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The Piccadilly line’s new air conditioned trains
- wdb 3y agoStill unclear why they didn't go for first replacing Central/Bakerloo triains
- buildstatements 3y agoYeh the central line is AWFUL. I used to travel out of my way to avoid it.
- kilroy123 3y agoI agree. I prefer to use the Elizabeth line whenever possible.
- chuckleMuscle 3y agoWasn't taking traffic off the central line a motivation from the start for Cross rail? This might be another reason why TFL is prioritising other lines over the central.
- tescocles 3y agoI feel sorry for the people that have to use it to commute every day. Surely their hearing must be being damaged.
- zeristor 3y agoFinance I guess. They’re working through a process of rebuilding Central line trains, updating virtually everything it seems.
- NeoTar 3y agoDoing five minutes research it seems that it's just down to the Piccadilly line being busier than the Bakerloo line - given that the Bakerloo being duplicated in parts by the London Overground. The Central line are on much more modern stock - the 1992 stock, and are currently undergoing a renovation programme, so the need to replace them is less pressing.
- fredoralive 3y agoCentral Line trains are 20 years newer, so presumably aren't going to be at the front of the queue. They do seem to be planning to do major refurbishment / upgrades on them in the near future, up to replacing the motors and related power control systems (DC to AC motors). Bakerloo line trains are about the same age of the Picadilly line, but the Bakerloo line is less used, so presumably that has edged the Picadilly ahead. They are next in line, as the article notes.
- masklinn 3y agoProbably because the NTfL studies forecasted much larger opportunities on Piccadilly (60% capacity increase versus 25 on central and bakerloo). So they prioritised deploying the new trains on Piccadilly. All three lines, and Waterloo & City, are planned for upgrade.
- kmlx 3y agohttps://www.ianvisits.co.uk/articles/look-out-on-the-central-line-an-upgraded-train-has-started-final-tests-67442/ https://www.ianvisits.co.uk/articles/look-out-on-the-central... coming soon
- emblaegh 3y agoThose are just refurbished current stock I believe, so likely will still have no air con.
- lawtalkinghuman 3y agoCentral Line is due next ~2030. Then Bakerloo: ~2033. It's kind of reasonable to deprioritise the Bakerloo, even as someone who used to use the Bakerloo very frequently. Bakerloo gets significantly less usage than other lines: Piccadilly has double the number of annual travellers than the Bakerloo, for instance. (It'll be interesting to see if Piccadilly usage numbers go down now Crossrail has been finished and some portion of Heathrow travellers switch over.) The Bakerloo itself is also kind of a weird, redundant line. The NW segment doubles up with the Watford DC line, and for a lot of NW destinations like Wembley, the Jubilee and Metropolitan are better choices. There was also the issue of the proposed extension out to New Cross and/or Lewisham. They probably wanted to put off making a decision on the rolling stock upgrade until after they'd decided whether they were doing the SE extension.
- te_chris 3y agoIn my exerpience, whatever traffic the Elisabeth line has diverted hasn't made a difference. Piccadilly line still busy - I live on it.
- gpvos 3y agoHasn't Crossrail also diverted many travellers from the Central line?
- _aaed 3y agoWarwick Avenue and Maida Vale are two important stations to the Bakerloo line in my opinion
- merth 3y agoair conditioned trains are an achivement in 2023?
- benjijay 3y agoAdding AC units to trains which travel through tunnels with minimal clearance is the achievement - Can't make the trains any bigger and there's no room in the old ones to just tuck an HVAC in without make them even more cramped.
- SideburnsOfDoom 3y agoAC units dump the heat "outside" into the air. There is no outside in deep tunnels. Nowhere for the heat to go. The tunnels have already heated up over the decades. https://en.wikipedia.org/wiki/London_Underground_cooling https://en.wikipedia.org/wiki/London_Underground_cooling It's not primarily about headroom.
- bluGill 3y agoHeadroom is not an issue - there is plenty of room underneath the trains between the wheels. They then pump the cooled air up through the walls to where they want vents. Sometimes trains use the space between the wheels for passengers, but that has significant disadvantages and so should be avoided for subways (it is worth it for street running trams!),
- thejsa 3y agoYes, given the size constraints of the deep-level Tube tunnels, which are much smaller than those for mainline trains; apparently developments in small air con systems have helped a fair bit here, fifteen odd years ago apparently it just wasn’t feasible.
