HS2 Old Oak Common

[kevin_roche]

I had been expecting to see this in the HS2 Construction thread but it has been closed and I can't find another thread that is suitable.

HS2 contractors make progress on station box, piling and utilities at Old Oak Common | New Civil Engineer

Work to construct the station, which will be the largest built in the UK in one stage, has accelerated during 2022 and the progress made on site

www.newcivilengineer.com

HS2 contractors make progress on station box, piling and utilities at Old Oak Common​

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Work to construct the station, which will be the largest built in the UK in one stage, has accelerated during 2022 and the progress made on site is showcased in a new video (above).

HS2’s station construction partner for the station is Balfour Beatty, Vinci Systra joint venture (BBVS JV).

Excavation works in the station box, where the platforms for the new high speed trains will be constructed, have been rapidly progressing with over 70,000m3 of London Clay already removed. The box is being excavated using a top-down construction method which allows the ground floor slab to be poured before large excavators are used to remove earth from underneath.

They claim that they are making good progress but I thought they should have done more by now. My notes from earlier had Start construction of Old Oak Common’s station for conventional trains. - July 2022. But there is no sign of that yet.
Does anyone know when work is now planned to be started on the GWML part of the station?

 

[Yindee8191]

I had been expecting to see this in the HS2 Construction thread but it has been closed and I can't find another thread that is suitable.

HS2 contractors make progress on station box, piling and utilities at Old Oak Common | New Civil Engineer

Work to construct the station, which will be the largest built in the UK in one stage, has accelerated during 2022 and the progress made on site

www.newcivilengineer.com

They claim that they are making good progress but I thought they should have done more by now. My notes from earlier had Start construction of Old Oak Common’s station for conventional trains. - July 2022. But there is no sign of that yet.
Does anyone know when work is now planned to be started on the GWML part of the station?

Work on the GWML station is somewhat underway, but it’s just prep work at the moment. I think the in your area map has a couple of items about moving OHLE masts and building retaining walls this year, in preparation. Proper visible work is to start in 2023, according to posts in the old thread.

 

[Sonik]

I think perhaps the progress at OOC is just not terribly visible.

There has been a lot of work to do with preliminaries, setting up logistics etc. and what work has been done on the build is mostly below ground so there's not much to see.

 

[Bald Rick]

They claim that they are making good progress but I thought they should have done more by now.

They are bang in their revised programme, and have been for well over a year.

it’s a huge job, and not everything is visible.

 

[Snow1964]

Ian's visits has done an article, with lots of photos

See inside HS2’s new Old Oak Common railway station

One of London's largest construction sites can be found at Old Oak Common in west London, where a huge new railway station is being built.

www.ianvisits.co.uk

One thing that I am confused about is the first diagram, refers to 250m conventional platforms, won't these be too short for pair of 5car IETs at 260m ?

 

[59CosG95]

Ian's visits has done an article, with lots of photos

See inside HS2’s new Old Oak Common railway station

One of London's largest construction sites can be found at Old Oak Common in west London, where a huge new railway station is being built.

www.ianvisits.co.uk

One thing that I am confused about is the first diagram, refers to 250m conventional platforms, won't these be too short for pair of 5car IETs at 260m ?

I suspect the 250m is a ballpark figure, and that the final design will be slightly longer.

 

[Martin222002]

I suspect the 250m is a ballpark figure, and that the final design will be slightly longer.

Given that I'm almost sure that HS2 platforms are speced to be 415m long for the 400m trains, and the diagram in question only says 400m, I'd take that 250m figure with a pinch of salt too.

 

[bib]

Someone has been on site and got some footage

a nice overview of the OOC site and the scale of the crossrail depot

 

[Fazaar1889]

HS2 OLD OAK COMMON

Some new footage of the construction site. I have no clue what I'm looking at, but it looks like something for sure. I assume it's the victoria cross over box thing?

Idk how that works tbh

 

[plugwash]

No idea what "victoria cross" means in this context, but I assume the beams over the box are to prevent the sides collapsing in.

 

[LNW-GW Joint]

No idea what "victoria cross" means in this context, but I assume the beams over the box are to prevent the sides collapsing in.

The Victoria Road Crossover Box, very likely.
It's where HS2 from the north fans out underground into the 6-platform station.
It is also where TBMs will be launched later this year to bore the eastern section of the Northolt Tunnels.

 

[bib]

Some more info on the HS2 page:

Victoria Road Crossover Box and Ancillary Shaft - HS2

Victoria Road Crossover Box, near to Old Oak Common in West London, will allow HS2 trains to switch tracks underground on their approach into the new superhub station.

www.hs2.org.uk

The box will be 130m in length and 24m deep complete with 1.5m thick walls constructed by diaphragm piling method, with top and intermediate levels of reinforced concrete props.

