I havent read the full article, but why is this the number 2 story on HN? Have I sorted incorrectly?
> but why is this the number 2 story on HN?
Because it's interesting to a lot of folks.
South Kensington station's escalator replacement project
11–20 of 110 posts
Re: South Kensington station's escalator replacement project
#12To be honest, for me the most interesting part of the blog post was this one-liner "for an unbuilt high-speed District line service between South Kensington and Mansion House with just one stop at Embankment.". As one of the millions who at some historical point in their lives has had to suffer the District line commute, the above is a thought I used to have regularly whilst stuck sniffing someone's armpit on the Dis…
Express services on shared track isn't common on metro systems. NYC's express subways all use dedicated track, for instance. The tendency to not keep to a strict timetable and the close-running of metro systems makes it hard to slot express trains into gaps between local trains properly.
> The tendency to not keep to a strict timetable and the close-running of metro systems makes it hard to slot express trains into gaps between local trains properly.
To be fair, "close-running" is not a word that tends to be associated with the District line ... "signal failure" is, however ! ;-)
Re: South Kensington station's escalator replacement project
#13To be honest, for me the most interesting part of the blog post was this one-liner "for an unbuilt high-speed District line service between South Kensington and Mansion House with just one stop at Embankment.". As one of the millions who at some historical point in their lives has had to suffer the District line commute, the above is a thought I used to have regularly whilst stuck sniffing someone's armpit on the Dis…
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 and more automation.
Re: South Kensington station's escalator replacement project
#14This is a great example of why underground railways are so expensive to run. I don't believe the London Underground has ever been profitable. Not only is it expensive to install equipment, you then have to maintain it and replace it and in this example, not even "like for like" are going to fit in the same space. When I used to go round various equipment rooms, there was electrical equipment that was the best part of…
That's not right, I'm afraid - the Underground is usually profitable and subsidises loss-making forms of transport (particularly buses). Here's some high-level, pre-pandemic figures: https://diamondgeezer.blogspot.com/2018/03/average-yield-and... (based on TfL's draft budget for 2018-19)
There is so much pent up demand for transport in the UK that it completely distorts things. You can have a system that is overcrowded, profit making, expensive for users, and underfunded all at the same time. The economic pulls that could fix this are outweighed by things like housing costs.
Re: South Kensington station's escalator replacement project
#15To be honest, for me the most interesting part of the blog post was this one-liner "for an unbuilt high-speed District line service between South Kensington and Mansion House with just one stop at Embankment.". As one of the millions who at some historical point in their lives has had to suffer the District line commute, the above is a thought I used to have regularly whilst stuck sniffing someone's armpit on the Dis…
The only way to have express and stopping trains on the same track is to have frequent passing places. Scheduling and signalling get fiendishly complex. On somewhere like the underground, where building those extra passing places is really hard it just isn't worth it.
This is one of the big missunderstandings about the HS2 line. Politicians focus on the shorter journey times, but the big win is actually increased capacity. HS2 will take the express trains off the normal line. With just HS trains on that line you can run more of them than you can if you have stopping trains sharing the track. In addition you should actually be able to run more stopping trains faster since they don't need to be fitted in around the expresses with no extended stops waiting for a delayed express to pass at a station or passing place.
Re: South Kensington station's escalator replacement project
#16I havent read the full article, but why is this the number 2 story on HN? Have I sorted incorrectly?
Because transit infrastructure is really neat.
Re: South Kensington station's escalator replacement project
#17This is a great example of why underground railways are so expensive to run. I don't believe the London Underground has ever been profitable. Not only is it expensive to install equipment, you then have to maintain it and replace it and in this example, not even "like for like" are going to fit in the same space. When I used to go round various equipment rooms, there was electrical equipment that was the best part of…
You have to maintain and replace all infrastructure eventually. Maintenance should be part of the project calculation and how items are maintained should also be part of that. Additionally how things are maintained needs to be updated to go with new technologies and methods.
I see this with for example the public transport in Zürich, Switzerland. Some of the light rail is very old but they are maintenance revisions done on them and things are continuously improved or replaced. Same goes for the tracks which have to be pulled out of the streets every few years and replaced. How this is done has improved tremendously over the years and materials of the track have also changed.
Another example are the electric busses that used to have a gasoline backup generator. These have now all been replaced with batteries as they became small and efficient enough to replace the generator.
Letting the bus run until it's dead will end up costing more than keeping it in good working condition.
Re: South Kensington station's escalator replacement project
#18To be honest, for me the most interesting part of the blog post was this one-liner "for an unbuilt high-speed District line service between South Kensington and Mansion House with just one stop at Embankment.". As one of the millions who at some historical point in their lives has had to suffer the District line commute, the above is a thought I used to have regularly whilst stuck sniffing someone's armpit on the Dis…
Express services on shared track isn't common on metro systems. NYC's express subways all use dedicated track, for instance. The tendency to not keep to a strict timetable and the close-running of metro systems makes it hard to slot express trains into gaps between local trains properly.
Trivia. The timetable, or Working Table, for all London Underground train movements is here https://tfl.gov.uk/corporate/publications-and-reports/workin...
Re: South Kensington station's escalator replacement project
#19Fascinating post as always from Ian. My dad used to work for the underground and hearing him talk about the challenges of the engineering down there was always fascinating. This is especially true for the deep tunnels and the older parts of the network. Trying to keep the whole network dry, when you are dealing with brickwork that might be 100 or more years old, in a water table that has risen a lot following the end…
How did the heavy industry influence the water table ?
I guess they used a lot of water from wells, lowering the water table ?
Re: South Kensington station's escalator replacement project
#20> Down here, there’s no space for heavy machinery, so all the rubble had to be shifted by hand
I wonder, if the engineering train couldn't fit a small loader, something like Avant (perhaps E6 for being electric for confined spaces), though I'm sure there exist some smaller ones too.
Or maybe engineering train could be fitted with a HIAB style thing..