HS2 TBM Progress

[Mojo]

A letter sent to local residents yesterday has been attached and states that Sushila has been paused.

Whilst we are undertaking the local ground investigations and developing revised tunnelling techniques, we have paused TBM Sushila in the recreation area. This new technique is currently being trialled by our second TBM Caroline within the recreation area to provide reassurance prior to recommencing tunnelling with TBM Sushila.


As TBM Caroline undertakes these trials, we will be monitoring ground conditions to inform the next steps. It is possible that air will continue to bubble at the surface over the next few days.


TBM Sushila will not restart until we have concluded these trials and we are confident that the grout issues that occurred in the recreation ground will not reoccur in the location of your property.

 

[cuemaster]

Makes you wonder how deep the TBM's are or whether there are existing bore/trial holes which are to blame or something else. Its obviously garnered attention from a vocal few in certain areas of social media.. Time will tell if it amounts to anything.

 

[LNW-GW Joint]

From the distances previously posted, Shushila should be about half way down the Herlwyn Avenue stretch, while Caroline is about 300m behind and about to clear the rugby recreation area.
Presumably the TBM trace is offset somewhat to the east of the Chiltern route and they are due to pass below Herlwyn Ave property (gardens?) on this stretch.
This doesn't quite tally with the letter to residents, which suggests both TBMs are still under the recreation area.
No doubt things will clarify.

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[Andrew*Debbie]

nobody is going to go public with what the critical path actually ... With high voltage grid connections being quoted as 5 years my guess is this will allow some slippage elsewhere in the project, like tunnelling.

I hope that the TBM grid connections will be reused to provide some of the power needed to operate HS2.

 

[zwk500]

I hope that the TBM grid connections will be reused to provide some of the power needed to operate HS2.

Do TBM launch sites really need their own substations on the main power grid rather than coming off the local supply? I'm fairly sure the traction power for HS2 is all coming from the Feeder station at Steeple Claydon where HS2 crosses EWR and the Infrastructure Maintenance Depot is.

 

[Elecman]

Do TBM launch sites really need their own substations on the main power grid rather than coming off the local supply? I'm fairly sure the traction power for HS2 is all coming from the Feeder station at Steeple Claydon where HS2 crosses EWR and the Infrastructure Maintenance Depot is.

thats the plan

 

[stuving]

Do TBM launch sites really need their own substations on the main power grid rather than coming off the local supply? I'm fairly sure the traction power for HS2 is all coming from the Feeder station at Steeple Claydon where HS2 crosses EWR and the Infrastructure Maintenance Depot is.

The TBM power supply at Ruislip is provided by a cable under the streets from a UKPN (so DNO not national grid) substation at Rayners Lane. Afterwards it, via the new substation at the Ruislip end, will not be reused for traction power. Presumably it will be mainly for tunnel ventilation and lighting, as well as other auxiliary circuits. It might be used by UKPN as part of their own distribution network, though the wording of HS2's description suggests it will not be.

Details from HS2 include this:

A high capacity 33 kilovolt (kV) 20 mega volt amp (MVA) cable power supply is needed at West Ruislip for the tunnel boring machines that will run between Ruislip and Old Oak Common to create the twin-bore Northolt tunnels.

Once the tunnelling is complete, the power supply will be used to power operational equipment within the tunnels.

UK Power Networks have undertaken the work to lay the cable. The cable will remain the property of UK Power Networks and they will maintain it.

 

[Bald Rick]

I hope that the TBM grid connections will be reused to provide some of the power needed to operate HS2.

The TBMs use rather less power than HS2 will need !

 

[Elecman]

20MVA is a pretty hefty supply in its own right. The Point of Connnection would be the outgoing connection on the UKPN switchgear as that equipment would also remain UKPN property as well as the supply cable.

 

[Andrew*Debbie]

The TBMs use rather less power than HS2 will need !

Yes, but the TBM grid connections are substantial.

Searching quickly found some answers.

The TBM grid connection at West Ruislip is 33kV, 20MVA. That is a medium voltage connection. -- Two similar 33kV 3-phase cables run under the middle of the small rural street I live on.

20MVA is approximatly 20MW, enough to power ~12,000 homes.

In the case of West Ruislip, the connection will be reused to provide power to equiptment in the tunnels. I assume this is ventillation, signaling, lighting and well everything except HV traction power.

20. Will the cable be used after the tunnel boring machines have finished? Yes, once the tunnelling is completed, then the power supply will then be used to provide power to equipment within the tunnels between West Ruislip and Old Oak Common when the HS2 trains are running

Somewhere upthread, Zwk500 said "I'm fairly sure the traction power for HS2 is all coming from the Feeder station at Steeple Claydon where HS2 crosses EWR and the Infrastructure Maintenance Depot is."

This is incorrect. There will be about 50 grid substations for HV traction between London and Crewe. It is likely Steeple Claydon will be one of the 50 locations.

