HS2 TBM Progress

[Fazaar1889]

Despite the news that boring of the Euston tunnels has been paused for an indefinite duration, the Chiltern TBMs continue to keep the project afloat with good progress this week (18 April).
Florence and Cecilia are now at 10179m and 10138m respectively, moving at 26m per day, and now past the 10km mark.

so pretty much around 60% done. I've been wondering for a while, now that a few tunnels have been completed and this one should be done in the next couple years, when do they lay the tracks and the overhead wires and the rest? what else do they put down other than the tracks and wires?

 

[zwk500]

so pretty much around 60% done. I've been wondering for a while, now that a few tunnels have been completed and this one should be done in the next couple years, when do they lay the tracks and the overhead wires and the rest? what else do they put down other than the tracks and wires?

A lot of earthworks, drainage, all the signalling and comms cable troughing, structure cabinets, piling for OLE masts, etc, etc.

 

[LNW-GW Joint]

so pretty much around 60% done. I've been wondering for a while, now that a few tunnels have been completed and this one should be done in the next couple years, when do they lay the tracks and the overhead wires and the rest? what else do they put down other than the tracks and wires?

Much of the route, especially in soft ground areas near rivers, will be on low piled viaducts.
Some of that is in progress but not very visible yet.
There are also lots of cuttings and embankments, green tunnels and the rest.
I think it will be 2026 before any track is laid.
While the switches and crossings have been ordered (from Austria), the plain track hasn't - I imagine the steel plants are keenly awaiting the order.

 

[Fazaar1889]

A lot of earthworks, drainage, all the signalling and comms cable troughing, structure cabinets, piling for OLE masts, etc, etc.

I have no idea what half of that means but yeh, sounds complex. still a lot more to do then...

Much of the route, especially in soft ground areas near rivers, will be on low piled viaducts.
Some of that is in progress but not very visible yet.
There are also lots of cuttings and embankments, green tunnels and the rest.
I think it will be 2026 before any track is laid.
While the switches and crossings have been ordered (from Austria), the plain track hasn't - I imagine the steel plants are keenly awaiting the order.

Ah interesting. yeah 2026 sounds reasonable

 

[zwk500]

I have no idea what half of that means but yeh, sounds complex. still a lot more to do then...

Earthworks - all the cuttings and embankments,
Drainage - all the trackside drains to take water away from the trackbed and into the retention ponds, sewers or other management structures they have chose to use.
Cable troughing - the sunken channels along the trackside that will contain all the signalling and communications equipment HS2 needs, as well as any other cables.
Structure cabinets - the concrete bases for mounting the grey cabinets that will contain all the signalling, radio, and any other trackside equipment in them.
Piling for OLE - the big concrete bases to which the Overhead Line Equipment structures are mounted. These need to be drilled or hammered in along the trackside before the masts and gantries themselves can appear.

 

[Fazaar1889]

Cable troughing - the sunken channels along the trackside that will contain all the signalling and communications equipment HS2 needs, as well as any other cables.
Structure cabinets - the concrete bases for mounting the grey cabinets that will contain all the signalling, radio, and any other trackside equipment in them.
Piling for OLE - the big concrete bases to which the Overhead Line Equipment structures are mounted. These need to be drilled or hammered in along the trackside before the masts and gantries themselves can appear.

Ah thank you!

 

[Bald Rick]

Not forgetting some very, very carefully graded sub base on which the slab track will be laid. Tolerance in low figure mm I should imagine. Plus countless culverts and bridges under that.

 

[dosxuk]

Plus countless culverts and bridges under that.

Indeed - this is one aspect a lot of people seem to forget with this scale of project. While we concentrate on all the giant viaducts, tunnels and road crossings, those elements are far outweighed by the number of little structures needed. Every single ditch or stream the route crosses will need a plan to deal with, and most of them will require a way of letting water cross the formation.

 

[GRALISTAIR]

Not forgetting some very, very carefully graded sub base on which the slab track will be laid. Tolerance in low figure mm I should imagine. Plus countless culverts and bridges under that.

So not "crusher-run" then?

 

[Bald Rick]

So not "crusher-run" then?

I don’t know, but it’s possible. whatever it is, it will be well compacted and at fine tolerance.

