HS2 TBM Progress

[absolutelymilk]

Great! Are there many more shafts for either set before they reach the end?

 

[Snow1964]

Updates today for all four Northolt TBMs.

Northolt West (21 days to Aug 12):
Shushila 6337m (+515m), Caroline 5841m (+150m).

Northolt East (7 days to Aug 9):
Emily 1559m (+108m), Anne 1190m (+0m).

So Shushila looks to be moving quickly (24m/day) after negotiating the Mandeville Road vent shaft, while Caroline seems to have reached the shaft.
Emily is moving well (15m/day), but Anne is stopped for some reason.

This document on works suggests Caroline was expected at Mandeville Road shaft early August (page 13)

https://assets.hs2.org.uk/wp-content/uploads/2024/07/Hillingdon-August-2024-Construction-look-ahead-Align-SCS-002.pdf

== Doublepost prevention - post automatically merged: 12 Aug 2024 ==

HS2 has issued update on Chiltern tunnels (lots of photos) of headhouses, passages etc, also diagrams of the porous sections (to minimise sound and air pressure)

https://assets.hs2.org.uk/wp-content/uploads/2024/08/2405030-Chiltern-Tunnel-Summer-2024-V7.pdf

 

[LNW-GW Joint]

Great! Are there many more shafts for either set before they reach the end?

Mandeville Road is the last one for the Northolt West pair before they reach the exit at Greenford Way by year end.
The Northolt East pair have one intermediate shaft at Westgate, but they are a fair way off that yet.
Bromford also has one intermediate shaft at Orton Way, which is where the first TBM (Mary Ann) is now, while the second (Elizabeth) still has a long way to go.
There are also the cross-passages to complete, although these were well in hand in the Chiltern Tunnel when the TBMs finished their drives.
Then there are various headhouses to complete on the surface.

 

[Geogregor]

Lots of tunnel segments at Ruislip:


P1870451 by Geogregor*, on Flickr


P1870452 by Geogregor*, on Flickr

 

[LNW-GW Joint]

Each stack of 7 segments makes one complete tunnel ring of I think 2 metres in tunnel length.
Each TBM will consume 10 stacks in a daily linear progress of 20m which is typical of a good day.
So the picture represents not much more than a day's worth of tunnelling by the two TBMs.
These segments will be transported more than 6km through the completed tunnel to reach the TBM cutting faces, increasing to 8km by the end of the job.
It certainly illustrates the physical and logistical challenges of building large-diameter rail tunnels.

 

[GRALISTAIR]

Each stack of 7 segments makes one complete tunnel ring of I think 2 metres in tunnel length.
Each TBM will consume 10 stacks in a daily linear progress of 20m which is typical of a good day.
So the picture represents not much more than a day's worth of tunnelling by the two TBMs.
These segments will be transported more than 6km through the completed tunnel to reach the TBM cutting faces, increasing to 8km by the end of the job.
It certainly illustrates the physical and logistical challenges of building large-diameter rail tunnels.

Wow, that puts it into context and is quite frankly, mind-blowing!

 

[Chonner]

There are quite a few what I assume to be components from the Euston TBMs being prepared on the surface at the east end of the Old Oak Common site. The larger crawler crane has been there a couple of weeks now and I guess is being used to lower them down into the station box.

 

[LNW-GW Joint]

Updates for 4 TBMs today.

In your area map - HS2

Search our interactive In Your Area Map to find information about current or planned HS2 construction works taking place across the route.

www.hs2.org.uk

Northolt East (10 days Aug 9-19):
Emily is at 1675m (+116m), Anne at 1265m (+75m).
Modest progress of 7-11m/day, but Anne is now on the move again after a stoppage.

Bromford (13 days Aug 6-19):
Mary Ann is at 3054m (+74m), Elizabeth at 1130m (+208m).
Mary Ann is past the 3km mark and Elizabeth, now beyond the 1km mark, is moving nicely at 16m/day after its slow start.

 

[Snow1964]

HS2 has revealed one Bromford tunnel has reached halfway point

The construction of HS2’s gateway to Birmingham takes a leap forward as the huge 125-metre-long tunnel boring machine (TBM) digging the first bore of the Bromford Tunnel reaches the halfway point.

The 1,600 tonne TBM, named ‘Mary Ann’ - the real name of Warwickshire-born author George Eliot - has excavated and built 1.75 miles of the first bore of the tunnel since it started digging from a large underground box in Water Orton last year.

Driving around 40 metres underground towards Washwood Heath in Birmingham, the TBM has excavated under the Park Hall Nature Reserve and River Tame and is now passing under Castle Vale. It will continue adjacent to and under the M6 before breaking through at Washwood Heath early next year.