There's also a video there from the start of November showing the first of the support walls being installed, so there seems to have been quite a bit of progress since then, guessing it's close to full depth at the western end

 

[Fazaar1889]

The Victoria Road Crossover Box, very likely.
It's where HS2 from the north fans out underground into the 6-platform station.
It is also where TBMs will be launched later this year to bore the eastern section of the Northolt Tunnels.

I genuinely don't understand the point of the cross over box. I've looked at the website and I still don't get it. Wdym by HS2 trains fan out into the platforms? Aren't the platforms being built somewhere else on the site?

 

[Snow1964]

I genuinely don't understand the point of the cross over box. I've looked at the website and I still don't get it. Wdym by HS2 trains fan out into the platforms? Aren't the platforms being built somewhere else on the site?

It's where the junction at end of the platforms goes in a wide covered trench (the box). It tapers from 2 tracks (the bored section to Northolt) to the wide section where each track serves a platform. Obviously don't want any columns where tracks go.

 

[Fazaar1889]

It's the junction at end of the platforms, in a wide covered trench (the box)

What does it connect to?

 

[Jamiescott1]

Ianvisits states a large GWML blockade next Christmas due to OOC works

 

[LNW-GW Joint]

The crossovers allow access to all platforms and will permit trains to reverse at OOC in any platform.
The crossover box is somewhat west of the HS2 station site and is also a ventilation/access shaft, and will have short tunnels into the HS2 station platforms (I think).

 

[Fazaar1889]

The crossovers allow access to all platforms and will permit trains to reverse at OOC in any platform.
The crossover box is somewhat west of the HS2 station site and is also a ventilation/access shaft, and will have short tunnels into the HS2 station platforms (I think).

OK I kinda get it now. How accurate is this OC diagram then? The lines are all tracks and the yellow one leads to the box

 

[The Planner]

Ianvisits states a large GWML blockade next Christmas due to OOC works

And a good few more after that as well.

 

[bib]

If you look at the HS2 - 'in my area' map it shows the track layout - the crossover allows trains from either of the 2 tunnels to access all 6 platforms by 'crossing over' into the other tunnel for the short section approaching OOC, otherwise it looks like the station throat only allows access to 4 platforms depending on whether you are arriving in the northern or southern of the two tunnel bores.

I'm not 100% sure but I think the crossover box is only needed to enable OOC to operate as a terminal station to allow trains to be turned around at any platform, since there isn't one on the other side of the station heading towards Euston. Presumably through trains will continue eg in the northern tunnel after OOC and then the crossovers at the Euston approaches will allow them to be reversed into in the southern tunnel when heading back the other direction.

 

[Fazaar1889]

If you look at the HS2 - 'in my area' map it shows the track layout - the crossover allows trains from either of the 2 tunnels to access all 6 platforms by 'crossing over' into the other tunnel for the short section approaching OOC, otherwise it looks like the station throat only allows access to 4 platforms depending on whether you are arriving in the northern or southern of the two tunnel bores.

I'm not 100% sure but I think the crossover box is only needed to enable OOC to operate as a terminal station to allow trains to be turned around at any platform, since there isn't one on the other side of the station heading towards Euston. Presumably through trains will continue eg in the northern tunnel after OOC and then the crossovers at the Euston approaches will allow them to be reversed into in the southern tunnel when heading back the other direction.

View attachment 129673

Ah that makes sense. Thanks

 

[Snow1964]

If you look at the HS2 - 'in my area' map it shows the track layout - the crossover allows trains from either of the 2 tunnels to access all 6 platforms by 'crossing over' into the other tunnel for the short section approaching OOC, otherwise it looks like the station throat only allows access to 4 platforms depending on whether you are arriving in the northern or southern of the two tunnel bores.

I'm not 100% sure but I think the crossover box is only needed to enable OOC to operate as a terminal station to allow trains to be turned around at any platform, since there isn't one on the other side of the station heading towards Euston. Presumably through trains will continue eg in the northern tunnel after OOC and then the crossovers at the Euston approaches will allow them to be reversed into in the southern tunnel when heading back the other direction.

View attachment 129673

Yes, the crossover allows trains from North to use all 6 platforms, which allows it operate as a terminus. Normally would use the outer pair in direction of travel, with the centre pair being available from either direction. Obviously centre reversal platforms mean not blocking other trains.

From Euston could only reverse in centre pair of platforms (but not likely to be many terminating trains from there).

 

[LNW-GW Joint]

Ah that makes sense. Thanks

Your yellow line doesn't exist.
The box just allows an HS2 track fan to the west of the OOC station.

 

[hwl]

I'm not 100% sure but I think the crossover box is only needed to enable OOC to operate as a terminal station to allow trains to be turned around at any platform, since there isn't one on the other side of the station heading towards Euston. Presumably through trains will continue eg in the northern tunnel after OOC and then the crossovers at the Euston approaches will allow them to be reversed into in the southern tunnel when heading back the other direction.

