Elizabeth Line (CrossRail) opened 24th May 2022

Because the primary reason for the PEDs below ground is to regulate air movement, which is obviously very different above ground. Retrofitting PEDs is also not simple - in addition to being expensive they are tall, heavy and top-heavy (the motors are at the top so they aren't in the way of passengers). This means that the platform needs rebuilding as the outdoor platforms are roughly ⅂-shaped (i.e. there is an overhang so there is a gap between the train wheels and the platform edge), in at least some cases that wont be a simple as just building a new wall directly below the platform edge to take the additional weight as the foundation/viaduct isn't designed to be load-bearing at that point. This means you have to rebuild the foundations/strengthen the viaduct - possibly moving drainage and/or cables (power, signalling, communications, etc) out the way first (and to do that you might need to construct somewhere else to put them first, possibly after having redesigned your track drainage system).

Once you've done all that and rebuilt your platform (none of which you can do while trains are serving that platform and nearly none of it can be done while trains are running on that bit of track), you can start to install your PEDS (which is the easy bit). Although you might have to move the sopping point slightly as that's more flexible than the placement of the doors in the PEDs. Changing the stopping mark requires adjusting the ATO profile (I honestly have no idea how big or small a job that is) and/or adjusting signal sighting, possibly also moving CSDE loops, etc.

Finally you have working PEDS (assuming you've remembered to weatherproof them, likely adding more weight) you have to train your station staff in their use and what to do when they break (which they do) and make sure that there are sufficient staff such that if the PEDs do break them doing their job doesn't leave other essential parts of the station uncovered. You also have to maintain them (and that weatherproofing probably makes that a bit more complex and/or time consuming, and thus expensive and potentially disruptive). Remember when I said PEDs were expensive - that was just for the physical equipment - you have to factor in all the installation, maintenance and disruption costs as well.

PEDs still aren't cheap for a new build station but given the entire platform area is designed for PEDs from the start there are none of the modification costs and none of the disruption caused while an operational track is out of use they are cheaper. However you still have to work out the cost-benefit ratio and outdoors the only real benefit is keeping people off the track (which is only a minor, incidental benefit below ground) - especially if the ends of the platforms are not enclosed.

It might be interesting to note that Paris managed to retro-fit platform doors to historic subterranean Metro stations without significant closures - these were half-height doors designed to keep people off the track but not to block air flow.

cophagen had open above ground stations execpt airport had no platform edge doors but sometime around 2013 to 2018 i think they started fitting them on above ground stations - that meant no line closure just had single tracking around work site

airport has full platform edge doors

so also can we go back on topic?

I struggle to think where that would be possible on the Tube - all of the recent signalling is uni-directional and many crossovers were removed at the same time.

CrossRail press release:
www.crossrail.co.uk/news/articles/update-on-progress-to-complete-the-elizabeth-line-1#

Rather confirms what was said in the London Reconnections article at the end of last month.

It comes as no surprise that TFL are focusing on getting open those sections of the line which will bring in extra income - rather than relocate it.

Harking back to post #0001 on this thread we have already gone steaming past the first autumn 2019 "delayed opening date". I am sure it is too late to jump ship but it does seem that getting rolling stock to work with numerous incompatible signalling systems was always going to be a challenge. With hindsight I wonder if they really should have chosen to just adopt a signalling system already proven in use on either the west or east end of the core.

There are still no estimates when Bond Street and Whitechapel stations will be complete. What is causing the delays here at present?

I suppose this was inevitable given the state of events, nonetheless, the obliteration of design standards continues...

Brentwood National Rail station by bowroaduk, on Flickr

It should be TfL not TFL

I'm hoping that when the Elizabeth line finally opens the TFL RAIL strip comes off to reveal Elizabeth underneath

Some more photos, showing progress (even though the trains are not travelling anywhere new)

All views, Chadwell Heath, Monday 2nd December 2019.


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I am guessing here... remove a few screws and the full route is revealed (or will it show the Reading route which commences in a few weeks from now as a separate service?)

The platforms which will usually be served by Crossrail trains have a purple stripe, the others get nothing.
But this is a four-track railway and especially at weekends it can and does happen that one pair of tracks is closed, so therefore sometimes Crossrail trains will use the 'other' platforms.


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