An expert tunnelling team have been working around the clock on shifts to operate the TBM, which also builds the tunnel as it excavates. A total of 20,797 concrete segments will be put in place by the machine, making 2,971 concrete rings to form the tunnel.

The tunnel’s 47-metre-deep ventilation shaft at Castle Vale marks the halfway point of the TBM. The shaft, which is 18.6 metres in diameter, will feature cross passages which will eventually link to the two tunnels either side to provide ventilation, servicing and emergency access. A ‘headhouse’ will be built on top of the shaft, and the whole structure will be complete in 2027.

‘Elizabeth’, the second TBM – named after Dame Elizabeth Cadbury by local school pupils, started building the tunnel’s second bore in March 2024 and is due to finish her journey towards the end of 2025.

The two TBMs will remove 1.87 million tonnes of excavated material, which is being sifted at the on-site slurry treatment plant and reused on nearby sites at the Delta Junction, where a complex network of 13 viaducts is being built. HS2 has built dedicated roads between these construction sites, including an access off the M6/M42 link roads, in order to take lorries off public roads.

In preparation for the arrival of the TBMs at Washwood Heath, a huge earthworks operation has been completed by a team of 130 people to build the tunnel’s west portal, which at 22 metres below ground is the deepest of the four tunnel portals on the Midlands section of the HS2 route.

The portal is at the start of a 750-metre-long cut and cover structure, which is currently being excavated and built. This is where HS2 trains will emerge from the Bromford Tunnel and travel below ground level, before raising up onto a series of viaducts through Birmingham’s industrial heartland and into Curzon Street Station.

HS2’s tunnelling into Birmingham reaches halfway point

HS2’s giant tunnelling machine is halfway through its journey to build the 3.5-mile Bromford Tunnel The 1,600 tonne machine called ‘Mary Ann’ has excavated and built 1.75 miles of tunnel between Water Orton and Washwood Heath in Birmingham View and download photos, b-roll and YouTube video

mediacentre.hs2.org.uk

 

[Snapper]

There's been a media visit to the HS2 construction site at Bromford in Birmingham today. A few of us were there, so here's a blog and pictures. The irony? I travelled there from Manchester and returned via Leeds. The two sections of HS2 that have been mothballed/cancelled. On both routes the 'alternative' is...'Voyagers'.

https://paulbigland.blog/2024/08/28/rol ... derground/

 

[LNW-GW Joint]

More strong progress reported for TBM Shushila at Northolt West: it's at 6730m, +393m between Aug 12-29 or 23m/day.
Shushila is now located south of the Paddington Arm of the Grand Union Canal, with 1.1km to its Greenford Way finish.
However its partner Caroline is stopped at 5841m, so some maintenance would seem to be necessary at the Mandeville Road vent shaft.

Interesting that the media visit to Bromford was not accompanied by a positional update on the lead TBM Mary Ann, the subject of the visit.
The last position reported was on August 19.

 

[Snow1964]

New drone footage of the Chalfont St Giles ventilation shaft headhouse above Chiltern tunnel.

Looks like it has been made to look like a farm building or a farm shop, to blend in with other buildings nearby.

 

[LNW-GW Joint]

Another update at Bromford for Sept 2 (14 days from Aug 19):
Mary Ann is at 3204m (+150m), Elizabeth 1254m (+124m).

Steady progress, around 10m/day.
Mary Ann, after all the media attention last week, has now passed under the A452 dual carriageway and is about to pass under the River Tame again.

Interactive route map

Use HS2’s interactive map to explore the entire route of Britain’s new high-speed railway. Find present and upcoming works, tunnels, station locations and community updates — all in one easy-to-navigate map.

www.hs2.org.uk

Edit, Sept 3:
HS2 has announced that tunnel segment production for Northolt West, by Pacadar on the Isle of Grain in Kent, has now completed.
TBMs Shushila and Caroline still have around 3km of tunnel to build, so the supply chain still has around 6 months to run before they complete the job.
Pacadar produced 59129 ring segments for the 8km Northolt West tunnels.

HS2 tunnel segment casting complete at Isle of Grain factory

PACADAR UK, based on the Isle of Grain, have completed the casting of almost 60,000 concrete tunnel ring segments for HS2 They are being used to construct the Northolt Tunnel West which is almost 80% complete Segments transported from Kent to HS2’s site by rail, with each giant freight train...

mediacentre.hs2.org.uk

Production of concrete segments used to construct HS2’s 5-mile Northolt Tunnel has been completed in a major milestone for subcontractor PACADAR UK.
The company began work on the production of the segments in April 2022 and have completed the production of 59,129 segments, which make up 8,447 tunnel rings – seven segments per ring.

