Exploring the Elizabeth line, one of the world’s largest construction projects | Hacker News Reader

Exploring the Elizabeth line, one of the world’s largest construction projects

arstechnica.com

100 pointsantr62 comments

There was an interesting documentary on the BBC a year or so ago following the CrossRail project. One segment in particular was fascinating - a manoeuvre they called "threading the eye of the needle". The Tunnel Boring Machine (TBM) had to go through an gap between an existing underground station at the bottom, and a tunnel for the down escalator at the top ... tolerances were razor thin, much less than 1m either end.

Image that shows what they did here: http://s3files.core77.com/blog/images/2015/01/Crossrail_Plan...

You probably mean this: http://www.crossrail.co.uk/news/crossrail-documentary-the-fi...

Not on iPlayer any more but you can buy it on DVD if your don't think tunnelling is boring. :)

http://www.londonreconnections.com is also a detailed resource.

> "Because the TBMs are so large and unwieldy, two of them—named Phyllis and Ada—were left buried in the ground near the new Farringdon tunnels."

There's a movie plot in that, but I'm not sure if it's a "mad scientist destroys London with TBM" plot, or a "heroic genius saves London from zombies with TBM" plot, or a "Bruce Willis foils terrorists in London with TBM" plot.

I guarantee those machines get referenced in a movie / book in the next decade :-)

I expect they'll be taken over by MI6 and be used to create a high-speed escape tunnel for the staff and agents at Vauxhall Cross

The latest William Gibson book features a sculpture made of diggers recovered from the basements of the super rich erected in a possible future London. Apparently the cost of retrieving them is a major driver in the small digger market!

Diggers being left buried in London seems to be an urban legend. http://www.huffingtonpost.co.uk/2014/06/06/london-urban-lege...

IIRC there's a jail-break plot twist involving them in Oath of Fealty by Niven and Pournelle…

Either that, or someone will open a cocktail bar in them.

I'm surprised no one mentioned the already existing (40 years old!) same project in Paris (called RER). It's full scaled train (even double decker) running underground in Paris and overground outside. The oldest line (A) is the most used line in the world expect Japan (>1 million person/worked day). Auber station was (is?) the biggest underground station in the world and Chatelet-Les Halles is the most used underground station in the world.

No one mentioned it because it is not the same, it is only comparable. RER is, like you said, of the same scale, but 40 years old and proven. You should be happy to bring things you like into the conversation, but not surprised that other people don't like the things you like.

It's a thread about a rail engineering project so I was assuming the crowd was interested by those stuff...

I have to say I'm a bit weirded out by there being a conductor (according to the demo videos) on a brand new subway project. Do the platform door prefigure automation in the future?

Good thing on the large diameter though, IME many of the tube's older sub-surface lines are unfortunately (and uncomfortably for modern average heights) small.

A commenter further down said that these trains are supposed to also run on the normal train lines. This probably means that they have to comply with the regular train regulation, which are quite different from the subway regulations and make automatic driving a lot more difficult.

Yeah. London won't allow fully automated trains without platform edge doors, and it would be impractical to put them on the Great Eastern Main Line or the Great Western Main Line with the variety of other trains that share those tracks. AIUI Crossrail is planned to use fully automated signalling eventually (i.e. similar to the Victoria Line, where the driver only pushes the button at each station and speed is automatically controlled between stations) once ETCS in Britain is standardized enough.

Strange because the DLR is almost completely automated (no driver, but ticket inspector closes the doors) and has no platform edge doors. But they do have emergency stop buttons on the platforms.

AFAIK It's the lack of a human making the close doors / start moving decision that leads to a need for platform doors.

(The Central, Jubilee, Northern and Victoria lines also use automatic operation to similar levels as the DLR, it's just less obvious as the train operator still has a separate cab).

> AFAIK It's the lack of a human making the close doors / start moving decision that leads to need for platform doors.

There is no such need. Lyon's line D has been running fully automatic since 1992 without platform doors[0], the only major accident has been a drunk falling on the train having jumped from a mezzanine.

[0] https://www.youtube.com/watch?v=ubdJ35NBrbE

Same in Copenhagen[0], but they do appear to have LIDAR units monitoring the track edge at stations without doors.

[0] https://youtu.be/R8QvM000uyE?t=151

Copenhagen has since fitted platform edge doors to all stations, above and below ground.

Of course there is no such technical _need_, most kinds of these needs are driven by _legal_ requirements founded in fear of full automation. Fully automated systems were realized before your example already in Vancouver's SkyTrain (1986) and even BART was supposed to be specified to be fully automatic.

Small correction - they can also be driven manually, a flip up panel on the front seat allows the conductor to take control in the case of a complete (or widespread) signalling failure. They're restricted to 12mph though as there are no signals at all and everything must be done by sight.