Approximately 50 traction sub-stations will be built alongside the line between London and Crewe in order to deliver power from the National Grid to the trains. The contractor will also deliver a dedicated HV non-traction power network that will provide power to stations, shafts, portals, depots and railway systems along the route.

Sources:

https://s3-eu-west-1.amazonaws.com/commonplace-customer-files/hs2inhillingdon/TBM%20QandA%20V2%20290719.pdf

Tunnel boring machine (TBM) power supply route - HS2

www.hs2.org.uk

HS2 shortlists bidders for high voltage power supply systems

HS2 today shortlisted bidders for its high voltage (HV) power supply systems. The winning organisations will go on to deliver electrical systems covering 280km of the UK's new high speed rail link and enable millions of people to enjoy low carbon journeys between London, Birmingham and the...

mediacentre.hs2.org.uk

 

[dosxuk]

20MVA is approximatly 20MW, enough to power ~12,000 homes.

Either my calculations are way out, or yours are? I make it about 1000 homes.
(20MVA = 20000kVA. Home supplies vary between 60A and 100A = approx 13.8kVA to 25kVA - so we'll take the average: 19.4kVA. 20000kVA / 19.4kVA = 1030).

 

[Bald Rick]

Yes, but the TBM grid connections are substantial.

Searching quickly found some answers.

The TBM grid connection at West Ruislip is 33kV, 20MVA. That is a medium voltage connection. -- Two similar 33kV 3-phase cables run under the middle of the small rural street I live on.

20MVA is approximatly 20MW, enough to power ~12,000 homes.

In the case of West Ruislip, the connection will be reused to provide power to equiptment in the tunnels. I assume this is ventillation, signaling, lighting and well everything except HV traction power.






Somewhere upthread, Zwk500 said "I'm fairly sure the traction power for HS2 is all coming from the Feeder station at Steeple Claydon where HS2 crosses EWR and the Infrastructure Maintenance Depot is."

This is incorrect. There will be about 50 grid substations for HV traction between London and Crewe. It is likely Steeple Claydon will be one of the 50 locations.





Sources:

https://s3-eu-west-1.amazonaws.com/commonplace-customer-files/hs2inhillingdon/TBM%20QandA%20V2%20290719.pdf

Tunnel boring machine (TBM) power supply route - HS2

www.hs2.org.uk

HS2 shortlists bidders for high voltage power supply systems

HS2 today shortlisted bidders for its high voltage (HV) power supply systems. The winning organisations will go on to deliver electrical systems covering 280km of the UK's new high speed rail link and enable millions of people to enjoy low carbon journeys between London, Birmingham and the...

mediacentre.hs2.org.uk

This is confusing Grid Connections and substations.

The Grid Connections are typically at 80MVA. These will be roughly every 50km along the route. Claydon is one. There’s another at Burton Green.

The 50 substations are part of the distribution system.

 

[bib]

Either my calculations are way out, or yours are? I make it about 1000 homes.
(20MVA = 20000kVA. Home supplies vary between 60A and 100A = approx 13.8kVA to 25kVA - so we'll take the average: 19.4kVA. 20000kVA / 19.4kVA = 1030).

Depends if you are talking averages or peak consumption.

Very roughly speaking, I think a typical UK home uses approx 10kWh per day, so you could approximate that as a constant 0.4kW. So a constant 20MW over 24hrs would be roughly the same as 50,000 homes over 24hrs.
I presume the 60-100A is the peak supply limit, which is equivalent to 14-24kW, for the rare short-lived occasion when you are running 3 kettles, a microwave, tumbledryer and electric oven simultaneously.
Although I guess TBM is unlikely to be running near 20MW constantly for 24hrs, no idea what the actual consumption would be.

 

[zwk500]

Somewhere upthread, Zwk500 said "I'm fairly sure the traction power for HS2 is all coming from the Feeder station at Steeple Claydon where HS2 crosses EWR and the Infrastructure Maintenance Depot is."

This is incorrect. There will be about 50 grid substations for HV traction between London and Crewe. It is likely Steeple Claydon will be one of the 50 locations.

I refer you to this document: https://hs2ltd.files.wordpress.com/2011/05/powering-hs2.pdf

At four points along the London to West Midlands route, the wires would be connected to the National Grid to obtain a power supply. Typically, these would be at locations close to an existing pylon route to minimise disruption and additional equipment.
[...]
Every 6 or 7 miles (10km) intermediate ‘Autotransformer stations’ would also be required to strengthen the power supply.

So I was incorrect that there was only 1 feeder station, but the 50 substations are intermediate points between the Feeder station and the trains, not grid supply connections themselves.

