[HN Gopher] The Piccadilly line's new air conditioned trains
___________________________________________________________________
The Piccadilly line's new air conditioned trains
Author : edward
Score : 178 points
Date : 2023-11-21 12:07 UTC (10 hours ago)
(HTM) web link (www.ianvisits.co.uk)
(TXT) w3m dump (www.ianvisits.co.uk)
| wdb wrote:
| Still unclear why they didn't go for first replacing
| Central/Bakerloo triains
| buildstatements wrote:
| Yeh the central line is AWFUL. I used to travel out of my way
| to avoid it.
| kilroy123 wrote:
| I agree. I prefer to use the Elizabeth line whenever
| possible.
| chuckleMuscle wrote:
| Wasn'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 wrote:
| I feel sorry for the people that have to use it to commute
| every day. Surely their hearing must be being damaged.
| zeristor wrote:
| Finance I guess.
|
| They're working through a process of rebuilding Central line
| trains, updating virtually everything it seems.
| NeoTar wrote:
| Doing 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 wrote:
| Central 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 wrote:
| Probably 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 wrote:
| https://www.ianvisits.co.uk/articles/look-out-on-the-central...
|
| coming soon
| emblaegh wrote:
| Those are just refurbished current stock I believe, so likely
| will still have no air con.
| lawtalkinghuman wrote:
| Central 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 wrote:
| In my exerpience, whatever traffic the Elisabeth line has
| diverted hasn't made a difference. Piccadilly line still busy
| - I live on it.
| gpvos wrote:
| Hasn't Crossrail also diverted many travellers from the
| Central line?
| merth wrote:
| air conditioned trains are an achivement in 2023?
| benjijay wrote:
| Adding 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 wrote:
| AC 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
|
| It's not primarily about headroom.
| bluGill wrote:
| Headroom 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 wrote:
| Yes, 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 wrote:
| Arguable 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-
| lond...
| SideburnsOfDoom wrote:
| Yes, "Where to vent the waste heat" is 100% the fundamental
| problem. You can't beat the second law of thermodynamics.
|
| The tunnels have absorbed heat over the decades, venting
| yet more heat into the tunnels is not going to work.
|
| More space would make the engineering easier, but it's not
| the fundamental issue.
| londons_explore wrote:
| London underground runs in a parallel universe where they are
| reinventing 60's tech.
|
| They only recently got cell service for example. 20 years after
| most of the rest of the worlds railways.
|
| Some lines don't even have that yet either!
| kmlx wrote:
| the london tube dates from 1863. that explains most issues.
| walthamstow wrote:
| Of all the things TFL could do to improve the tube, cell
| service would not even be close to top of my list. We've had
| WiFi on the platforms for about 10 years which is enough to
| send/receive whatsapp messages while the train is stopped.
|
| I'm not sure it's fair to dig out TFL for being backwards.
| They introduced the Oyster in 2003, something NYC didn't get
| until 2019.
| londons_explore wrote:
| Reliable comms everywhere allows fully centralized train
| control, with no employees on each train. You can use
| cameras to check no passengers are stuck in doors, on the
| track, or fighting in the carriages or platforms.
|
| Now you can redeploy the staff away from repetitive tasks
| of driving trains and supervising stations, and towards
| engineering a better service. Get the typical journey speed
| up from 12 mph up to 45 mph. Make one direction of all
| tracks an express route that only stops at one station in
| 10 and drives 60 mph through all the others. Modify the old
| tunnels with an extra rail on a wall or ceiling for places
| where the tunnel alignment can't do 60 mph.
| walthamstow wrote:
| Are you a railway engineer or in some other related
| field?
|
| Some of these suggestions sound a bit bizarre to a
| layman, especially considering your idea that the only
| thing standing in our way is 4G signal and reshuffling
| some staff.
|
| > Get the typical journey speed up from 12 mph up to 45
| mph.
|
| So instead of 30 minutes from Walthamstow to Brixton
| it'll be 8 minutes? How is that possible?
|
| There are 16 stations, or 14 stops excluding the
| terminii. If you stop for 30secs at each, that's 7
| minutes in itself.
|
| > Make one direction of all tracks an express route that
| only stops at one station in 10 and drives 60 mph through
| all the others
|
| So we would have an express lane in one direction and a
| stopping lane in the other? Why is that a good thing?
|
| To me an express service seems /slower/ than the status
| quo, because I would have to wait longer for the train
| that stops where I want it to.
| londons_explore wrote:
| > So we would have an express lane in one direction and a
| stopping lane in the other? Why is that a good thing?
|
| Simulate it and see...
|
| Turns out that despite most users needing to make more
| changes, they will complete their journey far faster. The
| few journeys that are not completed faster (eg. taking
| the tube one stop) tend to either be walking distance or
| have an equivalent bus.
|
| Combine it with the fact there are multiple routes from A
| to B and there are many people who can take the fast
| train in both directions.
|
| For the railway operator, the trains are a big capital
| and operational cost. If you can make the trains run
| faster, you can get better utilisation of the seats, and
| therefore extra capacity/revenue. That more than
| outweighs the extra maintenance and electricity costs of
| going faster.
| londons_explore wrote:
| > So instead of 30 minutes from Walthamstow to Brixton
| it'll be 8 minutes? How is that possible?
|
| > There are 16 stations, or 14 stops excluding the
| terminii. If you stop for 30secs at each, that's 7
| minutes in itself.