    > allows the conductor to take control in the case of a
    > complete (or widespread) signalling failure

Or, having ridden that line as part of a regular commute, whenever the conductor gets bored.

I don't think they actually get to drive the train then, just get the press the close door button on the panel. The train still drives to the next station without any human input.

Most automatic trains can't be driven by humans under normal circumstances because signaling information is fed to the train far faster than any human could react to it.

I don't know, but this could have as much to do with TfL politics as technology.

For something like a train I would think you'd want one or more humans babysitting it all the time no matter how automated it is. Thousands of people would ride it every day, all the time, even if it is 100% automated what would be the point in cutting that particular corner? Saving labor costs on conductors are probably not worth it for insurance reasons alone, even if the conductor sits around twiddling his thumbs all day long.

If the conductor sits around twiddling his thumbs all day long, what is the point of him existing in the first place? For a fully automated train system, what useful function does the conductor serve?

As i understand it, there's a rule that requires a member of staff on any train that's properly underground. Ostensibly for safety in emergencies, but possibly because the unions fancied the jobs.

On current tube and big railway trains, that member of staff is the driver. On the DLR, it's the train captain. On an automated Crossrail train, it could be a guard (it's buses that have conductors!).

For more big digs, see also New York City Water Tunnel No. 3, a 60-mile long tunnel that has been under continuous construction since 1970 and which will allow the city's two existing water supply tunnels to be closed for repairs for the first time in a century.

London is also building a water tunnel, but for sewage: https://www.tideway.london/the-tunnel/

It's to be 25km / 16mi long, and mostly run under the river, and should take 9 years in total to build.

https://en.wikipedia.org/wiki/Thames_Tideway_Scheme

The Tunnel 3 project is famous. It featured in Die Hard 3: All Die Gold. 20 years ago.

A friend of mine is the Innovation Project Manager for Crossrail (strictly speaking it won't be called the Elizabeth line until it opens). There's a good interview with him which I think would be of interest to HN readers, especially the approaches TFL has been taking to encourage innovation, and the new technologies they've been using for the project: http://digitalconstructionnews.com/2016/02/10/dcn-talks-to-w...

So does the new name ("Elizabeth line") imply that this is an expansion of the Underground - rather than a separate system? I know it sound like just semantics, but the DLR system for example is definitely quite distinct from the Underground, and I would like to know whether Crossrail will be too.

Crossrail seems to be original name for the Elizabeth Line, in case anyone else was confused by this comment. I'm guessing it will be part of the system, by sharing stations with the existing lines, but the platforms will be at different levels.

http://www.crossrail.co.uk/news/articles/crossrail-to-become...

Sorry, I was assuming readers knew about Crossrail - which was presumptive. Note that the DLR shares stations with the pre-existing Underground system, and has platforms at different levels, but is still considered a separate system not part of the system.

I think the desire to see the greater system decomposed into various properly named subsystems in the most coherent way possible is something that is characteristic of a software development mindset.

As far as I know, Crossrail is the name of the project whilst the Elizabeth line is the name of the actual line. The Elizabeth line seems to be not quite an extension of the underground.

This video clears it up somewhat [1].

[1] https://www.youtube.com/watch?v=XaBBg6Cyv9Q

Thanks, love this guy's passion. Summary of his position: No it's not a new underground line.

It's "normal" railway. Big trains, which continue onto the national railway network after leaving the tunnel.

Visitors to London especially don't need to care about this, and the name tells then to treat it like the other underground lines: there will be trains every two minutes, and a special ticket isn't required.

Also, Crossrail 2 is being planned.

> a special ticket isn't required.

Excellent, I've been trying to figure this out; whether I will be able to just jump on/off using my debit (or Oyster) card as I currently do on the over/underground.

Any idea how far out of town this ticketing system will be usable? Will someone in Reading be able to use a contactless card without having to buy a paper ticket?

> Excellent, I've been trying to figure this out; whether I will be able to just jump on/off using my debit (or Oyster) card as I currently do on the over/underground.

Note that you can also use contactless or Oyster on National Rail within the zones, e.g. King's Cross to Alexandra Palace or Moorgate to Finsbury Park.

> Any idea how far out of town this ticketing system will be usable? Will someone in Reading be able to use a contactless card without having to buy a paper ticket?

At the moment no. One would hope that common sense will prevail.

People will be able to use contactless and oyster once the Reading side of the system is taken over by TfL in a year or so.

If I recall correctly, this is already the case on the other side of Crossrail (Shenfield/Brentford). It's also been introduced at Gatwick Airport recently.

