‘The Trains Are Slower Because They Slowed the Trains Down’ • Hacker News Board

Re: ‘The Trains Are Slower Because They Slowed the Trains Down’

#51

Post by njarboe » Tue, Mar 13, 2018, 7:45 PM UTC

alexbeloi wrote: post #25

smilekzs wrote: post #14

Risking asking the obvious: What is stopping us from having autonomous subways, considering we are almost gonna have autonomous cars?

In principal Bart[0] is supposed to be operated almost automatically and the train operator is there for announcements, closing doors and watching the track for hazards. In practice, the operator does a lot of speeding up/down manually. I can't find it now, but I remember reading an article that claimed that Bart trains were operated in manual mode 90% of the time, not sure the reason. [0] https://en.wikipedia.org/wi…

Probably because otherwise the operator gets really bored and feels the machine is driving him instead of the other way around.

Re: ‘The Trains Are Slower Because They Slowed the Trains Down’

#52

Post by gsnedders » Tue, Mar 13, 2018, 7:46 PM UTC

bluGill wrote: post #39

smilekzs wrote: post #14

Risking asking the obvious: What is stopping us from having autonomous subways, considering we are almost gonna have autonomous cars?

Money. The technology is not hard to create, but it does take a bunch of engineers time and effort to design it all (probably a mix of mechanical and computer work), and then more time to buy the equipment and install it. There is nothing off the shelf, even if some other subway gave them all the design (unlikely), it would still be hundreds of thousands of dollars per train to make it fit the New York trains.

> There is nothing off the shelf, even if some other subway gave them all the design (unlikely), it would still be hundreds of thousands of dollars per train to make it fit the New York trains.

What? Alstom, Ansaldo STS, Bombardier, Siemens, and Thales all have off-the-shelf designs that they will happily sell. And I've probably forgotten some here. I realise none of these are American companies, and "Buy American" is often a constraint on acquisitions in the US, but it's fundamentally untrue that there are no off-the-shelf designs.

See, e.g., https://en.wikipedia.org/wiki/Communications-based_train_con... for various systems using various suppliers' products.

Re: ‘The Trains Are Slower Because They Slowed the Trains Down’

#53

Post by the8472 » Tue, Mar 13, 2018, 7:46 PM UTC

Single shot timers? Exclusion locks on fixed sections of the track?

Modern control systems such as ETCS3 can allocate virtual track segments (moving blocks) to individual trains and adjust the reserved length based on the current speed.

Re: ‘The Trains Are Slower Because They Slowed the Trains Down’

#54

Post by kelvin0 » Tue, Mar 13, 2018, 7:49 PM UTC

smilekzs wrote: post #14

Risking asking the obvious: What is stopping us from having autonomous subways, considering we are almost gonna have autonomous cars?

Never underestimate the power of unions. They can make or break a technology. Automated driver less subway cars create a precedent which can make unions feel threatened.

Of course the reality of it is more complicated, but they are a powerful force (for better or worse).

Re: ‘The Trains Are Slower Because They Slowed the Trains Down’

#55

Post by masklinn » Tue, Mar 13, 2018, 7:51 PM UTC

sbarre wrote: post #21

Totoradio wrote: post #18

Earlier quoted context omitted.

It's already a thing, first example that comes to mind is line 14 in the Paris metro: https://en.wikipedia.org/wiki/Paris_M%C3%A9tro_Line_14

The Skytrain in Vancouver does not have human conductors either. Although I would assume there are conductors in a control centre somewhere?

There are no conductors, there's a control room with system overview and links to metros, stations and service personnel.

See http://www.ansaldo-sts.com/sites/ansaldosts/files/brochures/... page 21.

Re: ‘The Trains Are Slower Because They Slowed the Trains Down’

#56

Post by stuaxo » Tue, Mar 13, 2018, 7:51 PM UTC

guardiangod wrote: post #12

arzt wrote: post #4

Earlier quoted context omitted.

More importantly, they used the overcrowding excuse as a means to raise $800mm+ from New York taxpayers. If this capital wasn't necessary given the problems they cited were non-existent, this amounts to fraud.

That's not a really fair way to put it as the signaling system is still the root cause of the slowdown. 1. Outdated signaling system cannot handle current load at high safety threshold 2. Network could not upgrade signaling system due to lack of money 3. Network responses by slowing down critical paths and putting in more locks 4. System capacity drops So yeah, you still need the money to fix slow things.

Yup - need to pay to get the signals sorted. I guess the you might unearth a bunch of other things, that need sorted... but it just needs doing.

Re: ‘The Trains Are Slower Because They Slowed the Trains Down’

#57

Post by gsnedders » Tue, Mar 13, 2018, 7:52 PM UTC

njarboe wrote: post #44

This article has a lot of text before getting to describing the problem. Summary: Train wreck 1995 and a installation of a safety-first, CYA response that slows down the trains and does not increase safety. Longer Summary: Train wreck in 1995. Maybe driver was asleep. Start installing new signals that not only automatically stop the trains when there is a train ahead (good idea and already in place), but also when go…

> Drivers go even slower than 45mph because the train is automatically stopped when going faster (as you would want to do if there was a train ahead) instead of just giving a warning and letting the train keep going.

Is there any protection system that allows the maximum speed to be exceeded with just a warning? Certainly all those I can think of (TPWS, TVM, PZB, or something more modern like ETCS) have a given maximum speed you're allowed to exceed by a small tolerance but nothing more (though, of course, the system may be isolated, but that's not allowed in passenger service).

The failing here sounds like it is setting the line speed to 45mph rather than anything higher.

Re: ‘The Trains Are Slower Because They Slowed the Trains Down’

#58

Post by soperj » Tue, Mar 13, 2018, 7:53 PM UTC

iooi wrote: post #50

smilekzs wrote: post #14

Risking asking the obvious: What is stopping us from having autonomous subways, considering we are almost gonna have autonomous cars?

I've said it before [1] and I'll say it again, even if I get downvoted to hell again: Unions NYC has some of the strongest unions in the country. Everything from hotels to the MTA are plagued by really, really strong unions that only care about their interests -- leaving the city with a shameful transit system, in this case. Unions make up nearly 25% of workers in NYC[2], that's more than the double the national aver…

So really the answer isn't unions. It's corruption. Unions work in many places in the world.

Re: ‘The Trains Are Slower Because They Slowed the Trains Down’

#59

Post by gsnedders » Tue, Mar 13, 2018, 7:55 PM UTC

the_mitsuhiko wrote: post #40

jstalin wrote: post #20

Earlier quoted context omitted.

Unions.

There are countries with way stronger unions and automated trains. I doubt unions are the deciding factor.

Union culture can be significant though. From my understanding, in the US I'd expect a union to refuse any form of automation indefinitely; in other countries, they might accept it if the redundant staff are provided training for another job with good employment prospects.

Re: ‘The Trains Are Slower Because They Slowed the Trains Down’

#60

Post by slippers » Tue, Mar 13, 2018, 7:56 PM UTC

could it be that more time spent inside a train increases profit? maybe they just want passengers looking at advertising. they are a captive audience.