|
| Or... you could stop at only 6 of the stops (express
| service). You could stop for 15 seconds door-open-time
| (as long as the crowd waiting for the train entirely fits
| on the train, thats very achievable - and crowd control
| can be managed by controlling platform ingress). Busses
| often achieve 3 seconds of door open time for comparison.
|
| At a top speed of 60 mph, max acceleration of 0.2g, max
| jerk of 3 m/s^3 and travel distance of 2 miles per stop,
| the whole travel time becomes 13 minutes. Plus the 1.5
| minutes for stops. =14.5 mins = 49 mph.
|
| Lets schedule in one 30 second slowdown (ie. drunk guy
| holds door for mate for 30 seconds), and the average
| speed hits the 45 mph target.
|
| I suspect the victoria line, being more modern in its
| track alignment, could easily be made to go 100 mph
| too...
| walthamstow wrote:
| Ok, so your big plan for quadrupling the speed of the
| tube is for trains to breeze through most stations
| without stopping. It's like amputation as a weight-loss
| tactic.
| cjrp wrote:
| Just having accurate next-train-arrival boards on each
| platform is a huge win, and not something every other
| subway system seems to have.
| Nextgrid wrote:
| That Wi-Fi is unusable. Not only does the association &
| DHCP negotiation take a large part of the time the train
| spends stopped at the station, but there's a stupid captive
| portal that also wastes whatever valuable time & bandwidth
| you manage to get despite the other issues.
|
| I've been travelling to places where conventional mobile
| service is available in the subway and it's such an
| improvement. Being able to look at maps, message or browse
| the net is a godsend especially as a tourist in a foreign
| country.
| jjgreen wrote:
| That's a feature not a bug.
| globular-toast wrote:
| The slight problem there is none of the rest of the world's
| railways are in London.
| bombcar wrote:
| Air conditioning a train in a tunnel is a trick, because the
| tunnels heat up and can't dissipate heat well at all.
| masklinn wrote:
| I don't know if you've been to london, but if you're a standard
| "modern" height for a man you can barely to not even stand
| straight in the deep tube trains. They are very _very_ small,
| and limited by the tunnels which are absolutely tiny. I'm not
| surprised fitting air conditioning is a challenge, even
| ignoring the ventilation issues which are also massive.
| kmlx wrote:
| a consequence of having the first subway in the world i
| think.
| sofixa wrote:
| Yep, same as many other things we take for granted in
| modern constructions, such as accessibility, good signage,
| enough space on stations and tunnels for easy flow of
| passengers, platform screen doors, etc.
|
| It's a no brainer when building today, but wasn't back
| then, and retrofitting is extremely complex and expensive.
| rwmj wrote:
| Dug "by hand": https://hornseyhistorical.org.uk/piccadilly-
| line-extension-p... https://en.wikipedia.org/wiki/Tunnellin
| g_shield#Manual_shiel...
| arethuza wrote:
| You should see the Glasgow Subway - its trains are almost
| comically small.
| jjgreen wrote:
| The entire network is a single line which circles the city,
| the map shows 2 lines, one clockwise, one anticlockwise.
| The trains have a dirty orange livery, hence the local
| name: The Clockwork Orange.
|
| My favourite underground in the UK.
| Nextgrid wrote:
| It's a huge achievement considering both the technical
| challenges (which other comments explain) but also that
| _anything_ actually got done considering the UK 's economic and
| political disaster.
| kmlx wrote:
| > UK's economic and political disaster.
|
| i really don't understand where this myth is coming from. do
| people seriously think the UK is an "economic disaster"?
|
| https://data.worldbank.org/?locations=DE-GB-FR
|
| and here are the numbers for 2023:
| https://commonslibrary.parliament.uk/research-
| briefings/sn02...
| walthamstow wrote:
| I don't think it's a myth. The UK is actually two
| economies. It's basically southern Italy with NYC bolted
| onto it. The average numbers like those you've posted
| include London and look basically OK, but the London effect
| is hiding a lot.
|
| Take out London and the rest of the UK is an economic
| basket case with low education levels, high rents, rapidly
| aging citizens, low wages, low investment, low
| productivity, a small tax base and a public estate in poor
| condition.
|
| This was a really interesting piece on the matter, in fact
| most of Murdoch's work for the FT is excellent
|
| https://www.ft.com/content/e5c741a7-befa-4d49-a819-f1b0510a
| 9...
|
| If you don't have a way to access the FT, this chart
| encapsulates my point quite well
|
| https://www.ft.com/__origami/service/image/v2/images/raw/ft
| c...
| TheOtherHobbes wrote:
| London itself is very divided. There's plenty of money in
| a few select areas, but wastelands of poverty around
| them.
|
| The UK has a huge reservoir of natural talent which it's
| doing its best to destroy. Plastic populism suits the
| ruling class much better than invention and originality.
| SideburnsOfDoom wrote:
| > There's plenty of money in a few select areas, but
| wastelands of poverty around them
|
| You can find the wealth and the poverty very close by,
| even at the same London address. i.e. a flats with huge
| book value, privately owned; and rented out to struggling
| people who will never be able to afford to buy their own
| flat.
| toyg wrote:
| _> It 's basically southern Italy with NYC bolted onto
| it._
|
| More like "basically Romania with Vlad Tepes bolted onto
| it". The London-driven finance-first economy (to which I
| partake, btw) inevitably sucks the blood out of the rest
| of the country.