- anonymous_sorry 3y agoArguable the more fundamental problem is this. Air-con is a negative-sum game because it not 100% efficient. As well as moving heat from one place to another, it creates extra heat. Turn air-con on in an enclosed space, with nowhere to vent the exhaust, and that space just gets hotter. A small, deep tunnel is close to being an enclosed space. You might be able cool the train interior a bit, but the tunnel will get hotter. Meaning the air-con has to work harder. Meaning it generates more heat. The Picadilly line is already uncomfortably hot for a good part of the year (but far from the worst [1]). This includes the platforms. What this article says is that the trains themselves are lighter and more efficient, so less heat is generated by the motors and brakes. They argue that that gives them some heat budget to use on air-conditioning. As a whole, the new trains will generate roughly the same amount of heat as the old ones. So the tunnels and platforms will stay around the same (ie, too hot!), but the train interior will be comfortable. [1] https://www.standard.co.uk/news/london/tube-underground-london-temperature-hottest-b1103973.html https://www.standard.co.uk/news/london/tube-underground-lond...
- Roark66 3y agoI read half way through that article and I still don't understand how did they manage to fit aircon on these trains. There were various ideas over the years including for the trains to carry ice, but none stuck. This time they finally develop ac "that doesn't emit heat outside" and they say nothing about how it works?
- vallode 3y agoIf I understand correctly, it is not about "not emitting heat", they reduced the natural output of heat of the trains and gave the excess allowance to the new AC system.
- Nextgrid 3y agoI wonder, are we now at equilibrium with the surrounding earth so the heat of the trains is now actually vented outside, or is the clay still absorbing heat? If it's the latter than this merely kicks the can down the road and ambient temperatures will keep rising.
- mannykannot 3y agoThe article is not quite explicit about that, but it does say "cooler running trains could help to cool the tunnels, but it would take decades to notice the difference, or they can use that temperature gap between the new and old trains to put air conditioning inside the carriages today... If a future plan to run even more trains through the tunnels goes ahead, that will require increased cooling in the stations, which, funding permitting, is being developed at the moment." The implication seems to be that an equilibrium (or something very close to it) has been reached for the current traffic volume (and putting aside climate change, presumably.)
- bluGill 3y agoThe earth is naturally at equilibrium with the average air temperature outside. (when you get really deep the earth's core makes a difference, but at these depths we can ignore that). However when you add heat like the tube does, the earth is enough insulation that it can be decades before it reaches equilibrium again. For purposes of this discussion clay should be seen only for the R-value. (absorbing heat is a very useful property of clay for other purposes, but in this discussion that is not relevant)
- onetimeuse92304 3y agoBut wouldn't this make the problem even worse? Air conditioning will dump even more heat into the tunnels.
- Symbiote 3y agoSee the 10th paragraph of the article.
- ocharles 3y agoFor those who won't bother to RTFA: the trains run cooler than other trains, so they are taking advantage of the difference such that the net result is the same temperature in tunnels, but the interior of trains can be cooler.
- onetimeuse92304 3y agoOh, so this is exactly like budgeting. It does not matter a lot how much something costs, what matters is where the money came from. Here we improve the trains to emit less heat and immediately spend it on air conditioning. In the meantime the debt (tunnel excess heat) continues to rise and somebody else in the future will have to pay for it.
- NamTaf 3y agoIt's more like budgeting at a home level, in that you have a set limit of heat that you can spend, and choosing to spend it less on equipment like brakes, traction motors, etc. and more on air conditioning means still remaining in budget. Their overall limit of heat output by the trains remains the same. The tunnels won't be any hotter than they are now, thanks to savings found in other systems.
- onetimeuse92304 3y agoNo, it is more like government spending. It is like saying, "we need to be fiscally responsible and that means only spending no more than 160% of what we are earning". The tunnels are getting hotter and hotter. Saying "the tunnels won't be any hotter" is completely unfounded in reality.
