400m platforms at Glasgow Central?

[Nottingham59]

[Crayon alert!] Could space be found for 400m long platforms at Glasgow Central?

When HS2 phase 1 starts, the fastest route from London to Edinburgh will be via HS2 phase 1 and Carlisle. So I'm expecting England-Scotland passenger traffic via Carlisle to grow strongly over the next twenty years, especially if they build phase 2a to Crewe.

But the WCML is limited by the constraints from running mixed traffic on a two-track railway over Shap and Beattock. One way to maximise capacity, without the expense of four-tracking parts of the route, would be to optimise the timetable by flighting pairs of 400m trains one after the other, one going non-stop to Edinburgh and one to Glasgow.

Edinburgh Waverley already has two platforms that can handle 400m trains. (Discussed here: https://www.railforums.co.uk/threads/400m-platforms-at-edinburgh-waverley.269975/ ). So this thread is to consider how it would be possible to accommodate 400m HS2 trains at Glasgow.

Central is a very awkward site with listed buildings in Union Street and Jamaica Street restricting growth on the East side of the station. But there is the length available to accommodate 400m trains by extending platforms over the river. From the buffer stops to Oxford Street across the river is 635m, as shown in the Google map extract below (where East is to the top).



Platform 11 at GLC is already 353m long, and there is space to extend P11 and P12 to 420m simply by building in the space between Line F and Line 6 that is already there on the bridge across the river. But this length would be completely unusable by HS2 trains due to the impossibly narrow neck between platforms 11 and 12 going over Clyde St / Broomielaw Road.

So how could they build 400m platforms?

Space where the station could expand are outlined in red here.



My first thoughts are sketched in the diagram below:

• Double the width of the bridge across the river. Sufficient to extend one or two island platforms over the water and with two new tracks to carry WCML slows. Demolish the unlisted Leonardo Hotel in Jamaica Street, but not the Category A listed buildings at No36, or the Category B at No42-44.
• Keep P1 - P4 where they are now, but all a similar length, connected across the river to the WCML No1 and No2 sidings (shown in Green). If traffic projections warrant, continue six WCML tracks to Eglinton Street Junction, where the Cathcart Circle lines diverge.
• Remove tracks 6 and 7, and create a new 420m island between P5 and P8 (dark blue), which extends across a widened river bridge.
• Remove tracks 10 and 11, and create a new 420m island between P9 and P12, also extending across the river.
• Keep platforms P13, P14, P15 as they are now (orange), to serve Cathcart Circle and Ayr Line trains.
• If required, build up to three new platforms P16-18 between P15 and Oswald Street, to the West of the station, perhaps with a replacement car park above (navy blue).

This would of course be a major undertaking and may be impossible because of the way that the train shed is supported. I don't know Central station at all and can't find many images of the interior of the station to show the layout of the roof and the separate sections of the building, so this may all be wildly impractical.

Alternatively, they could just keep to the plan and split HS2 trains at Carlisle.

Anyway, those are my thoughts. Any comments or (constructive) criticism welcome!

 

[Halifaxlad]

Well 300m trains would be better!

 

[Falcon1200]

Keep P1 - P4 where they are now, but all a similar length, connected across the river to the WCML No1 and No2 sidings (shown in Green). If traffic projections warrant, continue six WCML tracks to Eglinton Street Junction, where the Cathcart Circle lines diverge.

There was once an additional bridge over the Clyde east of the remaining one, reinstating this would certainly allow Platforms 1 and 2 to be extended; Would any more than 2 superlong platforms be necessary?!!

 

[Railsigns]

A detailed Glasgow Central Capacity Study report was produced about ten years ago, which explored a range of options to enhance capacity and to provide platforms for 400-metre trains.

 

[Nottingham59]

A detailed Glasgow Central Capacity Study report was produced about ten years ago, which explored a range of options to enhance capacity and to provide platforms for 400-metre trains.

that would be interesting to see. It's not at its published location and I can't find it online. Do you have a link by any chance?

There was once an additional bridge over the Clyde east of the remaining one, reinstating this would certainly allow Platforms 1 and 2 to be extended; Would any more than 2 superlong platforms be necessary?!!

You may well be right, but the island between platforms 1 and 2 is very curved and gets very narrow. I feared it would not pass modern safety standards if it were lengthened to handle 2 x 1100 passengers trains at the same time. But that might be the only affordable way to let Glasgow get a proper HS2 service.

EDIT
I don't know the station layout at all. Is there scope to have the concourse at ground level, and extend the tracks beyond the current buffer stops all the way to the buildings that front onto Gordon Street? Judging from Openrailwaymap, that could add another 50m to the lengths of platforms 1-8.

 

[Falcon1200]

I don't know the station layout at all. Is there scope to have the concourse at ground level, and extend the tracks beyond the current buffer stops all the way to the buildings that front onto Gordon Street?

That would entail a lot of demolition, so I don't think would be acceptable, or allowed,

 

[Nottingham59]

That would entail a lot of demolition, so I don't think would be acceptable, or allowed

Thanks for the responses.