| dukeyukey wrote:
| To be fair London is 13% of the UK's population, whereas
| Munich is a little under 2% of Germany's, I'm not
| surprised Germany's output stays the same!
| Karellen wrote:
| https://en.wikipedia.org/wiki/2021%E2%80%93present_United_K
| i...
| chilmers wrote:
| Well fortunately New Tube for London (this new train design)
| all got signed-off a decade ago. Buuuuuut, TFL only bought
| the trains necessary for the Piccadilly line, with "options"
| to buy trains later for the other lines. However, post-Covid
| they don't have enough money to buy them anymore, and would
| need the government to pay for them, which it likely won't.
| So I won't be holding my breath for any further improvements
| :-(
| globular-toast wrote:
| > but also that anything actually got done considering the
| UK's economic and political disaster.
|
| It's London...
| bowsamic wrote:
| Here in Hamburg the S-Bahns are only just being replaced by air
| conditioned models. I don't think there are even plans for an
| air conditioned U-Bahn yet
| anonymous_sorry wrote:
| It's best to read the article to understand why.
| SideburnsOfDoom wrote:
| Where would the waste heat go? Air Conditioning units dump the
| heat "outside" into the air. But there is no "outside" in deep
| tunnels. Worse, Air Con has to work to move heat, which creates
| more heat. You can't even break even. See the 2nd law of
| Thermodynamics.(1)
|
| It's not so much "air con on trains" but "air con in deep
| tunnels without a vent". There is nowhere for the heat to go,
| and the tunnels have already warned up over the decades. (2)
|
| > Conventional air conditioning was initially ruled out on the
| deep lines because of the lack of space for equipment on trains
| and the problems of dispersing the waste heat these would
| generate.
|
| Every solution is a costly compromise. e.g. drilling a new vent
| to the surface is theoretically possible, but very hard in a
| densely populated and built-up area.
|
| A lot of comments talk about tunnel size, which is a minor
| factor: Everything's easier to engineer when you have more
| space. But fundamentally the issue is where to send the waste
| heat, not "tunnel too small".
|
| 1) https://en.wikipedia.org/wiki/Laws_of_thermodynamics
|
| 2) https://en.wikipedia.org/wiki/London_Underground_cooling
| dwroberts wrote:
| The challenge here is specific to this line - other lines (like
| Circle) already have AC on the trains - mainly because they're
| absolutely huge trains by comparison
| rjmunro wrote:
| London 2 main types of underground line: Subsurface (Circle,
| District, Metropolitan and Hammersmith and City lines), and
| tube. The subsurface lines were constructed by cut and cover
| and were made for steam engines. They are much larger than
| the tube lines. The Tube lines are tunnelled, and designed
| for electric power only.
|
| It's not really the size of the trains that allows AC on the
| subsurface lines, it the fact that the lines are well
| ventilated to allow steam and smoke from steam engines to
| escape.
| dwroberts wrote:
| Even the article specifically points out the size of the
| train as an issue
|
| > To fit air conditioning into the trains has been rather
| an interesting challenge, as air conditioning units are
| large and tube trains are small, and Siemens Mobility has
| taken several ideas and put them together to create the
| space needed.
| Cthulhu_ wrote:
| It is here; they're small trains and the tunnels are very warm
| already, so the AC isn't as efficient, and adding more heat to
| the tunnels (which all comes from the running trains) will make
| it more inhospitable.
|
| There are some projects underway to try and cool the tunnels,
| but they're deep underground and have accumulated heat over
| decades.
| DoughnutHole wrote:
| Air conditioning in a busy 19th century underground tunnel
| system is absolutely an achievement.
|
| Air conditioning an underground train means pumping that hot
| air into the tunnels. The tunnels have insufficient ventilation
| because this wasn't conceived of as a problem when many of them
| were built, and that's a challenge to rectify.
|
| There's also the issue that the trains are already making the
| tunnels too hot. 4000 trains running back and forth generates a
| lot of heat from both the engines and braking friction. That
| heat goes into the clay of the tunnel and is very slow to
| dissipate due to the high heat capacity of the clay. The trains
| are never stopped for long enough for the temperature to drop,
| and so the temperature of the clay has slowly risen 5-12
| degrees depending on the line from when the first line was dug
| in 1863.
|
| Air conditioning the carriages of the new trains didn't result
| from any developments in air conditioning technology, but from
| breakthroughs reducing the thermal output of the engines and
| brakes. This gives them a heat "budget" letting them air
| condition the carriages without outputting any more heat into
| the tunnels than a standard train.
| Roark66 wrote:
| I 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 wrote:
| If 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 wrote:
| I 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 wrote:
| The 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 wrote:
| The 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)
| rob74 wrote:
| According to
| https://en.wikipedia.org/wiki/New_Tube_for_London, "energy
| consumption 20 per cent lower than existing trains due to
| regenerative brakes, LED lighting and lighter construction"
|
| ...and apparently they managed the "lighter construction"
| mostly by reducing the number of bogies? According to
| https://en.wikipedia.org/wiki/London_Underground_1973_Stock,
| current Piccadilly line trains have two 3-car units, which
| means 2x3x2 = 12 bogies. If you look at the video, the new
| train seems to be just one unit with 5 "actual" cars (with
| bogies) and 4 bogie-less segments suspended in between, which
| means just 10 bogies. Also, the new trains are 7 meters
| longer than the old ones.
