HS2 TBM Progress

[LNW-GW Joint]

Hi Steve, it's good to have some resident input, and welcome to the forum.
The Northolt TBM positions on the HS2 map (if you click on the TBM icons) are from May 26, so 10 days old at the moment.
But Shushila does look to be alongside Lawn Close.
I've presumed the TBM drives are essentially under the Chiltern railway boundary, but that might not be right.
Caroline will be following 25m or so the east of Shushila I think, so may pass closer to you in the near future.
Once they've passed by, smaller cross-tunnels need to be built connecting the rail tunnels every 500m or so, and one of those might be near you.

 

[GRALISTAIR]

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.

Welcome to the forum. Your first post. Looking forward to more from you. Thanks

 

[cuemaster]

Does anybody care about the accuracy of the progress map?

In the spirit of carrying on, the chiltern tunnels tbm progress website has been updated today. Florence is now past 70% complete at 11401m , an impressive 61.5m per day since 2nd June. Cecilia now is showing 11001m which is approx 23m per day since 23rd May which was the last reliable update and is quite close to passing under the river Missenden, unlike Florence TBM which is now only several hundred meters from Little Missenden ventilation shaft.

 

[LNW-GW Joint]

In the spirit of carrying on, the chiltern tunnels tbm progress website has been updated today. Florence is now past 70% complete at 11401m , an impressive 61.5m per day since 2nd June. Cecilia now is showing 11001m which is approx 23m per day since 23rd May which was the last reliable update and is quite close to passing under the river Missenden, unlike Florence TBM which is now only several hundred meters from Little Missenden ventilation shaft.

This is impressive.
Florence must now be at a point near the A413 dual carriageway*, and away from the river zone.
The logistics must be increasingly difficult with segments having to come 11km through the tunnel from the factory site at the south portal.

*may be about 200m short of the A413, if the TBM location on the map is correct, with Cecilia still a little south/west of the river Misbourne.

 

[alf]

Since the cross tunnels have been mentioned at post 152
I have a question about them.

Are special full size segments produced & transported down the new tunnel when it is their turn to be inserted & do they have preformed holes for the start of the ninety degree cross tunnel?

Or are the holes drilled out of an ordinary segment once it is in place & how is the cross passage dug? manually, with a special tunnelling machine or some other way?
Thanks!

 

[Bald Rick]

Since the cross tunnels have been mentioned at post 152
I have a question about them.

Are special full size segments produced & transported down the new tunnel when it is their turn to be inserted & do they have preformed holes for the start of the ninety degree cross tunnel?

Or are the holes drilled out of an ordinary segment once it is in place & how is the cross passage dug? manually, with a special tunnelling machine or some other way?
Thanks!

Typically, the previously installed segments at the location of the cross passages are removed, and excavation by hand (or with a small road header). The segments to be removed are, of course, designed to be removed.

I don’t know if this is the case for these tunnels, or whether some other method is being deployed. The Chiltern tunnels have seen much innovation in tunnelling method.

 

[Snow1964]

There is a newly published works in your area update, that gives details of construction of the ventilation shafts and adits. Gives details for 3 months and outline for next 12 months

This is the one for Brent and Ealing, it appears the safe stop date for works in Kilburn is Spring 2024 (following announcement of Euston pause)

https://assets.hs2.org.uk/wp-content/uploads/2023/06/Summer-2023-Construction-look-ahead-Brent-and-Ealing.pdf

 

[chris2]

Confirmation of the Birmingham TBM launches, first one starting this month (mid June), second to follow in early 2024, according to

https://www.hs2.org.uk/work-items/tunnelling-works-set-to-begin-in-north-warwickshire/

 

[LNW-GW Joint]

Are special full size segments produced & transported down the new tunnel when it is their turn to be inserted & do they have preformed holes for the start of the ninety degree cross tunnel?
Or are the holes drilled out of an ordinary segment once it is in place & how is the cross passage dug? manually, with a special tunnelling machine or some other way?
Thanks!

As I understand it, there are no segments in the cross-passages, just sprayed concrete.
The profile of the cross-passages will be much smaller than the rail tunnels, and I guess they might be 20m long (rail tunnel diameter is about 10m).

PS Lydia, boring the logistics tunnel at OOC, has reached 90m* today, still not quite fully inserted in the tunnel but doing about 5m/day now.

* corrected to 80m next day!

 

[stuving]

As I understand it, there are no segments in the cross-passages, just sprayed concrete.
The profile of the cross-passages will be much smaller than the rail tunnels, and I guess they might be 20m long (rail tunnel diameter is about 10m).

According to HS2 and Align, cross passages are 15-20 m long, though obviously that depends on the bore spacing. The diameter is roughly half that of the main bores (which are 8.8 m internally), though I can't find a figure for it. The flat floor is level with the "platforms" alongside the tracks, so the passages are centred well below the main bores.