So basically it seems the only practical way to get 400m trains into Glasgow Central is to extend the existing platforms P1 (279m) and P2 (292m), by 140 metres over the river, using the previous alignment where the bridge columns are still in place.



I wonder if a platform extension like that would be permitted under current standards? It would be possible to make the platform island a bit wider towards the river to accommodate emergency exits down to Broomielaw Street, which would help the safety case. Would a southern entrance to the station be useful here too?

I'm guessing one platform could handle 2tph, which should be plenty for Glasgow for a decade or two. With the second platform available as a spare if needed.

A new twin-track viaduct costs around £200M per km. This new viaduct would around 400m long to connect into the WCML tracks across the river, but would be twice as wide as a plain track. So perhaps twice 0.4 x £200m, around £160 million? To my untrained eye, it looks like it could be a relatively straightforward construction job, though I don't suppose the existing columns would be usable.

For info costs discussed here:

What is the current cost of building a new railway in the UK? I'm thinking about the total cost, not just the civil engineering. There's a number of references I can find. Are there any better sources?

• East West Rail Central Section options Central section capital cost estimate (14.08.2019) estimated £60m per route km in 2017.
• The cost of HS2 phase 2a is now suggested at £7bn for 59km over open countryside. That's £120m/route km.
• The HS2 civil engineering contract C1 to design and build the 3.4km Colne Valley Viaduct plus 15.8km of twin-bore 9m diamter Chiltern tunnel was awarded to ALIGN JV in 2017 for £965million. Even after inflation, that implies less than £50m/km to bore a single tunnel.
• HS2 Phase 2bWest was supposed to cost £17bn for the station and 15km tunnel in Manchester, plus (I think) 5km tunnel under Crewe and 35km of open line. Suggests tunnelled city line costs perhaps £500 per route km.

These are therefore my best guesses for the following, in £million per Route kilometre, with examples of where these might apply.

• £50m: Upgrading functional goods line to express passenger standards (e.g. Ditton Freight Line to Warrington Low-Level)
• £100m: 2-track 100mph railway on an old extant alignment (e.g. Warrington to Lymm)
• £100m: New unelectrified 2-track railway over open countryside (e.g. EWR Bedford-Cambridge)
• £120m: New Highspeed line across open country (e.g. HS2 phase 2a)
• £200m: New viaduct over open country (e.g. Colne Valley HS2)
• £200m: Cut and cover tunnel in countryside (e.g. HS2 green tunnels)
• £300m: Bored twin tunnel under open country
• £400m: Bored twin tunnel under city

Costs for other construction (guesses)

• £50m: Tunnel Portal
• £200m: New halt on mainline (2x260m platforms, like Winslow)
• £1000m: New station on High Speed Line (4x400m platforms plus through lines, like Airport HS)
• £2000m: 6 platform HS terminus, (e.g. HS Piccadilly)

EDITED

• £20M: New halt on mainline (e.g. Camp Hill line)
• £400M: New station of High Speed Line (4x400m platforms plus through lines, like Airport HS)
• £1000M: 6 Platfrom HS terminus (e.g. PHS iccadilly)

What do others think? Are these estimates reasonable?

 

[Halifaxlad]

So basically it seems the only practical way to get 400m trains into Glasgow Central is to extend the existing platforms P1 (279m) and P2 (292m), by 140 metres over the river, using the previous alignment where the bridge columns are still in place.

Why not reinstate the missing bridge, slew the lines over and extend the platforms on the Western side of the station ?

 

[Nottingham59]

Why not reinstate the missing bridge, slew the lines over and extend the platforms on the Western side of the station ?

Could be a great idea, but would cost more. Platforms on the Western side of the station would be best for the Ayr lines and the Carhcart Circle, which diverge off to the West.

But if we're building more tracks, then the WCML would benefit from keeping two fast and two slow tracks all the way across the river. (Currently the fast and slows merge at Eglinton Street Junction.) But that would mean keeping the slows to East side of the staiton, and having the WCML fasts in the middle somewhere.

I'll see how that might look later, though it would involve a lot more construction within the train shed.

EDIT
What frequencies do the Ayr, Cathcart and WCML slows carry? And what length trains?

 

[LNW-GW Joint]

The HS2 plan was never to run 400m trains to Scotland via Preston.
The plan was to run combined 400m Glasgow/Edinburgh trains to Carlisle and divide there, with separate 200m trains continuing to Glasgow and Edinburgh.
That was the plan after HS2 (west) reached Golborne - there won't be capacity on the WCML otherwise.
The deletion of the Golborne connection from the Crewe-Manchester bill left the Scottish plan (and the 400m platforms at Preston and Carlisle) in limbo.

With the cancellation of Phase 2 entirely, we don't even have 400m platforms at Crewe now, either.
So at the moment London-Edinburgh will stay on the ECML, even if quicker journeys became possible via HS2 Phase 1.
ECML upgrades were promised to compensate for the axing of HS2 services to Leeds, which would also benefit Edinburgh, but that's another Gordian Knot to unravel.