| codelikeawolf wrote:
| As an American that has been to Europe several times, I would
| say "not emitting heat" is an accurate description of AC in
| western Europe in general. I'll never forget driving with a
| friend in Germany when it was about 85 degrees outside and
| they set the AC to 78 with low fan speed. I'm not trying to
| throw shade, I just wish I could be happy with that amount of
| cooling. I would have turned it down to 68 and blasted the
| fans (when I'm sweating, I want my AC to feel like I just
| entered a walk-in fridge loaded with box fans). I suppose it
| explains why Americans have such a huge energy footprint.
| SoftTalker wrote:
| I'm an American, and I typically don't use the AC in a car
| unless it's above about 90 degrees, I just open the
| windows.
| rtkwe wrote:
| Is there a reason why? If it's fuel efficiency the AC is
| far more efficient than the drag open windows adds. Fresh
| (ish given you're on a road) air I kind of get but at
| anything other than city speeds the noise gets unpleasant
| fast for me.
| SoftTalker wrote:
| Yeah I just prefer fresh air (even knowing that newer
| cars with in-cabin air filters probably have cleaner air
| than outside). If I'm sitting in city traffic and not
| moving much, I do use the AC more.
| codelikeawolf wrote:
| That's fair. I grew up in the midwest where it gets
| pretty humid in the summers. Even when it's in the 70's,
| driving with your window open doesn't help with feeling
| gross and sticky.
| Symbiote wrote:
| If I travel from Northern Europe to hot places, the first
| thing I have to do in the hotel room is turn the
| temperature up about 5-10degC.
|
| If it's 30degC outside, 25degC is a reasonable room
| temperature. I don't want a shocking transition when I go
| in and out.
|
| Last year I visited a place with almost 40degC outdoor
| temperatures, and I set the car AC to 28-30degC.
| onetimeuse92304 wrote:
| But wouldn't this make the problem even worse? Air conditioning
| will dump even more heat into the tunnels.
| Symbiote wrote:
| See the 10th paragraph of the article.
| ocharles wrote:
| For 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 wrote:
| Oh, 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 wrote:
| It'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 wrote:
| No, 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.
| cjrp wrote:
| Given that the trains stop at the platforms within quite a
| small area, I wonder if they could store that heat between
| stations and then dump it into a sort of extractor which takes
| it to the surface (or uses it to heat buildings, etc.)
| onetimeuse92304 wrote:
| That would be very complex and expensive.
|
| Technically, you could just pump out hot water and pump in
| some cold water, on every station.
|
| But achieving reliable coupling between the train and any
| kind of piping system would be complex. Remember, there is
| electricity involved already and you don't want to mix
| leaking pipes and electricity.
|
| When you realise you have to do something very reliably on
| every train stop, on every car a more passive solution like
| piping cold water through the rock might be cheaper long
| term.
| hlandau wrote:
| I was just thinking about something like this.
|
| I'm not sure you'd actually need to have physical coupling
| from the train to the platform. Train lavatories used to
| just dump their contents out of the track. Given that tube
| trains are already required to stop at a very precise
| location on the platform, perhaps the hot water could just
| be dumped into a funnel built into the ground underneath
| the track beneath the rails.
|
| Getting cold water onto the train would be harder. Perhaps
| a big funnel on the top of the train underneath a pipe? ;)
| the_mitsuhiko wrote:
| I found it very funny to see these trains parked behind my house.
| I live in Vienna, but apparently some were assembled here.
| bluGill wrote:
| Scale 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 wrote:
| US 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 wrote:
| the 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 wrote:
| I 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 wrote:
| They do use the excess heat for some public buildings in
| Islington https://www.islington.media/news/bunhill-2-launch-pr
| SideburnsOfDoom wrote:
| The ground around the deep tunnels already is a heat reservoir,
| over decades it heated up.
| https://en.wikipedia.org/wiki/London_Underground_cooling
| t43562 wrote:
| That 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 wrote:
| The 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.
| ProfessorLayton wrote:
| They don't have to vent air though, for the same reasons
| we don't need to vent air for geothermal heat pumps. It
| doesn't seem all that crazy to drill minimally for some
| coolant lines and run a mini-split style heat pump system
| into the hottest stations.
|
| I'm not saying this is easy per se, but far from
| impossible, or impossibly expensive.
| gsnedders wrote:
| This has been done to some degree at Green Park station,
| which still very much is quite warm in places, for ~PS9M
| about a decade ago.
|
| But when TfL has had its budget slashed, and such
| projects are competing for financing with other projects
| with more direct operational benefit... it's hard to
| justify. And it's still not necessarily easy to drill at
| all!
| ProfessorLayton wrote:
| Agreed that drilling isn't easy, but this does seem more
| like a budgetary and political issue than an engineering
| challenge.
|
| Not much (if any) drilling may even be necessary, as
| there's also the option of running coolant lines directly
| into the train tunnels. Existing water infrastructure
| could also be used as coolant -- especially if it's
| otherwise sitting idle for a fire that hopefully never
| happens!
| Cthulhu_ wrote:
| It would need to be made so that it uses more heat than needs
| to be disposed of throughout the year though. Plus, digging
| heat pumps like that is a huge and complicated undertaking,
| with all the existing underground infrastructure.
| baz00 wrote:
| The Piccadilly line is known as The Tandoor in some parts of
| London, hopefully no more!
| oblio wrote:
| Not 100% sure I get it, I assume because it gets very hot and I
| guess, has a strong odor?