 

[LNW-GW Joint]

TBM Lydia, boring the 853m logistics tunnel across the Old Oak Common HS2 site, has made it onto the TBM progress map at just 9m on 21 April, since startup on 18 April*.
* although the PR for the launch was on 12 April.

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

 

[Fazaar1889]

https://twitter.com/HS2ltd/status/1651241064810807296?s=20

Our two giant tunnel boring machines, Florence and Cecilia have both passed the 10km (6 miles) point on their 16km journey under the Chilterns

Both Cecilia and Florence are over half way through

 

[Geogregor]

Both Cecilia and Florence are over half way through

And have been for a while, now they crossed 10km mark

 

[LNW-GW Joint]

And have been for a while, now they crossed 10km mark

They were 63% complete at the last update (18 April), and will be 2/3 done by mid-May.

 

[Fazaar1889]

And have been for a while, now they crossed 10km mark

Apologies, I was unaware. I haven't been keeping personal track of each TBM

 

[LNW-GW Joint]

A new update has been posted for the Northolt TBMs for 28 April.
Shushila is at 1269m, substantial progress on the last month, indicating it is making good progress at last (14m/day for the last 10 days).
By contrast Caroline is at 1038m, so has been essentially stopped for the last 10 days.
It does suggest the issue of surface breaches may have been solved.

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: May 3:
More steady progress for the Chiltern TBMs, with Florence and Cecilia now at 10435m and 10340m respectively or about 15m/day since April 18.
It's possible the TBMs were stopped over the bank holiday weekend (and maybe the next two in May too).
HS2 Ltd is ambivalent on the matter; sometimes it says the TBMs work "every day except Christmas Day", and at other times "every day except bank holidays".
They certainly had an extended break over last Christmas/New Year.

Edit: May 4:
Lydia, boring the logistics tunnel at OOC, has advanced from 9m to 15m in the last 13 days.

Edit: May 9:
One of the disconcerting things about the Northolt TBMs is the way progress is posted sometimes well after the event.
So now (May 9) we have an update for May 5 with Shushila and Caroline at 1436m and 1038m respectively.
Shushila is forging ahead at its best rate so far (23m/day for the last week), while Caroline has been stationary for the same week.
So that suggests they have fixed the surface breach problem with modifications to Shushila, with Caroline now getting the same treatment before restarting.
On the map, if I've got the point of origin right, Shushila is now 3/4 of the way down the Herlwyn Avenue gardens, while Caroline is still adjacent to the Ruislip rugby ground area.

 

[LNW-GW Joint]

There's been another surface breach with HS2 tunnelling, this time a sinkhole above the Chiltern tunnels near Amersham:

HS2 contractor confirms ‘sizeable’ sinkhole in Buckinghamshire

Construction firm Align told residents near Amersham the hole is six metres across and five deep

www.theguardian.com

The firm constructing the HS2 high-speed rail line has has confirmed that it is investigating the emergence of a sinkhole close to a Buckinghamshire river on Saturday, which has been identified as “quite sizeable” in correspondence seen by the Guardian.
The sinkhole is close to Shardeloes Lake near Amersham and according to an email from an official from HS2 Ltd’s contractor, Align, sent on Saturday evening to local residents: “It’s quite sizeable – around six meters in diameter and five meters deep. These are approximate measurements.”
The sinkhole is in Bazzards Field, south-west of the lake. It has been fenced off and is near a public right of way.
The email adds: “The landowners have been informed and livestock moved to a safe place.”
HS2 Ltd sources said the area where the sinkhole has emerged is above a section of completed tunnelling, so tunnelling operations are continuing. The sources added that the Environment Agency has been notified and HS2 is engaging with the landowner about the structure.

This screenshot from Google maps shows the area.
The approximate tunnel route for HS2 is shown, and the problematic area is just SW of the River Misbourne crossing.
It's about half-way between the access shafts at Amersham and Little Missenden.
The distances on the measurement line are from the Little Missenden shaft - I think the TBMs will be close to the 1km mark).
There doesn't appear to be any property nearby, just agricultural land and the river valley.