It is also very much needed to extract the ex-Northolt TBMs and feed the tunnel segments delivered at Willesden to the Euston bound TBMs via the short tunnels under Old Oak Common lane and NLL

 

[LNW-GW Joint]

It is also very much needed to extract the ex-Northolt TBMs and feed the tunnel segments delivered at Willesden to the Euston bound TBMs via the short tunnels under Old Oak Common lane and NLL

I think the picture is more complicated.
As I understand it, the Victoria Road crossover box will launch the Northolt (east) TBMs and feed them with segments - those TBMs will emerge at Greenford Way.
I thought the same arrangement would apply to the Euston tunnels, but it seems a separate 853m Logistics Tunnel will be bored from the Atlas Road site (north of OOC) to the east end of the OOC station area.
This will then feed the Euston TBMs being launched from OOC east in 2024, from the Willesden site.
The gap between the TBM launch sites, encompassing the OOC station area, will be excavated without TBMs.
Happy to be corrected if I've got it wrong.

https://assets.hs2.org.uk/wp-content/uploads/2023/01/2211-FAQ-Euston-Tunnels-November-2022.pdf

Atlas Road Logistics Tunnel - HS2

To support the construction of the Euston Tunnels, SCSJV will build the Atlas Road Logistics Tunnel between the Atlas Road and the Old Oak Common Station site.

www.hs2.org.uk

 

[bib]

Oh that's interesting, haven't seen it mentioned before. Seems a quite expensive solution to what I assume is a logisitics problem with getting the tunnel segments into OOC.


Theoretically tunnelling should start soon, but given the lack of publicity I wonder if it has slipped

 

[SCDR_WMR]

It looks ready to receive the TBM so maybe only a slight slip if any.

 

[Snow1964]

Theoretically tunnelling should start soon, but given the lack of publicity I wonder if it has slipped

It is not uncommon to only have a publicity launch after the machine has been commissioned and cut and installed a few test rings of segments. When launching from a shaft or partly covered box usually can't photograph the whole machine anyway.

 

[Dave_Cardboard]

The temporary "logistics tunnel" also avails the removal of spoil from the Euston tunnels avoiding using trucks on the local highways - IIRC it's being taken to the Willesden Euroterminal sidings to thence be removed by train.

Still new to trains.

If you search for the term "Scissor Crossover" you will probably find some good explanations of this particular type of track layout. It's often used when there is need for a pair of crossovers between lines facilitating A to B and B to A, but space is tight and a compact layout is needed instead of two separate sets of "simple" crossovers. For example, there's a bunch of them on the approaches to some the terminal platforms at London Bridge, but there are plenty of examples elsewhere.

It occurred to me that the crossovers west of OOC would also facilitate "wrong way running" from all OOC platforms northwards in case either line/tunnel needed to be closed for any reason in the future - though looking at my HS2 track diagrams (from about 2015) it's a long, long way before there's opportunity to cross back again!

 

[Snow1964]

Oh that's interesting, haven't seen it mentioned before. Seems a quite expensive solution to what I assume is a logisitics problem with getting the tunnel segments into OOC.

View attachment 129705
Theoretically tunnelling should start soon, but given the lack of publicity I wonder if it has slipped

The latest document on works has following (page 8)

Preparation for works to build the Northolt Tunnels East from late 2023. These works will include delivery and assembly of the tunnel boring machines (TBMs) and construction of the launch areas for the TBMs below ground;
 Launch and operation of two TBMs to build the Northolt Tunnels East, westbound from the Victoria Road Crossover Box from late 2023; and
Start of work to build tunnels from the Victoria Road Crossover Box to the Old Common station site is planned from late 2023.

https://assets.hs2.org.uk/wp-content/uploads/2022/12/Winter-2022-Construction-look-ahead-Old-Oak-and-North-Acton.pdf

Ianvisits states a large GWML blockade next Christmas due to OOC works

At the London end of the station, the new 6 track high speed station goes partly underneath the existing tracks. A trench needs to be dug for the 1.5m wide wall (diaphragm wall). In very simplistic form dig out a short length with what looks like a grab bucket and then fill it will concrete, doing it in small bits so hole doesn't cave in. The civil engineering process is rather more complicated than a quick description.

Clearly can only dig this if you lift track out of the way, then put it back again afterwards.

I don't know if this is happening at Old Oak, but normally the reinforcing rods are left protruding out of the concrete wall sections which finish about metre below surface, they are temporarily covered with wooden box or similar, and temporary fill put on top. At later date they are uncovered, reinforcement rods added to link the protruding vertical reinforcement and a huge capping slab cast in one large concrete pour. These pours will have parts that run all the way to other side wall to shop the two sides moving towards each other. For very long side these pours will be done in sections. My guess is it is these pours that will be done during the big closures as need access to a wider width, so need to tempo remove multiple tracks.

Once all the capping pours are done, track is back (although will probably have a speed restriction) and then station is built top down, (just dig out under the big concrete roof) adding more transverse props at intervals to keep sides apart. Eventually will get a base slab, and then be built up inside, although intermediate levels eg concourses might be cast as dig progresses downwards.