| AlecSchueler wrote:
| It's like an oven, there's not much more to it than that.
| baz00 wrote:
| It'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 wrote:
| I lived in Hounslow for thirty years and got the Piccadilly
| Line daily. I never once heard it referred to as The
| Tandoor.
| baz00 wrote:
| Lived there for 20 years and heard it regularly. Did you
| have headphones on for 30 years on it? :)
| r0bbbo wrote:
| No. And a quick search finds possibly one mention of it
| from 9 years ago on Reddit. It's not widely used.
| robga wrote:
| Living in zone 6 where the underground is overground,
| it's more like Jalfrezi at this time of year.
| danpalmer wrote:
| It's got nothing on the Central Heating Line.
| disruptiveink wrote:
| The 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 wrote:
| This 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
| PS1.6bn 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 PS1.5bn 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 wrote:
| I 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.
| Symbiote wrote:
| How can they make the trains bigger when they're already as
| big as can fit in the tunnels?
|
| (You can read the article to see the reason for the
| windows.)
| blackhaz wrote:
| It's a design issue, not a tunnel size issue. Look at all
| these interior details, not to mention a completely
| identical exterior. It's the rolling stock from the
| freaking past. Obviously there were so many cost-cutting
| measures (or somebody just pocketed all the money) that
| they took the original design, which was pretty cool half
| a decade ago, and just slapped an air conditioner on top
| of it. That's it, dude. That's everything we've got. What
| should have been done is a complete redesign of the car,
| and then they'd be able to figure out how to put all the
| A/C ducts without having to do all this windows crap.
| Hell, it's 2023. The age of rockets landing backwards. We
| should be having panoramic windows in these carts by now.
| seabass-labrax wrote:
| What do you expect to see out of these panoramic windows?
| The Piccadilly line is hardly the most scenic route in
| the UK; there's nothing to see but tunnel walls for more
| than half of the full line. I'm not arguing against
| panoramic windows if they're easily installed, but that
| seems to me like it should be a substantially lower
| priority than air conditioning on the deeper Underground
| lines.
| Symbiote wrote:
| Can you link to the Munich or Amsterdam metro trains? I
| just see fairly ordinary metro trains for a system with
| normal-size tunnels. The design is irrelevant to the
| small tunnels of the Piccadilly Line.
|
| https://en.wikipedia.org/wiki/MVG_Class_C
|
| https://commons.wikimedia.org/wiki/Category:M7_(Metro_Ams
| ter...
|
| A better comparison is with the Circle/District/etc
| lines. Those trains are of similar size to the Dutch and
| German ones, although I think they are designed to carry
| a lot more people so there are fewer seats:
|
| https://en.wikipedia.org/wiki/London_Underground_S7_and_S
| 8_S...
| disruptiveink wrote:
| Correct - that's the stated 10% capacity increase of the new
| trains. It's not nothing.
|
| My disappointment comes from the fact that there are stations
| where the Piccadilly just blazes through and doesn't stop.
| The platforms are there, maintained and in use, but the train
| just goes past. Those areas have been repeatedly told for the
| past decade "no new stops until signalling upgrades which
| you'll get when the new trains come - otherwise it would make
| the journeys longer and we can't have that on a line that
| services Heathrow!".
|
| Now the time has come and the signalling upgrades were axed,
| meaning according to the original logic, no chance of getting
| the trains to stop at your station. Of course new stations
| could be serviced, at a cost of making the journeys slower -
| surely the argument of "if the train stops at your station,
| it'll slow down the journey for everyone" applies to all
| stations, not just a select few? But even if we go with the
| nonsensical "we can't slow down the average journey time",
| other options could be taken, such as making the trains stop
| at the least used stations alternately - you don't even need
| to go full "Express Train" route NYC does if your issue is
| just a couple of stations.
|
| Still, TfL hasn't really shown any interest in touching any
| that and always said "you'll get your stop with the new
| trains". Well, the new trains are almost here and it doesn't
| look like it'll come with a solution, just more of the status
| quo.
|
| Air conditioning is of course great and I'm not advocating
| for maintaining old stock forever. But a shiny new train does
| nothing if the train won't stop at your station. And you're
| not going to get much gains if your shiny new trains are
| effectively throttled to last century speeds with last
| century reliability.
| martinald wrote:
| The capacity increase is 10% in terms of trains per hour
| and another ~10% in terms of how many people you can fit in
| the train, so it's nearly 25% pax carrying increase. Given
| tube numbers are down 20%, since covid, this is a huge
| improvement in space per passenger.
|
| I think you are really overegging the impact of the skipped
| station (turnham green?) You can just get a district line
| train and change. Ok, it's not ideal but it's probably only
| adding 5-10mins to journey times. It's one station on a
| network of hundreds and does not justify billion+ spent for
| it.
|
| And I don't think there is a business case for further
| capacity, as not only would it require resignalling it
| requires another batch of trains to be built to get it up
| to 36tph. There isn't the demand for that post covid. This
| may change but there are much more pressing captial
| projects for tfl (bakerloo line extension for example) imo.
| TechnicalVault wrote:
| The funny thing is the increased capacity wasn't
| necessarily the biggest driver for this upgrade. Part of
| the selling point to Boris Johnson who was mayor at the
| time was that he could stick it to the train driver's
| unions (who were having a big fight with him at the time)
| by introducing automatic train operation.