 

[LNW-GW Joint]

More steady progress at Northolt East: TBM positions for Sept 13 (25 days from Aug 19):
Emily is at 1978m (+303m), Anne is at 1660m (+395m).
This represents an average rate of 12.1m/day and 15.8m/day respectively.

Interactive route map

Use HS2’s interactive map to explore the entire route of Britain’s new high-speed railway. Find present and upcoming works, tunnels, station locations and community updates — all in one easy-to-navigate map.

www.hs2.org.uk

Edit Sep24:
TBMs at Bromford and Northolt East were updated in the last week.

At Bromford (Sep 18, 16 days from Sep 2):
Mary Ann was at 3394m (+190m), Elizabeth at 1374m (+120m).
Rates of 8-12m/day now seem typical here.

At Northolt East (Sep 23, 10 days from Sep 13):
Emily is at 2028m (+50m), Anne is at 1968m (+38m).
4-5m/day is a good bit less than the previous rates.

 

[LNW-GW Joint]

All four Northolt TBMs were updated today (Sep 30):

Northolt West (32 days since Aug 29):
Shushila is at 6939m (+209m), Caroline 5841m (+0).
Shushila has slowed in the last month (6.5m/day), while Caroline has been stopped for 7 weeks suggesting repairs are being carried out.

Northolt East (7 days from Sep 23):
Emily is at 2137m (+109m), Anne 1768m (+70m).
Steady progress.

Edit, Oct 1:
To round out the TBM updates, the Bromford TBM positions were updated today (13 days since Sep 18):
Mary Ann is at 3530m (+136m), Elizabeth 1636m (+262m).
This is the fastest rate Elizabeth has posted (20m/day).

 

[hwl]

All four Northolt TBMs were updated today (Sep 30):

Northolt West (32 days since Aug 29):
Shushila is at 6939m (+209m), Caroline 5841m (+0).
Shushila has slowed in the last month (6.5m/day), while Caroline has been stopped for 7 weeks suggesting repairs are being carried out.

Repairs being carried out and possibly combining with a coordinated staff summer break and remaining staff all being focused on the other TBM (Shushila)?
The segment logistics get progressively worse as the tunnel get longer so that may be the limiting factor for Shushila.

Northolt East (7 days from Sep 23):
Emily is at 2137m (+109m), Anne 1768m (+70m).
Steady progress.

The West and East segments are from different factories so segment supply shouldn't be an issue with East picking up pace a bit.

So potential completion:
Shushila between mid-November and mid-Feb depending on the best / worst average pace over recent months.
Caroline between 3-13 months from restart depending on best vs worst (not stopped) pace.
Is Shushila picks up pace again and finished quickly all the logistics supply could be focused on Caroline which should then be able to run at a reasonable pace.
As Caroline is stopped in a vent shaft is this potentially limiting some segment vehicle movements or other logistics?

Emily: mid-September 2025 at average pace since launch
Anne: mid-November 2025 at average pace since launch

You probably want at least 8 weeks to dismantle a TBM before the next one arrives in the same direction (this look fine for both directions) and possibly slightly longer before another in the other direction - which might start to be a problem if Caroline doesn't restart in the next 2months and proceed at a reasonable pace...

 

[LNW-GW Joint]

The mood music on boring the 8km Euston tunnels now seems to be positive again.
The go-ahead was reportedly imminent at the point the election was called, and it seems the same position has now been reached with the new government.
This is along with an apparent determination to complete the Euston rebuild and end the speculation about a permanent terminus at OOC.
Hopefully all with become clear in the Budget speech on October 30.

Reeves under pressure to agree new HS2 Euston leg ahead of Budget

Hopes are rising that HS2 will terminate in Euston

inews.co.uk

Rail minister Lord Hendy, the former head of National Rail and ex-chair of the Euston Partnership, is known to be a staunch supporter of terminating HS2 in Euston.
It comes as Transport Secretary Louise Haigh told the Evening Standard on Thursday that “clearly Euston is going to be part of the wider picture”, before adding: “We will be making a decision soon on the tunnelling and the development.”
Pushed on the issue, she said: “Nobody would have designed it in the first place to go between Birmingham and Old Oak Common and clearly some wider decisions have to be made in the future both imminently around Euston but also around the terrible situation that they have left us north of Birmingham, by worsening the capacity issues that already existed.”
Significant sums have already been spent on the Euston tunnel, not least on building tunnel-boring machines that are waiting for the Government to sign off on the tunnel.