You recall correctly - the Shenfield part has been switched on for Oyster/contactless

It has interrunning with GEML and GWML, so a separate system. As TfL basically owns most of it, it is co-branded the same way Overground and DLR are too.

There are tons of videos available about Crossrail. It's a full sized (for the UK) electrified railway, with trains running above ground out to London's eastern and western suburbs.

Main site: [1]

[1] http://www.crossrail.co.uk/

All stations wheelchair accessible!

Your city may be different but wheelchair accessible stations are a rarity in London.

I want to know about the tunnelling machine. It was boring, but I think it's interesting!

The video at the bottom of the page goes into great detail on the machine and was not boring at all! :)

I had the privilege to visit the dig for Lyon's Caluire tunnel (ø9,8m though relatively short) during construction, and walk the length of the TBM as part of the visit, it was impressive as hell.

Well, I wouldn't call its boring boring.

> Before I was allowed down into the building site, I had to be shown what to do in case of emergency. Basically, "run away from the smoke if you can."

I met a guy at an after work thing a few years back, somewhere in the city, who said he worked with contingency planning for TfL. I asked him, what's the plan if there's a fire in the tube, one of the older lines where you're deep, deep underground, and there's heavy smoke development? His answer wasn't very re-assuring: "we pray."

Since that day I very rarely, if ever, take the tube anywhere. If I do I make sure it's on off hours when there aren't as many people on board or in the stations. Irrational fear, for sure, but coupled with the extreme amounts of people you may find, with people literally jammed up against the walls, I figure I'd rather spend a few more bucks on a cab, or just spend more time walking.

(Also the signs in various stations, King's Cross for instance, commemorating the victims of accidents and/or attacks aren't really re-assuring.)

    > Also the signs in various stations, King's Cross for
    > instance

Which happened in 1987.

Back in the days when escalators were made of wood, often had piles of inflammable litter built up behind them, and still had smokers flicking their smoldering cigarette butts all over the place.

There was a huge investigation into the causes of the King's Cross fire, and many changes implemented as a result [0]. The investigation even led to the discovery of the Trench Effect [1] "a combination of circumstances that can rush a fire up an inclined surface".

[0] https://en.wikipedia.org/wiki/King%27s_Cross_fire

[1] https://en.wikipedia.org/wiki/Trench_effect

That seems especially irrational if your alternative is road transport. People die every day from that. No passenger has died since 1987 on the Underground, except with the terrorist attacks. Even those didn't cause fires.

I would not consider it to be "one of the world's largest construction projects".

Ok. What's bigger that we might be interested in?

Gotthard base tunnel?

https://en.wikipedia.org/wiki/Gotthard_Base_Tunnel

I think it's okay for the second or third or even tenth largest project to be called "one of the world's largest projects".

FWIW, Crossrail is on this list of the 25 "most impressive" projects - http://www.popularmechanics.com/technology/g2121/the-worlds-... .

https://en.wikipedia.org/wiki/List_of_transport_megaprojects describes it as a "megaproject", and I can agree that everything which is a megaproject is one of the largest construction projects in the world.

Looking at the list of projects which are "under construction", and ordered by cost, Crossrail is #6 at US$25B and the GBT is #10 at US$10B.

Gotthard base tunnel: 4 million man hours http://edition.cnn.com/2011/WORLD/europe/11/23/gotthard.base...

Crossrail: 20 million man hours three years ago http://m.londonlovesbusiness.com/business-news/london-transp...

I'd love to see some more reliable figures, though.

Crossrail is at 100 million working hours so far, with 10,000 people working across over 40 construction sites, according to http://www.crossrail.co.uk/news/crossrail-in-numbers (which also describes it as "Europe's largest construction project").

Longer and deeper, sure, but Crossrail is a whole other level of complexity due to being built under of one of the world's largest and most congested cities.

Crossrail is the 4th most costly 'megaproject' involving transport both under construction and 4th including all completed projects. There isn't any way to look at it where it isn't one of the world's largest construction projects unless you start looking at space stations and if cities were 'megaprojects'

[1] https://en.wikipedia.org/wiki/List_of_transport_megaprojects

It wasn't mentioned that it will cost 25 billion - which btw is a ridicilous high number in comparison to other tunnel projects. Also for example the Gotthard base tunnel or the Brenner base tunnel are longer and therefor 'larger' then those described in the article.

Even looking at Gotthard tunnel is rather bad because it's just a tunnel though in very difficult conditions and large as you say is a bad comparison against a new railway network under a densely populated city.

Crossrail is large in the context it has new stations, depots, extensions, trains, and the very large amount of traffic it is expected to take under a very short construction period.

Looking at the entire picture doesn't make the number seem ridiculously high. If it seems to high you need to look at where it's all going its not just for a tunnel.

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