|
| The problem with relying on post COVID passenger
| reductions is that whilst tube numbers are down 20% since
| COVID that just means they're at the level they were in
| 2009/10. Even if they don't bounce back fully this year,
| post COVID working hasn't cut out the peaky nature of
| tube travel. Even if people work from home Monday and
| Friday, they'll often all come into the office on Tues-
| Thurs making peaks on those days.
|
| I agree the demand for capacity on other lines that is
| even more pressing. Last time I rode the tube regularly
| was 10 years ago and even then I recall the Victoria line
| during rush hour was literally cattle class, your face in
| someone else's armpit. The 2019 numbers put the Northern
| Central, Jubilee and Victoria lines are well over the
| 100% mark at peak time. Despite having the highest
| comparative fares compared to other cities the Tube is
| still woefully underfunded. There is so much technical
| debt because much of the system was built in the 1800's
| and early 20th century. First mover disadvantage, because
| we got to make all the mistakes.
| seanhunter wrote:
| Turnham Green tube for example has platforms for the
| Piccadilly line and it actually stops after 10pm (or if
| there's a problem), but not at other times.
| Tsiklon wrote:
| I've always suspected this is to accommodate for the last
| District line train to Richmond. However I've never
| checked the timetable to confirm when that is. This
| potentially allows users to reach this destination if
| they miss the last train at Hammersmith.
|
| Similar to how the last westbound central line train to
| Ealing Broadway holds at White City to allow the final
| westbound train of the night (towards West Ruislip) to
| transfer the last stragglers from the city
| owisd wrote:
| They just stop late (and early) for the more mundane
| reason of 'because they can', the service is less
| frequent at off-peak times so there's enough time to stop
| at Turnham Green before the train behind catches up.
| jessriedel wrote:
| > surely the argument of "if the train stops at your
| station, it'll slow down the journey for everyone" applies
| to all stations, not just a select few?
|
| No it doesn't. Some stations serve more passengers and
| transfers than others. And even if stations were identical,
| the opportunity cost of stopping goes up as the train gets
| more full.
|
| > such as making the trains stop at the least used stations
| alternately
|
| Yes, this can make sense. But it _doesn't necessarily have
| to_. You have to actually check the numbers.
| SoftTalker wrote:
| IDK if they still do it but Chicago used to run "A" and "B"
| trains that would only stop every other stop. At some
| stations, all trains would stop so you could get off and
| transfer to the alternate train if you needed to.
|
| So basically any given train was only stopping at maybe 60%
| of the stations.
| brnt wrote:
| I knew some buildings that had elevators that worked that
| way: one for even floors, one for uneven ones. I always
| wondered if this really paid off. I guess in a building
| you almost always are either going to or coming from the
| ground floor, and you never need to switch elevator. But
| on a train line you might want to get off at any stop so
| ~50% of people will need to switch.
| ExoticPearTree wrote:
| > It's also not a low cost thing, the SSLs resignalling cost
| at least PS1.6bn and has been horrendously delayed.
|
| Pardon my ignorance, but how can a signaling system cost that
| much money? Is it made out of gold and platinum or what?
| l33t7332273 wrote:
| I'm routinely surprised by how much things like this cost.
|
| I think the answer is that solving this problem takes a
| teak of some size and skill, and paying them while making a
| hefty profit is expensive.
| konschubert wrote:
| It's compliance and bureaucracy that keeps competition
| out.
| arcticbull wrote:
| I think it has more to do with lack of state capacity.
| The agencies responsible for building this don't have
| anyone in-house anymore who can actually plan and carry
| out the job, instead relying on cascading layers of
| consultants and sub-consultants who manage contractors
| and sub-contractors.
| NamTaf wrote:
| That's the price of making complex, real-world hardware
| systems fail-safe. By fail-safe, I don't mean 'never fail'
| but, more literally, fail in a way that remains safe for
| all other systems interfacing with the failing one.
|
| Proving that it fails safely requires a mountain of effort
| and documentation, but it's required because failure
| doesn't just lead to some speculative CPU bugs leaking a
| password or to a browser crash, it leads to _many people
| dying_.
| rglullis wrote:
| To add to your point, the accident in Greece this summer
| that killed 50+ kids was attributed to human error that
| could've been avoided if they had upgraded their
| signalling system like it was promised decades ago.
| ExoticPearTree wrote:
| I get that, but still, it is not like we don't have
| experience with making fail-safe things that we can draw
| from. And once you get a station + track fitted with the
| new system you just copy/paste; so I can understand a
| higher cost in the beginning for the proof of concept,
| but after that everything should be very cheap.
| arethuza wrote:
| "you just copy/paste"
|
| Aren't we talking about physical signalling kit - no
| copying and pasting? 272 stations and ~400km of track - a
| lot of which is pretty difficult to access?
| IshKebab wrote:
| He obviously meant copy and pasting the design. What did
| you think he meant?
| martinald wrote:
| The main three things are:
|
| 1) very complicated and drawn out design/approval processes
| with many expensive consultants involved. on network rail
| you would not believe the amount of studies they have to
| do, including testing the light levels everywhere in a
| carpark to make sure there are no dark spots, amongst a
| billion other small things. there has been endless
| regulation forced on the railways/tfl, which on one hand is
| good for safety but on the other has meant even a tiny
| project needs a trillion risk assessments done, which
| typically get outsourced to specialist consultants, who
| have a massive incentive to find problems so they can
| retest.
|
| 2) lack of competition at the top level contractor layer.