- the_mitsuhiko 3y agoI found it very funny to see these trains parked behind my house. I live in Vienna, but apparently some were assembled here.
- bluGill 3y agoScale factors in assembly are very important for both quality and low costs, so a few assembly lines around the world make sense for trains. Then ship them to where needed. I'm not sure if North America should have assembly lines, but politics means we do. Of course if the US ordered a lot of trains this would change, but a lot means that a line needs to be turning out several completed trains of this size per hour (it would be nice if world public transit was that popular)
- JAlexoid 3y agoUS does have assembly lines... You may underestimate the number of trains and rail cars that US needs. Just servicing NYC metro and commuter area would easily make a few assembly lines profitable.
- bluGill 3y agothe US does have them - but I'm not convinced we should - vs building them in say Germany and putting them on a ship. Yes assembly lines are profitable. However less assembly lines that produce more trains allows for efficiency from scale and thus could potentially be even more profitable while selling trains for less. NYC does not have a lot of trains. Sure they are in the thousands, but automotive assembly lines can turn out as many cars in a week as the whole US has. Trains also generally last for 40 years (the London trains in question are older than that). Note that the US has them because of "buy America" rules and not for good reason. Those rules likely increase the costs of trains.
- t43562 3y agoI wonder if future tube lines could have some sort of cooling system to pump heat into some underground reservoir in summer which could then be the source for a district heating system above ground in winter. I'm just wondering about how to make the problem a benefit.
- bradyat 3y agoThey do use the excess heat for some public buildings in Islington https://www.islington.media/news/bunhill-2-launch-pr https://www.islington.media/news/bunhill-2-launch-pr
- jayelbe 3y agoI never knew this existed before and can't help thinking it's absolutely incredible. Thanks for sharing!
- SideburnsOfDoom 3y agoThe ground around the deep tunnels already is a heat reservoir, over decades it heated up. https://en.wikipedia.org/wiki/London_Underground_cooling https://en.wikipedia.org/wiki/London_Underground_cooling
- t43562 3y agoThat is interesting because it suggests that we could grab some of that heat in winter and pump it into houses and businesses on the surface. In the long term that would help summer heat in the tube to be less of a problem.
- SideburnsOfDoom 3y agoThe idea of "Grab that heat and pump it into businesses and apartment blocks above" requires actual physical infrastructure, and so suffers from the same issues as drilling new ventilation shafts to simply vent waste hot air into the air above: It's a densely inhabited area, and has been for a long time. It is neither cheap nor easy to find room for those ventilation shafts, both below and above ground. If venting was easy, it would have been done long ago, well before the idea of re-using waste heat rather than just venting it was a thing.
- baz00 3y agoThe Piccadilly line is known as The Tandoor in some parts of London, hopefully no more!
- oblio 3y agoNot 100% sure I get it, I assume because it gets very hot and I guess, has a strong odor?
- AlecSchueler 3y agoIt's like an oven, there's not much more to it than that.
- baz00 3y agoIt's really hot, you get plastered to the inside of the doors when it's busy and goes through Hounslow which is where the Indian population is in London. They named it that themselves and it caught on.
- r0bbbo 3y agoI lived in Hounslow for thirty years and got the Piccadilly Line daily. I never once heard it referred to as The Tandoor.
- baz00 3y agoLived there for 20 years and heard it regularly. Did you have headphones on for 30 years on it? :)
- r0bbbo 3y agoNo. And a quick search finds possibly one mention of it from 9 years ago on Reddit. It's not widely used.
- robga 3y agoLiving in zone 6 where the underground is overground, it’s more like Jalfrezi at this time of year.
- disruptiveink 3y agoThe issue is that a major point of this upgrade was defeated as the article slightly mentions, but doesn't dwell on it: the signalling upgrade that the line sorely needs was axed during the Covid TfL budget crisis negotiations and is not coming back. The whole point of the "New Tube for London" project was that new modern trains were tied to signalling upgrades, which would let more trains run on the existing lines in a more reliable way. The trains were already ordered so will be delivered, with the associated flashy benefits of new carriages, but now the line capacity won't increase, so you'll still get the same breakdowns and delays that currently happen now. The Piccadilly line also won't be able to stop at the stations it currently skips (since they don't want to delay service any further than now) – making the Piccadilly Line stop at some of the stations it currently skips was also tied to the signalling upgrades. It's classic top-down "you need to cut on costs" decision making leading to having to make compromises on a project in a way that it'll still cost a bunch of money, but without a major benefit at the expense of a (comparatively) small cost saving. You see this in software engineering all the time too.
