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South Kensington station's escalator replacement project

ianvisits.co.uk

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Re: South Kensington station's escalator replacement project

#91

Post by ddek »

asdff wrote: post #81
ddek wrote: post #39

Earlier quoted context omitted.

Compound that with the depth work too. Unlike most metro systems, many London Underground (tube) lines are bored, and at a much greater depth. The Northern, Victoria, Bakerloo and Jubilee lines go under the river; while most systems route trains over bridges. The history of the tube is fascinating. The most recent lines (Victoria, Jubilee, CrossRail/Elizabeth) were built by a centralised authority. The older lines we…

As dramatic as line closures are, the impact to commuters can be minimized if the transit agency supplies shuttlebusses servicing the line in its place. When LA metro closed substantial sections of the Expo and Blue lines a few years ago, the shuttle routing only added a few extra minutes to commuters trips along those corridors.

Nice idea, but no chance it works in London. It’s faster for me to go the long way round the northern than anything overground, even a taxi.

Re: South Kensington station's escalator replacement project

#92

Post by bartread »

tomfanning wrote: post #64
bartread wrote: post #55

Earlier quoted context omitted.

This happens in software too. Over the last 4 years our team has achieved a lot: huge numbers of valuable changes and improvements to our platform. But it's been much harder than it might otherwise have been because we've had to make those changes with the systems in use. Had we started from scratch, or been able to take downtime, there are a lot of projects we could have done much more quickly, but we had to keep th…

Isn't this completely standard practice now?

Not always. I've worked on all sorts with different companies.

Re: South Kensington station's escalator replacement project

#93

Post by gsnedders »

FabHK wrote: post #31

The article didn't mention the length of the escalator? Longest ones apparently are to be found at the Park Pobedy metro station in Moscow at 126 m, and in St Petersburg. Longest escalator system, and my favourite, is the Hong Kong Central–Mid-Levels escalator, at 790 m (2,600 ft). Many people's commute to work. https://en.wikipedia.org/wiki/Central–Mid-Levels_escalator Escalator accidents: 1982 Moscow https://en.wik…

IIRC, they're not particularly long. The deep level tunnels are something like 20m below the subsurface tunnels, I'd guess 30m in total from the ticket hall?

Re: South Kensington station's escalator replacement project

#94

Post by gsnedders »

traceroute66 wrote: post #46
s15624 wrote: post #13

Earlier quoted context omitted.

The majority of the tube network is pretty much already at peak capacity, with trains on the Victoria, Jubilee and Northern being full autonomous with moving block systems as separation distance can now only be maintained through autonomous systems. I think an express service would be wonderful but it would require careful orchestration. I think it might be worth increasing the line speed through signaling upgrades a…

Isn't the problem with automation on the tube less the technology but more the unions ?

Full automation—without drivers—would typically require platform edge doors, which are expensive and troublesome to introduce without disrupting service, and very difficult on some of the curved platforms.

The benefit for the cost involved really just isn't there; while drivers aren't cheap they aren't impossibly expensive in comparison with the average number of passengers per train.

Re: South Kensington station's escalator replacement project

#95

Post by ljm »

barneybooroo wrote: post #8

It is amazing how what might seem like fairly routine engineering jobs become completely nightmarish once you do it underground. I used to commute via Goodge Street every day. A few years ago they replaced the four lifts (in twos so that two were still in service) which ultimately took two years. I could never really fathom what it was that specifically slowed that down so much but hey the lift congestion every morni…

I like taking the stairs at those stations. I think Russell Square is the station with a particularly long staircase; 200 or more steps.

If you like epic spiral staircases you can't go wrong in London.

Re: South Kensington station's escalator replacement project

#96

Post by pavon »

jon-wood wrote: post #45
adwww wrote: post #40

Earlier quoted context omitted.

Could you have odd / even trains that miss stops?

Not without passing places, because you can't miss a stop without the train in front of you also missing it, at least without an eye watering body count.

Depends on how closely you are trying to run those trains! If they are both skipping every other stop, they will both have the same mean speed, and thus shouldn't have to pass one another if there is sufficient initial spacing.

For example, in the simple case where the stations are evenly spaced, if train B arrives at station 1 at the same time that train A arrives at station 2, then they will leave at the same time and arrive at stations 3 and 4 respectively at the same time, and never catch up with each other.