 

[marko2]

There's been another surface breach with HS2 tunnelling, this time a sinkhole above the Chiltern tunnels near Amersham:

HS2 contractor confirms ‘sizeable’ sinkhole in Buckinghamshire

Construction firm Align told residents near Amersham the hole is six metres across and five deep

www.theguardian.com

View attachment 135062

This screenshot from Google maps shows the area.
The approximate tunnel route for HS2 is shown, and the problematic area is just SW of the River Misbourne crossing.
It's about half-way between the access shafts at Amersham and Little Missenden.
The distances on the measurement line are from the Little Missenden shaft - I think the TBMs will be close to the 1km mark).
There doesn't appear to be any property nearby, just agricultural land and the river valley.

From the Guardian Article, we note that NIMBYs are out in force.

“We have been predicting that something like this would happen for the last 10 years,” Jennings said. “We have been giving a consistent message to HS2: ‘Don’t tunnel through chalk, it’s unstable.”

Is chalk inherently less stable to tunnel through? Don't suppose they;d have preferred the railway on a viaduct

"He said he had also contacted Thames Water and asked them to pause supplying water to HS2 in the area until an investigation has been carried out."

Grasping at more straw than a scarecrow with an onanism addiction?

 

[LNW-GW Joint]

Is chalk inherently less stable to tunnel through? Don't suppose they'd have preferred the railway on a viaduct

The Channel Tunnel builders would say not - there's 50km of tunnel through chalk marl, mostly under the sea, to prove it.
There were some difficult ground conditions encountered, at Folkestone on the UK side, and the first 5km under water on the French side.
The Folkstone situation, near the portal, was in close proximity to the SER's Shakespeare Cliff tunnel, which has had stability problems throughout its life.

 

[zwk500]

The Channel Tunnel builders would say not - there's 50km of tunnel through chalk marl, mostly under the sea, to prove it.
There were some difficult ground conditions encountered, at Folkestone on the UK side, and the first 5km under water on the French side.
The Folkstone situation, near the portal, was in close proximity to the SER's Shakespeare Cliff tunnel, which has had stability problems throughout its life.

It depends on the nature of the chalk - plenty of long tunnels through the chalk bands in the South but it can be susceptible to water ingress and faultlines.

 

[LNW-GW Joint]

Updates for all 5 operational TBMs were posted for today May 15 by HS2 Ltd, the first time that has happened.
The Chiltern TBMs, Florence and Cecilia, are at 10555m and 10500m respectively.
The Northolt TBMs, Shushila and Caroline, are at 1383m and 1042.5.
Lydia, the TBM boring the logistics tunnel at OOC, is now at 29.3m.

The Chiltern pair are moving forward at a lower rate than previously but the 12 days included two bank holidays when they might not have worked, as well as having the recent sinkhole problem on the surface.
I can't make head or tail of the Northolt pair: Shushila appears to have gone backwards in the last 10 days, with Caroline edging a few metres forward.
The map graphic with the TBM positions superimposed shows Caroline to be somewhere west of Basildon in Essex...
Lydia has doubled its distance, but 29m in the first month is hardly impressive.

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

 

[TheHSRailFan]

The map graphic with the TBM positions superimposed shows Caroline to be somewhere west of Basildon in Essex...

Southend to Birmingham via London through services sounds interesting...

 

[Bald Rick]

There's been another surface breach with HS2 tunnelling, this time a sinkhole above the Chiltern tunnels near Amersham:

HS2 contractor confirms ‘sizeable’ sinkhole in Buckinghamshire

Construction firm Align told residents near Amersham the hole is six metres across and five deep

www.theguardian.com

View attachment 135062

This screenshot from Google maps shows the area.
The approximate tunnel route for HS2 is shown, and the problematic area is just SW of the River Misbourne crossing.
It's about half-way between the access shafts at Amersham and Little Missenden.
The distances on the measurement line are from the Little Missenden shaft - I think the TBMs will be close to the 1km mark).
There doesn't appear to be any property nearby, just agricultural land and the river valley.

Perhaps not coincidentally, but the ground water levels in the area around the River Misbourne are at their highest level for 2 years, and the amount of rain that fell in the back half of last week was exceptional.

 

[randyrippley]

Sinkhole measuring '20ft wide' opens up above HS2 tunnel

Anti-HS2 campaigners have hit out in response and said tunnelling for the project should stop.

metro.co.uk

"Sinkhole measuring ’20ft wide’ opens up above HS2 tunnel"

 

[LNW-GW Joint]

The Chiltern TBMs are about to pass under the River Misbourne (the second such crossing), so this is presumably the highest risk zone.
They cross the river at a shallow angle so it will take them about 500m of tunnelling (about a month of normal working) to reach higher ground.
I don't know how far below the surface they are, but it will be much lower than the 5m sinkhole.