| the procurement rules require really only huge companies
| can bid, which means they can act in a semi-cartel way.
| this is probably difficult to solve given signalling stuff
| but in more basic construction projects it feels like not
| much competition is going on (not suggesting there is a
| cartel here, fwiw, just feels a bit like it!)
|
| 3) on the tube the access is extremely restrictive. you
| tend not to close the line for extended periods of time
| (though this is changing recently as i think people are
| realising the cost of keeping the line isn't worth it vs
| doing a week closure), which means that you have to get all
| your equipment down to the tunnel (which might taken an
| hour), do 2-3 hours of work, then remove all the equipment,
| in 4-5 hour blocks each night between midnight and 5amish,
| which means you are paying people often "night working"
| wages for working really 2 hour shifts, instead of paying
| them normal wages for working through the day for 8 hour
| shifts. This probably increases the cost of labour by
| 5-10x.
| dangus wrote:
| That's less than PS10 per rider of the line. Piccadilly
| line ridership is over 200 million trips per year.
|
| This is a line that has 53 stations. For comparison that's
| 20 more stations than the longest and highest volume L line
| in Chicago.
|
| I wonder how this cost benefit compares to the $9 billion
| project to widen Houston highways?
| yardstick wrote:
| What does PS10 per rider of the line mean? How does that
| help us look at things?
|
| I used to commute 5 times a week (often more) on
| Piccadilly. So that's PS5,200 for my ridership for the
| year? From that perspective seems rather expensive...
|
| It's disappointing they ditched the signal upgrades. It
| will bite everyone soon enough. Some of these systems
| date back over a hundred years, and are all incredibly
| bespoke.
|
| Re the missed stations, I feel like they missed an
| opportunity with the Elizabeth Line line to shift more
| Heathrow traffic that way, giving some breather to
| Piccadilly during signal upgrades.
| dangus wrote:
| The average American spends $5,000 a year on the total
| cost car ownership, completely separate from public
| spending on roads and infrastructure, so I think that
| signaling cost is reasonable enough, especially since
| signaling will last far longer than the typical lifespan
| of a personal vehicle.
|
| PS5200 for your annual ridership but then divide that by
| the lifespan of the signaling. Let's say it lasts 30
| years, so that's EUR173, (but of course, at the end of
| the 30 years PS173 is worth a lot less).
| yardstick wrote:
| So probably better to pitch it not as PS10 per rider
| (~200m annual riders) but PS0.33/trip levy for the next
| 30 years.
| robertlagrant wrote:
| How much an American spends on a car every year seems not
| that relevant to how much a British tube line signal
| upgrade costs. Why not compare it to house prices in
| London, and it'll seem even cheaper?
| nsteel wrote:
| What do you mean by missed opportunity? To not run it
| there more frequently? Can't they still do that? The
| timetable has seen some updates already.
| mcfedr wrote:
| Corruption
| dallyo wrote:
| > I also believe the new trains can accelerate faster so new
| stops are potentially possible.
|
| Is accelerating faster a practical solution though,
| considering how many people are standing?
| nickt wrote:
| I had to look it up:
|
| SSL = sub-surface line
| ploxiln wrote:
| In NYC, faster-accelerating subway trains, with not-better
| brakes, actually caused slower subway service. The coarse-
| grained signaling had to assume the worst case: a subway
| train that started max acceleration (operator fainted on gas
| pedal?) just after a signal, and wouldn't have emergency
| brakes automatically tripped until the next signal. So faster
| accelerating cars can get faster in that segment, and require
| keeping more signal-blocks of spacing between trains for max
| emergency braking distance. (So, really the fault of old
| signals and brakes, but still, faster trains had slower
| service :)
| https://homesignalblog.wordpress.com/2022/12/21/how-we-
| slowe...
| mnd999 wrote:
| It's bonkers. It stopes at South Ealing which is about 10
| yards from Northfields but not at Turnham Green which is
| super busy.
| DoreenMichele wrote:
| Glad to see this top comment. I saw the headline and thought it
| would be more handwringing about climate change, a la "Look!
| Even northern Europe needs AC these days."
| JCM9 wrote:
| Cooling 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 wrote:
| ...especially with such cramped stations and tunnels as the
| London tube!
| the_other wrote:
| The 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 wrote:
| If 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_ wrote:
| As is oxygen and waste; I never thought of it as an analog
| to the same problems that the tube has.
| droopyEyelids wrote:
| same problems as life on planet Earth!
| rtkwe wrote:
| With the convenience of thermodynamically impossible heat
| deletion mechanics though. Steam turbines in that game
| delete heat for every bit of energy they produce.
| alex_duf wrote:
| I'm hoping the aircon filters will start clearing the
| filthiness of the tube air. Something tells me they'll have to
| change them more often then think.
|
| Once you see it, you can't unsee it. There's this dark mist in
| the London underground, I find it very visible on the northern
| line, around elephant and castle. Just standing at one extreme
| of a platform and trying to look at the farthest part of the
| station, you'll realise everything is "foggy" by lack of a
| better term.
|
| One hour there would turn my snot black.
| morkalork wrote:
| There was a study on the TTC subway and they discovered the
| air quality was 10x worse than above ground and on par with
| Beijing. The accumulation of dusty linty particles on the
| walls has a cute name too "tunnel fur". I remember seeing
| workers going into the tunnels wearing N99 masks after that
| report was released.
| glompers wrote:
| I always like the (grease?) smell in Montreal Metro
| stations but never thought about it in terms of particulate
| matter concentrations.