Re: South Kensington station's escalator replacement project

#97

Post by ljm »

ddek wrote: post #39
barneybooroo wrote: post #8

It is amazing how what might seem like fairly routine engineering jobs become completely nightmarish once you do it underground. I used to commute via Goodge Street every day. A few years ago they replaced the four lifts (in twos so that two were still in service) which ultimately took two years. I could never really fathom what it was that specifically slowed that down so much but hey the lift congestion every morni…

Compound that with the depth work too. Unlike most metro systems, many London Underground (tube) lines are bored, and at a much greater depth. The Northern, Victoria, Bakerloo and Jubilee lines go under the river; while most systems route trains over bridges. The history of the tube is fascinating. The most recent lines (Victoria, Jubilee, CrossRail/Elizabeth) were built by a centralised authority. The older lines we…

It's like Passeig de Gracia in Barcelona, going from the green line down to the more central yellow and purple lines.

It's sometimes quicker, or at least nicer, to walk above ground than it is to take the gigantic tunnel (spanning maybe 3 blocks) between the two.

Re: South Kensington station's escalator replacement project

#98

Post by gsnedders »

asdff wrote: post #81
ddek wrote: post #39

Earlier quoted context omitted.

Compound that with the depth work too. Unlike most metro systems, many London Underground (tube) lines are bored, and at a much greater depth. The Northern, Victoria, Bakerloo and Jubilee lines go under the river; while most systems route trains over bridges. The history of the tube is fascinating. The most recent lines (Victoria, Jubilee, CrossRail/Elizabeth) were built by a centralised authority. The older lines we…

As dramatic as line closures are, the impact to commuters can be minimized if the transit agency supplies shuttlebusses servicing the line in its place. When LA metro closed substantial sections of the Expo and Blue lines a few years ago, the shuttle routing only added a few extra minutes to commuters trips along those corridors.

You need 187 buses per hour to have the same capacity as the Piccadilly Line has on-peak (using the capacity of the New Routemaster), or, alternatively, three buses per minute. It's hard to imagine any way in which that is practically workable. I think the most frequent bus service in London currently is scheduled for 30 buses per hour, by way of comparison.

Add to this the fact that average road speed in Central London is about a third of average Underground speed, hence you're quite possibly looking at making journeys three times as long, even ignoring the extra congestion that all those buses would cause.

Re: South Kensington station's escalator replacement project

#99

Post by tialaramex »

tomfanning wrote: post #64
bartread wrote: post #55

Earlier quoted context omitted.

This happens in software too. Over the last 4 years our team has achieved a lot: huge numbers of valuable changes and improvements to our platform. But it's been much harder than it might otherwise have been because we've had to make those changes with the systems in use. Had we started from scratch, or been able to take downtime, there are a lot of projects we could have done much more quickly, but we had to keep th…

Isn't this completely standard practice now?

24/7 is table stakes for many Internet companies, but lots of outfits which think of themselves as delivering that sort of service actually cheerfully carve out hours or even days of down time as "necessary".

One of my banks decided it was going to do a "major upgrade" one weekend. Advertised I think maybe 8 hours outage like hey, who needs a bank for eight hours right? And of course their team can't actually hit that schedule, but nobody wants to choose "Roll back, fall on my sword at breakfast time" so an hour after the end of that supposed 8 hour outage their telephone support were telling me it ought to be fixed "soon" and any problems are only "temporary" and I can try again in a few minutes.

They got it back later that day, no noticeable improvements and you can bet that even if there was some enquiry about what went wrong nobody learned anything from it. Like NASA after Challenger. And they will still send representatives to the IETF who will say well, we can't afford these random outages like you Internet people, we're a bank, we need high availability. And those representatives will look around wondering why everybody is laughing.

Re: South Kensington station's escalator replacement project

#100

Post by tialaramex »

Ichthypresbyter wrote: post #76
nickdothutton wrote: post #28

Earlier quoted context omitted.

One of the things you need to remember when thinking about the London Underground, is that it was a scheme that was ultimately unfinished. There were great plans between the world wars to extend it in size and functionality but ultimately these were all stopped by WW2 and an impoverished UK couldn’t afford to do them afterwards. It was planned to extend the network well into Surrey, Kent and other places.

They also chose not to build many of the suburbs that the extended lines would have served, and instead to keep those areas rural as the Metropolitan Green Belt and to build new towns further away from London.

I grew up in the resulting green belt with restricted residential development of Metroland. Of course in practice what happens is that many people who "must" work in the City but have the salaries that come with that, choose to move, especially when they have young families, out to "the countryside" where the Metropolitan Line ends at e.g. Amersham.

There you can walk from your house (with a view of woodland and fields across the valley) to a London Underground station (you probably don't actually catch an Underground train, even the express takes too long, you catch a "normal" commuter train serving the same station but these days it's the same price because it's the same system) in the morning and the reverse even evening. And your children grow up away from the noisy polluted city, but not so far away that you can't take them to see a stage show or one of the museums on a whim.

Which is nice for them, but hardly screams "sustainable" as a society.

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