 

[GRALISTAIR]

The mood music on boring the Euston tunnels now seems to be positive again.
The go-ahead was reportedly imminent at the point the election was called, and it seems the same position has now been reached with the new government.
This is along with an apparent determination to complete the Euston rebuild and end the speculation about a permanent terminus at OOC.
Hopefully all with become clear in the Budget speech on October 30.

Thank goodness commonsense is looking like it might prevail.

 

[AeM]

Just needs the link to HS1 to be completed for it to be a proper high speed railway!

 

[Snow1964]

Just needs the link to HS1 to be completed for it to be a proper high speed railway!

The HS2-HS1 link is currently in the dropped from being built category.

Although common sense would reinstate it as bound to be needed in the future and would be hugely expensive and difficult to add later.

Perhaps make 2 of the 7 platforms at Birmingham for International trains, along with opening the International platforms at Stratford. After all they have been / are being built (even if not fitted out), so why not put them to use as construction money is a sunk cost.

 

[zwk500]

The HS2-HS1 link is currently in the dropped from being built category.

Although common sense would reinstate it as bound to be needed in the future and would be hugely expensive and difficult to add later.

Already too far gone, AIUI. Old Oak Common box is basically complete, and the tunnel portals are designed without any provision for a future link.
Partly this is because HS1 has no provision for a future link anywhere you could reasonably connect HS2 to.

 

[DavidGrain]

Already too far gone, AIUI. Old Oak Common box is basically complete, and the tunnel portals are designed without any provision for a future link.
Partly this is because HS1 has no provision for a future link anywhere you could reasonably connect HS2 to.

I agree. I have just been thinking about it and the only way I can see would be to run in tunnel all the way to Stratford and make the junction just before Stratford International Station but this would not give a central London calling point and cause months of disruption to HS1.

 

[Snow1964]

I agree. I have just been thinking about it and the only way I can see would be to run in tunnel all the way to Stratford and make the junction just before Stratford International Station but this would not give a central London calling point and cause months of disruption to HS1.

The plan for HS1 - HS2 was to piggyback off the provision for a spur just west of where HS1 leaves the tunnel at Kings Cross.

Don't think it was designed for high speed, just linking the two routes just outside the termini. See link for the route plan (on 4 sheets). The HS2 junctions would be in underground (step plate style) junctions.

HS2 plan and profile maps: HS1 - HS2 link

These are the plan and profile maps for Phase One of HS2 between London and the West Midlands.

www.gov.uk

 

[zwk500]

Don't think it was designed for high speed, just linking the two routes just outside the termini.

160kph from OOC to Camden jn area, then 50kph from Primrose Hill to HS1 going by those sheets (Design speed is bottom row of the data table).

 

[jfowkes]

We were never in Schengen, which made border stuff hard enough to do pre-brexit. Now we've left the EU, and with no political appetite to rejoin, direct services from the rest of the UK to Europe aren't realistic. The staff and facilities you need at each terminal just make it too uneconomical compared to just making people transfer from Euston to St Pancras.

 

[chris2]

Those four sheets don’t appear to include the actual connection point from the HS2 up and down tunnels. The link tunnel seems to run for quite some way parallel to the up and down - presumably this adds significantly to its cost - but where does it actually comnect?

It looks like the current alignment of the HS2 tunnels is unchanged from this plan and therefore has left room for a third link tunnel in between if ever there was a desire to bore it in future. But presumably passive provision from the point of divergence isn’t included in the Euston tunnel design now…would it ever be feasible to add it later?

 

[swt_passenger]

Those four sheets don’t appear to include the actual connection point from the HS2 up and down tunnels. The link tunnel seems to run for quite some way parallel to the up and down - presumably this adds significantly to its cost - but where does it actually comnect?

It looks like the current alignment of the HS2 tunnels is unchanged from this plan and therefore has left room for a third link tunnel in between if ever there was a desire to bore it in future. But presumably passive provision from the point of divergence isn’t included in the Euston tunnel design now…would it ever be feasible to add it later?

The link tunnel was to be single track and the junctions were shown between up and down lines in the Old Oak Common station box drawing at the time, this drawing has been replaced with a version without the middle tunnel.

https://assets.publishing.service.gov.uk/media/5a7df2f7ed915d74e33ef109/C221-MMD-CV-DPP-010-201700_0.pdf

 

[chris2]

Ah right, so it actually runs all the way from OOC station in between the main up and down lines?

 

[swt_passenger]

Ah right, so it actually runs all the way from OOC station in between the main up and down lines?

Yes that was the plan. A reversible single line, it’s in red on the linked 2013 drawing which is the continuation of the other four ‘link’ drawings, but although the stub is still there on the 2016 drawing there’s nothing past the head wall of the station box.

 

[chris2]

Gotcha, thanks for digging that out.