The building of a cross passage starts with cutting a big hole in each tunnel wall. To maintain the tunnel's strength there are special lining segments for this, with extra reinforcement around the intended hole. Somehow, they have to get fed into the stream of segments at just the right place. Something similar happens for the vertical shafts, but they are much bigger. Steel frames are also used to bind the tunnels and shafts together. (HS2 describe alternative ways of doing this too; it's not clear which is use in the Chiltern tunnels.)

 

[LNW-GW Joint]

The rescheduling of the work between Old Oak Common and Euston has been clarified in an HS2 presentation, and the delay to tunnel construction is less than 2 years.

https://assets.hs2.org.uk/wp-content/uploads/2023/05/2205-Presentation-Euston-Tunnel-Update-May-2023.pdf

Completion of the Atlas Road logistics tunnel (being bored by TBM Lydia): Winter 2023 [I think this means by the end of 2023]
Euston tunnel TBMs delivered: from Summer 2024 [some 6 months later than plan]
Adelaide Road and Canterbury Works vent shaft brought to a safe pause: by April 2024
TBMs placed ready to bore at Old Oak Common: from Spring 2025
Construction of the Euston tunnel: from Summer 2025

So while the dates have slipped to the right, the TBMs should start up about 18 months later than originally planned.
Presumably these dates are compatible with completion of the station at OOC ready for its planned opening for initial Birmingham services.
The tunnels should be completed early in 2027.

 

[GRALISTAIR]

Well I am relieved to say the least. I think Eastern Leg will get built eventually too though possibly not in my lifetime.

 

[Ethan1852]

Since the cross tunnels have been mentioned at post 152
I have a question about them.

Are special full size segments produced & transported down the new tunnel when it is their turn to be inserted & do they have preformed holes for the start of the ninety degree cross tunnel?

Or are the holes drilled out of an ordinary segment once it is in place & how is the cross passage dug? manually, with a special tunnelling machine or some other way?
Thanks!

Here is a short video from HS2 about how cross passages are constructed.

 

[TheoBald]

Am I missing something? If the cross tunnels are 500m apart, passengers will never be more than 250m from the nearest - half the distance claimed in the video.

 

[Chonner]

Am I missing something? If the cross tunnels are 500m apart, passengers will never be more than 250m from the nearest - half the distance claimed in the video.

The thing (fire, blockage or other hazard) you are trying to escape from could block your route in one direction, necessitating you to walk to one further away in the other direction.

 

[absolutelymilk]

Sushila and Caroline were updated on 12 June, and are now at 1,741m and 1,371m respectively

 

[steveroberts]

Sushila and Caroline were updated on 12 June, and are now at 1,741m and 1,371m respectively

Well, considering how close Sushila was to my house, I'm amazed at how quiet she was. I was aware of being able to hear her for maybe one day, but it was a very faint rumble. Caroline will be closer when she passes, so it will be interesting to see if there's any difference.

 

[Fazaar1889]

TBM digging Bromfors tunnel is called Mary Ann

https://twitter.com/HS2ltd/status/1669030812375818242?t=AiNg24EOR0LW8JCmUiRiXQ&s=19

Today we unveil a huge tunnel boring machine ready to dig our Bromford Tunnel between Water Orton in North #Warwickshire and Washwood Heath in #Birmingham

 

[LNW-GW Joint]

I see the spoil from the Bromford tunnels will be reused in the Delta Junction area rather than be transported to landfill like that from the London tunnels.
Do we know how the tunnel segments reach the portal?
I believe they are manufactured at a concrete plant in Avonmouth, and the TBM portal site is close to the WCML.
Going back a bit, I don't know how the segments for the completed Long Itchington tunnels (same contractor as for Bromford, BBV) reached the site, but it was remote from existing rail routes.

 

[swt_passenger]

I see the spoil from the Bromford tunnels will be reused in the Delta Junction area rather than be transported to landfill like that from the London tunnels.
Do we know how the tunnel segments reach the portal?
I believe they are manufactured at a concrete plant in Avonmouth, and the TBM portal site is close to the WCML.
Going back a bit, I don't know how the segments for the completed Long Itchington tunnels (same contractor as for Bromford, BBV) reached the site, but it was remote from existing rail routes.

There are a number of bored tunnel segment plants around the country, some remote such as Isle of Grain, Hartlepool and Avonmouth, and some at more adjacent sites eg Denham, for the Chiltern tunnels and Kingsbury in Warwickshire. I think the latter will be nearest Bromford. It would be interesting to see a map showing all the locations across the country, and which sites they feed.

There are also the different types of concrete precast units used in the green tunnels which are cut and cover. I think they come from Stanton in Derbyshire.

 

[david_g]

Going back a bit, I don't know how the segments for the completed Long Itchington tunnels (same contractor as for Bromford, BBV) reached the site, but it was remote from existing rail routes.

Lorries. Lots of them. There would be a couple parked up in lay-by on the Southam bypass overnight pretty much every time I drove past.

