cool year round as advertised in the early decades of operation.
 

Bald Rick

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Rather spookily, there has just been an item on the local news about the use of the old City Rd station on the Northern line to extract heat from the tube to be used for a district hearing scheme.
 

AM9

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Air source heat pumps are essentially the same thing as AC units, just fitted in reverse to heat the interior of buildings.

Theoretically you could fit the roofs of station platforms with a large number of AC evaporator units, there is plenty of space there to fit them. The problems would be the length and number (2 per unit) of the insulated refrigerant lines you would need to run to the surface as well as the space to put the compressor side units at street level or above on the stations. If enough cooling was installed it at every station it would eventually daisy chain the entire network, the tunnels would cool down through the piston effect from the trains which would also cool down as would the rest of the station through the cool air slowly pushing the hot out through the escalator shafts.

The other issue (and probably the one TfL won't admit is the real reason they won't do it) is the cost, the amount of AC kit needed to be installed to achieve this and the ongoing electricity to run it would be huge.



That is what has happened organically over the life of the tube, heat has seeped into the stations, tunnels and surrounding ground and this is what keeps the whole system permanently hot rather than the cold temperature that naturally exists below ground level which caused the tunnels to be cool year round as advertised in the early decades of operation.
It has also been exacerbated by the onward rise of power of the trains and their frequencies.
 

hwl

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It has also been exacerbated by the onward rise of power of the trains and their frequencies.
But also some what offset by the use of regenerative braking on newer tube stock.
 
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hwl

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Air source heat pumps are essentially the same thing as AC units, just fitted in reverse to heat the interior of buildings.

Theoretically you could fit the roofs of station platforms with a large number of AC evaporator units, there is plenty of space there to fit them. The problems would be the length and number (2 per unit) of the insulated refrigerant lines you would need to run to the surface as well as the space to put the compressor side units at street level or above on the stations. If enough cooling was installed it at every station it would eventually daisy chain the entire network, the tunnels would cool down through the piston effect from the trains which would also cool down as would the rest of the station through the cool air slowly pushing the hot out through the escalator shafts.

The other issue (and probably the one TfL won't admit is the real reason they won't do it) is the cost, the amount of AC kit needed to be installed to achieve this and the ongoing electricity to run it would be huge.



That is what has happened organically over the life of the tube, heat has seeped into the stations, tunnels and surrounding ground and this is what keeps the whole system permanently hot rather than the cold temperature that naturally exists below ground level which caused the tunnels to be cool year round as advertised in the early decades of operation.

The best solution for tube cooling (especially given lower ground water abstraction and rising water table) is probably bore hole ground sourced heat pump as the energy efficiency in this case will be as least twice as good as any air sourced set up. It also has the advantage of being capable of being fully independent of LU operations. Building could also use water extracted form boreholes for grey water use instead of returning it all. The CapEx would also be far far lower.
 

Chris M

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There was a trial of groundwater cooling at Victoria:
2007 TfL press release said:
London Underground's innovative groundwater cooling trial at Victoria station has been recognised with a prestigious Innovation Award by the Carbon Trust.
[...]
David Waboso, LU Director of Engineering, said: "Prior to Transport for London taking control of London Underground, attempts to try and cool the Tube were haphazard. We have now started a coordinated programme to understand the problem and to tackle heat on the Underground.

"The groundwater cooling trial at Victoria uses an available and sustainable energy source that has had a very noticeable impact in reducing temperatures on the Victoria line concourse and platforms.

"The trial which started last summer will continue throughout 2007. If it continues to provide good results then the technology will be rolled out to a number of other locations across the Tube network."
https://tfl.gov.uk/info-for/media/p...ing-trial-at-victoria-wins-carbon-trust-award
and something "more sophisticated" was installed at Green Park in 2012:
London Underground has already successfully drilled wells to source naturally cool water from deep below Green Park and will now install air cooling units that will use the water to cool the Victoria and Piccadilly line platforms.

https://www.ianvisits.co.uk/blog/20...be-station-to-get-groundwater-cooling-system/

I've not immdeiately found anything more recent than that tough - certainly nothing with great fanfare to suggest the trials were espeically succesful.
 

Bostwick

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Not sure I agree with the comparison. The Central line gets very hot as it is often packed but the Victoria line is stifling even when lightly loaded. When the Vic line new trains first came in it was worse and you'd see people at Walthamstow Central taking the second train out if it was old stock to have a more comfortable journey! The 'overheating' or lack of adequate air circulation was supposedly fixed which meant it was a bit better but it's still pretty unacceptable.

Yes, there is something odd about the Victoria line trains, even outside peak hours, lightly loaded conditions and when the outside temperature is cool the carriages are stifling hot. I have noticed in many carriages the metal panels below the seats are rather warm, it is like there are being heated. The air in the carriages has the same feel if you get on a bus in the Summer and the saloon heaters are still switched on. Do Victoria line trains have heaters and are they constantly jammed on?
 
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