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.

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.

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.

> 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.

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.

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

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.

It's such a busy station for being a local station (out of the TfL station types, the least-used), and the District Line beyond this is often quite crowded at rush hour -- it's rare that I get a seat starting from Turnham Green at rush hour.

Having the Piccadilly stopping here during the day would allow for better passenger distribution -- I've often found that one or the other line is brimming with passengers even when the other is half-empty.

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.

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.

I was curious about this too, so I decided to simulate it. It's a fun problem to model and code, with some entertaining places to trip up - for example, that brief awkward period where the elevator is full, but newly arriving people recognize they should not press the button until it leaves. In any case, the answer varies based on the rate of arrival - in some regions of the parameter space it's better if all elevators stop everywhere (intuitively, if odd people arrive every 2 min and it takes 3 min to go up and down, it becomes too expensive to have to wait for the odd elevator). But even in cases where interleaved floors performs better than all floors, there's a solution which is even better there - lower half of the floors on one elevator and the upper half (plus ground floor) on the other. This will make for a fun interactive notebook.

> It's also not a low cost thing, the SSLs resignalling cost at least £1.6bn 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?

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.

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.

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.

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.

"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?

He obviously meant copy and pasting the design. What did you think he meant?

I have no idea - that's why I was asking. I've been responsible for installing systems that had the same "design" into multiple physical locations - hundreds of physical devices at each location.

Having a common design does help but it doesn't help that much as most of the problems are with the physical realities of each location - and what I did was much simpler and less critical than signalling.

Ahhhh! "just" - the magic word!

It is not ever 'just'. This isn't copying code. This isn't building identical silicon for multiple end users. This is more like trying to add additional threads to something that is not embarrassingly parallel. What you're saying is like saying 'why can't you just make all of my computer programs run on all 32 of my CPU cores?'.

And even if you minimise the increasing complexity added by expanding the system, waterfall-style design (which is absolutely the most appropriate approach when dealing with these sorts of projects) front-end loads a frankly Herculean amount of risk management into the process because you want to make sure that's all absolutely square and true before you progress to implementation.

Lastly, it's worth noting that with systems this complex, a lot of the detail is bespoke because the number of complicating input variables the system is exposed to necessarily requires a relatively bespoke solution. Yes, the idea of e.g. ETCS being ETCS is going to hold, but how that works in reality, how it ties in to all of the other legacy systems, etc. will mean that you can't for example just take ETCS-equipped train A and and drop it into ETCS-equipped network B.

I was thinking that only the track sensors and traffic lights along the way need to be upgraded and the drivers would just drive trains as usual and they would be sequenced on a shorter distance/time between trains. I forgot that trains also have to be connected to the new system.

That’s less than £10 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?

What does £10 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 £5,200 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.

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.

£5200 for your annual ridership but then divide that by the lifespan of the signaling. Let’s say it lasts 30 years, so that’s €173, (but of course, at the end of the 30 years £173 is worth a lot less).

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?

I compare it to automobile infrastructure because public transit infrastructure projects sems to be the only time anyone complains about high infrastructure costs.

The only reason I compare it to America is because I don't actually know the figures for the UK, but I expect that car owners would spend more there due to higher cost of petrol, higher vehicle taxes, etc.

Cars are unreasonably useful, though. If you're going anywhere to work / school / moving house / going on holiday / dropping kids at a friend's house, they work for a million uses.

That's why I don't think they compare well: many people who use public transport, even the Tube or similar, still need a car, at least sometimes. So it's not an alternative, and it's not equivalent value.

So probably better to pitch it not as £10 per rider (~200m annual riders) but £0.33/trip levy for the next 30 years.

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.

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.

It’s compliance and bureaucracy that keeps competition out.

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.

Corruption

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.

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.)

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.

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_Amster...

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_S8_S...

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.

That is absolutely not it but sure, go off. The article covers improvements to various systems e.g. braking, wider doors, a fully walk-through carriage (consider how an end wall affects crashworthiness), additional headroom, as well as room for 10% more ridership capacity (bodies have to fit somewhere).

Moreover, there's something to be said about consistency of design when it comes to maintenance familiarity and parts interoperability. Consistent design language also tends to happen when you are catering to disability accessibility requirements and providing clear user interfaces for passengers (including those with disabilities, or those who do not speak English).

Lastly, expecting a complete redesign is committing to an astronomical amount of expense relative to even using just some of the old design DNA. However, I'm not even convinced they've just reused an old design. For starters, a different company did these (Siemens vs Bombardier) and secondly I'd bet that there's a whole lot of difference under the skin that is masked by the natural convergence of design appearance driven by the multitude of requirements set forth by TfL - everything from the design language mentioned above, to their access/egress requirements, fire safety, lighting, etc. etc. There's only so much money governments are willing to throw at figuring out how to skin that cat before it's just not worth it.

> 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?

I had to look it up:

SSL = sub-surface line

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...

It’s bonkers. It stopes at South Ealing which is about 10 yards from Northfields but not at Turnham Green which is super busy.