- martinald 3y agoThis isn't completely correct. There is going to be an increase of capacity even without resignalling from 24tph to 27tph. It's also not a low cost thing, the SSLs resignalling cost at least £1.6bn and has been horrendously delayed. While the pic line is less complex than the SSLs, there has been ridiculous cost inflation on all rail projects, so I would not be surprised if it costs a similar amount of money. In comparison the new trains cost £1.5bn so it's basically the same again to resignal the line to ATO. I also believe the new trains can accelerate faster so new stops are potentially possible. And in theory at least they should be a lot more reliable, even if the signals aren't. FWIW there was a signals redesign contract for the pic singed in 2022 so I don't think it's never going to happen. Also even before covid it was phased that the new trains and signalling where fairly independent projects.
- blackhaz 3y agoI was amazed how well underground trains accelerate in Amsterdam and Munich. Also, how pleasant they are, and the interior design pleasantly fresh, with good amount of space and good-sized windows. That tube stock we have from the 70s looks really, really dated in 2020s. And the new ones look exactly the same, just even smaller windows? I can't imagine why they went ahead with that purchase.
- JCM9 3y agoCooling the trains is a relatively easy problem to solve these days. It’s cooling the tunnels and stations that’s the true engineering challenge.
- rob74 3y ago...especially with such cramped stations and tunnels as the London tube!
- the_other 3y agoThe linked article touches on this. It explains that the new trains emit similar heat levels to older trains, and says there was no option to emit more heat without heating the tunnels. They made the running gear cooler (by installing less of it), and using that heat saving as the budget for the air cooling. As a software engineer who's not touched hardware design in 25 years, I found this heat budgeting really interesting.
- droopyEyelids 3y agoIf you're the kind of person who plays video games, you might enjoy Oxygen Not Included, managing heat is one of the game mechanics
- Cthulhu_ 3y agoAs is oxygen and waste; I never thought of it as an analog to the same problems that the tube has.
- droopyEyelids 3y agosame problems as life on planet Earth!
- rtkwe 3y agoWith the convenience of thermodynamically impossible heat deletion mechanics though. Steam turbines in that game delete heat for every bit of energy they produce.
- jwmoz 3y agoIf anyone from TFL is reading this, for the love of God please do the Victoria line next.
- NamTaf 3y agoI'd far prefer them to do something about the ungodly flange squeal - TfL, grind your tracks!!! That's way more of a clear and present health risk to me than the heat.
- quietbritishjim 3y agoI hate to break it to you but Victoria line modernisation, including cooler trains, has already happened in 2009. Here's an example IanVisits article about that: https://www.ianvisits.co.uk/articles/today-marks-the-final-trip-of-the-67s-on-the-victoria-line-4709/ https://www.ianvisits.co.uk/articles/today-marks-the-final-t...
- nsteel 3y agoAnd you can tell. The Victoria line is way more comfortable than the three lines getting an upgrade that are all hellish, all your round.
- xkekjrktllss 3y agoCarpet never belongs on city trains. How does this keep happening?
- Cthulhu_ 3y agoWhere are you seeing carpet? Looks like vinyl or linoleum to me. Or do you mean the upholstery?
- fortran77 3y agoIt’s nice to be able to go to Cockfosters in comfort.
- a_c 3y agoWill it get any quieter, though? And why can't we get rid of the moquette, they get disgusting quickly.
- dyerjohn 3y agoI love how British articles have no problem using words like "Moquette" Does everyone in Great Britain know the definition? https://en.wikipedia.org/wiki/Moquette https://en.wikipedia.org/wiki/Moquette
- lotsofspots 3y agoI can't remember a time when I didn't know the word, but then I grew up near London so used the Tube regularly as a child.
- coremoff 3y agoNo, but anyone who has used the tube or busses more than a couple of times will know exactly what they're talking about when they see the pictures of the seats associated with the word.