 

[LNW-GW Joint]

Lorries. Lots of them. There would be a couple parked up in lay-by on the Southam bypass overnight pretty much every time I drove past.

Presumably the same setup for Bromford then.
It would have been good to see heavy segment trains climbing the Lickey.

 

[GRALISTAIR]

Presumably the same setup for Bromford then.
It would have been good to see heavy segment trains climbing the Lickey.

Absolutely!

 

[LNW-GW Joint]

Well, considering how close Sushila was to my house, I'm amazed at how quiet she was. I was aware of being able to hear her for maybe one day, but it was a very faint rumble. Caroline will be closer when she passes, so it will be interesting to see if there's any difference.

If I've got the portal location correct on Google Maps, Shushila was adjacent to 27 Lawn Close on June 12, with Caroline adjacent to 120 Herlwyn Avenue 370m back.
They are both moving at about 10m/day, so should be 60m-odd beyond those points now.


EDIT:

An update today (June 19) for all four main line TBMs.

In the Chiltern tunnels, Florence/Cecilia are at 11557m/11201m respectively, advancing at 12/15m per day.
Florence must now be very close to the Little Missenden vent shaft.

In the Northolt West tunnel, Shushila/Caroline are at 1810m/1420m respectively, advancing at 10/7m per day.
Shushila must now be adjacent to the property in Almond Close.

No update for Lydia on the logistics tunnel at OOC, and the start up of new TBM Mary Ann at Bromford is awaited.

 

[kevin_roche]

There was a statement on HS2 in the commons yesterday by Huw Merriman, Minister of State (Department for Transport).

https://questions-statements.parliament.uk/written-statements/detail/2023-06-19/hcws858

It mentions the tunnelling progress in amongst lost of other things...

Delivery

On Phase One, delivery continues to build momentum with around 350 active construction sites between the West Midlands and London. Six years after beginning work, all the early works contractors have now left sites having prepared them for the main work civils contractors who are entering peak construction effort this year.

Tunnel drives are making good progress across all 3 sites. In March 2023, the  TBM  named Dorothy completed its work under Long Itchington Wood in Warwickshire, completing its second one-mile drive and marking the first complete twin-bore tunnel across the project. In the Chilterns, the TBMs called Florence and Cecilia have successfully reached Amersham Vent Shaft, which represents the halfway point of their 10-mile drive. Sushila and Caroline, the 2 TBMs used to create the first section of tunnel that will make up the 8.4-mile Northolt Tunnels between West Ruislip and Old Oak Common station, are also making progress.

Overall, 5 of the 10 TBMs boring the tunnels for the route have launched, 2 of the 12  TBM  journeys are now complete and approximately 14.5 miles have been dug.

 

[LNW-GW Joint]

Another rapid update on the Chiltern TBMs for June 22, only 3 days since the last.
Florence and Cecilia are at 11771m and 11431m respectively, meaning a rather unlikely 70m/day progress for both.
I suspect Florence has now reached the Little Missenden vent shaft, so may pause there for a bit.
Cecilia is 340m behind, so maybe 3 weeks or so for it to get to the same place.
Percentage-wise, Florence has now dug 73.5% of its target tunnel.
At recent rates, the northern portal might be reached by the end of January 2024, several months early.

In your area map

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

 

[cuemaster]

Another rapid update on the Chiltern TBMs for June 22, only 3 days since the last.
Florence and Cecilia are at 11771m and 11431m respectively, meaning a rather unlikely 70m/day progress for both.
I suspect Florence has now reached the Little Missenden vent shaft, so may pause there for a bit.
Cecilia is 340m behind, so maybe 3 weeks or so for it to get to the same place.
Percentage-wise, Florence has now dug 73.5% of its target tunnel.
At recent rates, the northern portal might be reached by the end of January 2024, several months early.

In your area map

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

This is great progress since the both TBM's had acheived 50% completion at the beginning of January. Hopefully they'll be no significant events to react to and so complete an early completion... time is money as they say.

 

[LNW-GW Joint]

A rapid update on the Northolt TBMs today.
Shushila and Caroline are now (June 26) at 1838m and 1473m respectively.
That's 28m and 53m in the last week - not impressive, compared to the Chiltern machines which can do 20m+ a day.

 

[Bald Rick]

A rapid update on the Northolt TBMs today.
Shushila and Caroline are now (June 26) at 1838m and 1473m respectively.
That's 28m and 53m in the last week - not impressive, compared to the Chiltern machines which can do 20m+ a day.

Very different geology, and also different consequences if it goes wrong, especially given what is above them.

 

[Geogregor]

Good report about state of tunneling:

Future of Tunnelling | Four High Speed 2 twin bores progressing well despite challenges | New Civil Engineer

High Speed 2 (HS2) tunnelling activity between London and the West Midlands is continuing despite the government’s decision to halt work on the project’s

www.newcivilengineer.com