 

[cuemaster]

I can't make head or tail of the Northolt pair: Shushila appears to have gone backwards in the last 10 days, with Caroline edging a few metres forward.

The positive is Sushila has been moving at around 10m per day since mid April after pausing for a month and there has been no new reports of bubbling at the surface, as far as i am aware. Caroline has now 'paused' for a month so will normal operations resume shortly...?

 

[LNW-GW Joint]

For some reason, HS2 has posted positions today (May 16) for the Chiltern TBMs only one day after the previous post.
Florence is at 10629m, Cecilia is at 10512m.
The Cecilia figure is consistent with yesterday's 10500m, but Florence has advanced an unlikely 74m in one day.
Northolt TBM Caroline is still somewhere near Basildon on the map.
This week's updates don't inspire a lot of confidence in the figures.

== Doublepost prevention - post automatically merged: 23 May 2023 ==


Edit, May 23:
Another update today on all 4 TBMs boring the HS2 tunnels - this now appears to be a coordinated weekly update.
The Chiltern TBMs, Florence and Cecilia, are at 10953m and 10682m, both moving very well despite the sinkhole reported close by.
I think that puts Florence pretty much directly under the River Misbourne.

The Northolt TBMs, Shushila and Caroline, continue to baffle.
Shushila has moved just 7m in the week, still not up to the position reported for May 5.
Caroline has moved 71m and seems to be making progress again at 10m/day.
The Northolt positions are given to 0.01m, and Caroline has been retrieved from its apparent vacation near Basildon and is back in its true position on the map.
No update for Lydia on the OOC logistics tunnel.

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

From the works plan for the West Midlands section, it seems the first TBM for the Bromfield Tunnel (the east portal is close to the M6/M42 junction) is due to start up in June.

 

[cuemaster]

The Northholt TBM's now seem to be tunneling back to expected progress... both at around 15 meters per day now since May 16 to May 26. The chiltern TBM's are still progressing but no new update yet as they move under the river Misbourne, west of Amersham.

 

[LNW-GW Joint]

The Northholt TBM's now seem to be tunneling back to expected progress... both at around 15 meters per day now since May 16 to May 26. The chiltern TBM's are still progressing but no new update yet as they move under the river Misbourne, west of Amersham.

Yes the Northolt pair have put a spurt on and are looking to be in good shape at last.
Shushila looks to be on the point of leaving the Herlwyn Avenue property zone.
Another 500m around Ruislip Gardens and it will be industrial areas and green space above rather than residential property.

Edit, June 2:
Lydia, the TBM boring the logistics tunnel at OOC, has doubled its progress to 66m in the 18 days to June 2.
That represents an average of just 2m a day, and the backup train will still be in the open air at the launch site, after 6 weeks work.

Edit 2:
Later on June 2, HS2 updated the position of TBM Florence in the Chiltern tunnel, to 11155m, so 202m in the last 10 days.
However its mate Cecilia has not moved in that period and is still at 10682m, so maybe under maintenance, or waiting for Florence to reach the far side of the Misbourne crossing.
On the map, Cecilia has apparently been joined by Shushila from the Northolt tunnel.
Does anybody care about the accuracy of the progress map?

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

 

[steveroberts]

First post from me... I'm the nearest house to the tunnel line in Lawn Close, Ruislip and we were expecting Sushila to pass by this last weekend. Assuming she's not actually performed an incredible volte-face and zoomed up to join Cecilia as mentioned above, I'm curious to know exactly where she is. On Thursday evening I became aware for the first time that I could hear her tunnelling, particularly downstairs where the parquet floor on concrete is providing a bit of a sounding board. But since Friday afternoon, everything has been quiet. So either she has been and gone almost silently or she's stopped again. We have HS2 surveyors measuring on the tunnel line every morning but I've not been able to speak to any of them.

I did tweet HS2 this morning about the position of Sushila on their works map, but haven't had any response as of yet.

Edit: They've just updated it and the position they have her in is almost directly behind my house. No idea how geographically or temporally accurate that is though.