- lsllc 3y agoCheck out Geoff Marshall's video with a real life Tube moquette designer (Paul Marchant): https://www.youtube.com/watch?v=cAJrfL6loC8 https://www.youtube.com/watch?v=cAJrfL6loC8
- switch007 3y agoIt's that disgusting fabric found on the Tube that when you slap it, you can see a plume of dust and god knows what else
- virtualritz 3y agoThe real issue is the excess heat from losses (breaking, mechanical etc.) [1]. This heats the stone of the tunnels since the tube was built. The heat can't dissipate fast enough. The tunnels get hotter every year. Because of this the tube has gone from a cool place you escape to in summer, in the early 19th century, to a place you'd look for warmth in winter. And a sauna in summer. Any air-conditioning system that produces excess heat as a side effect will make this worse. Even if the passengers on those trains will feel it less. [1] https://www.wikipedia.org/wiki/London_Underground_cooling https://www.wikipedia.org/wiki/London_Underground_cooling
- kwhitefoot 3y agoCan't this be regarded as an opportunity instead of a problem? Sink a few shafts and use heat pumps to extract the heat to a district heating system.
- SideburnsOfDoom 3y agoIf it was logistically easy to sink air shafts, it would have been done a long time ago, just to vent hot air, long before also using that heat was an idea. It's a densely built up area. Space above and below ground is hard to find.
- maherbeg 3y agoI wonder if they could bore some geothermal loops to move the heat someplace else to dissipate more easily.
- eesmith 3y agoBeing done. https://www.ianvisits.co.uk/articles/cooling-the-tube-engineering-heat-out-of-the-underground-20873/ https://www.ianvisits.co.uk/articles/cooling-the-tube-engine... (from 2017, 59 HN comments from 2022 at https://news.ycombinator.com/item?id=31694445 https://news.ycombinator.com/item?id=31694445) says > Elsewhere, they’ve been using cool groundwater to cool some of the stations. An experiment at Victoria station was the first, as water from the River Tyburn was used to cool the air in the station. This was only an experiment, but at Green Park, a permanent version was installed in 2012. > There, five boreholes were drilled deep down into the ground, and here cool water is sucked up to the surface, used to cool a separate water supply which is pumped down to cool the platforms, and the warmed groundwater is also pumped back into the ground.
- RichardCA 3y agoWas the subject of a classic Monty Python bit in one of their books in the 70's. https://greatwen.com/2012/11/20/how-to-take-your-appendix-out-on-the-piccadilly-line/ https://greatwen.com/2012/11/20/how-to-take-your-appendix-ou...
- InTheArena 3y agoA video tour: https://www.youtube.com/watch?v=mlP9cJOHEEc https://www.youtube.com/watch?v=mlP9cJOHEEc
- m463 3y agoDoes anyone understand the multi-gauge track in the picture titled: "An unusual view from the front of a Piccadilly line train" it seems pretty fascinating.
- Symbiote 3y agoThe other rails are the electric supply, 19th century style.
- lsllc 3y agoHere's Geoff Marshall's take on the new trains: https://www.youtube.com/watch?v=mlP9cJOHEEc https://www.youtube.com/watch?v=mlP9cJOHEEc
- Osiris30 3y agoThe biggest question I have is why does it take 47 years to upgrade trains in one of the richest cities in one of the richest countries in the world?
- LAC-Tech 3y agoHaven't you seen 'Yes, Minister'? But in all seriousness I can't imagine all the layers of un-elected, unaccountable bureaucratic petty power centres a mere elected official would have to navigate to get anything done in London. It's the same in all westminster democracies - I'm from New Zealand and it's projected to take 10 years to make a 3.5km/2.2mi underground rail tunnel in our largest city. Let's be optimistic and say it's only 4 years late - that'd be a bit over half a yard/metre of tunnel per day.
- wackget 3y agoWhy do they continue to use fabric for the seats? Fabric and foam gets insanely dirty and is almost impossible to properly clean. There's also the very real problem of bedbugs being spread via the tube.
- sexy_seedbox 3y agoHong Kong MTR does it well, metal seats, easy to clean