| morkalork wrote:
| Unfortunately the only smell I can associate with the
| Montreal metro is piss
| VK538FY wrote:
| I understood that the Montreal metro trains used wood
| breaks and peanut oil. Hard to say if that makes the same
| mess, but the rubber tires surely leave something. Also,
| the new rames may use different breaking technology.
| rjmunro wrote:
| One thing the article doesn't mention is that the trains are
| more efficient because they use regenerative braking, rather
| than friction brakes. The friction brakes cause a lot of the
| heat and dust in the underground.
|
| By eliminating this heat, they are able to use that heat
| budget to run air conditioners on the trains and they still
| make less heat overall. As a side effect, the dust should be
| reduced too (and probably a bit of the maintenance)
| rob74 wrote:
| There is actually an intermediate step between "friction
| brakes" and "regenerative braking" - electric trains can
| use the engines to brake, but the current produced is then
| fed to resistors, which dissipate it as heat, rather than
| used to charge a battery or to feed it back into the power
| supply line - https://en.wikipedia.org/wiki/Dynamic_braking
| #Rheostatic_bra.... So the friction brakes are actually
| only used when maximum braking is required - and these will
| also be needed with regenerative braking. Using
| regenerative instead of rheostatic braking will however
| lower the amount of heat produced I guess...
| cpncrunch wrote:
| The 1973 trains already used rheostatic braking. The new
| ones use regenerative braking.
|
| https://www.modernrailways.com/article/revolution-
| piccadilly....
|
| http://www.trainweb.org/tubeprune/73%20tube%20stock.htm
| Cthulhu_ wrote:
| I can understand that cooling a tunnel network like that is
| difficult, but surely filtering particles from the air is a
| solvable problem? Movable air filters on the platforms, etc.
| kilotaras wrote:
| Step 1 is to measure and declare a problem. To the best of
| my knowledge there's no systematic measuring of air
| pollution on the stations.
|
| Same with loudness which on some (old) lines is way past
| safe.
| Symbiote wrote:
| Air quality is measured:
| https://tfl.gov.uk/corporate/about-tfl/improving-air-
| quality...
| kilotaras wrote:
| I can get real time air quality index above ground on
| multitude of places.
|
| The most up-to date information on the tube I could found
| was this report[0], that only covered a number of
| stations. Even then, the information provided is not
| great, e.g. for Highbury & Islington:
|
| > The results for particulate matter were between <0.02
| and 2.16 mg/m3 for PM2.5.
|
| Results cover the range from 4x of WHO recommended limit
| (5 mg/m3, i.e. 0.005 mg/m3) to 432x.
|
| [0] https://content.tfl.gov.uk/dust-monitoring-lu-
| stations.pdf
| JAlexoid wrote:
| Tunnels - sure, that's a challenge.
|
| But stations - that's a cost. Stations are connected to the
| surface by multiple shafts, or are already exposed.
| odiroot wrote:
| New Elizabeth Line's trains are quite pleasant though. Not sure
| if the stations have any better ventilation than e.g. Northern
| Line.
| ivix wrote:
| Cooling the stations is not an engineering challenge. It's a
| budget challenge. Installing and operating huge chillers is a
| solved problem.
| SideburnsOfDoom wrote:
| > Cooling the stations is not an engineering challenge.
| Installing and operating huge chillers is a solved problem.
|
| Not correct in context. You cannot successfully chill air
| without having a place to vent the resulting waste heat.
|
| Where, in deep tube lines, to vent the waste heat, is _not_ a
| solved problem. It _is_ an unsolved engineering challenge.
|
| The heat has been accumulating there for decades.
|
| As detailed here
|
| https://en.wikipedia.org/wiki/London_Underground_cooling
|
| https://news.ycombinator.com/item?id=38364027
|
| https://news.ycombinator.com/item?id=38363476
| jwmoz wrote:
| If anyone from TFL is reading this, for the love of God please do
| the Victoria line next.
| NamTaf wrote:
| I'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 wrote:
| I 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-t...
| nsteel wrote:
| And 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 wrote:
| Carpet never belongs on city trains. How does this keep
| happening?
| Cthulhu_ wrote:
| Where are you seeing carpet? Looks like vinyl or linoleum to
| me. Or do you mean the upholstery?
| fortran77 wrote:
| It's nice to be able to go to Cockfosters in comfort.
| a_c wrote:
| Will it get any quieter, though? And why can't we get rid of the
| moquette, they get disgusting quickly.
| dyerjohn wrote:
| I 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
| lotsofspots wrote:
| I 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 wrote:
| No, 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.
| virtualritz wrote:
| The 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
| kwhitefoot wrote:
| Can'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 wrote:
| If 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 wrote:
| I wonder if they could bore some geothermal loops to move the
| heat someplace else to dissipate more easily.
| eesmith wrote:
| Being done. 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) 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.
| rtkwe wrote:
| They took some heat sources away by switching to regenerative
| braking and moving to LED lights so the AC has some head room
| to play with for not introducing more heat. These trains are
| supposed to run cooler overall than the ones they're replacing
| taken as a whole including the new AC.
| RichardCA wrote:
| Was 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-ou...
| InTheArena wrote:
| A video tour: https://www.youtube.com/watch?v=mlP9cJOHEEc
| m463 wrote:
| Does 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.
___________________________________________________________________
(page generated 2023-11-21 23:03 UTC)