 

[Andrew*Debbie]

Either my calculations are way out, or yours are? I make it about 1000 homes.
(20MVA = 20000kVA. Home supplies vary between 60A and 100A = approx 13.8kVA to 25kVA - so we'll take the average: 19.4kVA. 20000kVA / 19.4kVA = 1030).

The calculations are based on "after diversity maximum demand."

House rarely pull anyting close the the 80A or 100A allowed by the main fuse. All the houses in a region don't reach maximum demand at the same time.

The distribution network counts on us eating breakfast, doing the laundry, taking showers at different times. If all the houses on one substation demanded 80A at the same time the power would trip off.

 

[dosxuk]

The calculations are based on "after diversity maximum demand."

House rarely pull anyting close the the 80A or 100A allowed by the main fuse. All the houses in a region don't reach maximum demand at the same time.

The distribution network counts on us eating breakfast, doing the laundry, taking showers at different times. If all the houses on one substation demanded 80A at the same time the power would trip off.

Even so, at 12,000 homes, that only allows for a maximum base load per-house of about 7A, which seems exceptionally low. With 12,000 homes connected, even if every house on that circuit demanded 8A the power would trip off.

 

[GRALISTAIR]

Even so, at 12,000 homes, that only allows for a maximum base load per-house of about 7A, which seems exceptionally low. With 12,000 homes connected, even if every house on that circuit demanded 8A the power would trip off.

Especially if in the future we are all going to be re-charging electric cars.

 

[LNW-GW Joint]

An odd update today for Chiltern TBM Cecilia (for 4 April), posted as 9836m.
There is no update for Florence, normally the lead TBM, which is still showing 9709m for 28 March.
Cecilia's progress is 336m in 6 days which is twice the best rate to date, which seems unlikely.
I'm not sure this update is correct - we shall see. Maybe I have caught them mid-update...

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[Elecman]

This is confusing Grid Connections and substations.

The Grid Connections are typically at 80MVA. These will be roughly every 50km along the route. Claydon is one. There’s another at Burton Green.

The 50 substations are part of the distribution system.

Correct

 

[LNW-GW Joint]

Another update for the Chiltern TBMs for Apr 11: Florence and Cecilia are at 9979m and 9956m respectively, both knocking on the door of 10km and 62% of the job done.
Cecilia has also passed the target average of 15m a day (it started 50 days behind Florence).
The missing data for Florence last week is not explained - seemingly just not posted for our delectation.
The next (fourth) vent shaft is at Little Missenden at 11.6km, so that's about 3 months away.
Both TBMs must be within 200m or so west of Amersham Cricket Club's ground.

 

[pokemonsuper9]

Video from HS2 of the Launch of a new TBM in London, for a 853m long logistics tunnel (goods conveyors)

Text from video:

This huge tunnelling machine is building an 853m-long logistics tunnel for HS2.
The tunnel will be used to move materials between our London sites removing thousands of lorry journeys from local roads.
The TBM, named "Lydia" weighs around 1,000 tonnes and is 150m in length.
This machine was previously used to dig the Elizabeth line tunnels.
It has been refurbished, reassembled and renamed for use on HS2.
Once complete, the tunnel will connect to our west London Conveyor network which will remove over one million lorry journeys for HS2's construction.

 

[LNW-GW Joint]

This is pretty firm evidence that despite the Euston station construction being paused, the intention is to build the Euston tunnels in parallel with building the HS2 station at OOC.
Otherwise there would be no point in building this logistics tunnel to service the Euston TBMs.
From what I can make out, Lydia should finish its short drive before year-end, so that the Euston TBMs can be assembled at the far end for launch early in 2024.
Repurposing a Crossrail TBM is useful sign of practical thinking by the HS2 team.
Spoil removal/segment supply for Lydia, and for the Euston TBMs when they start, will all be via the Willesden Euroterminal by rail.

== Doublepost prevention - post automatically merged: 13 Apr 2023 ==

There appears to be some complication with spoil storage for the Northolt Tunnels at West Ruislip.
A conveyor was being built to move the spoil from the tunnel portal to storage areas further out, but completion has slipped from 31 March to 31 May.
This means more lorry movements until the conveyor is completed.
I'm not sure where the spoil is intended to go eventually, it doesn't appear to be being transported to remote sites by train as at Old Oak Common.
This is the info for residents:

https://assets.hs2.org.uk/wp-content/uploads/2023/03/280323-TBM-material-storage.pdf

In December 2022 we let you know that we would be moving Tunnel Boring Machine (TBM) material from 9 January to 31 March 2023 via lorries to storage areas within our site. However, we now need additional time to store the earth excavated from the tunnels, which will extend our completion date to the end of May 2023. We are building a conveyor that will transport earth from the tunnels to the Southern Sustainable Placement Area (SSPA) and reduce the use of lorries. This will be operational from June 2023. The construction of the conveyor is ongoing but has been delayed due to:
 adverse weather;
 approval of rail possession (when a section of track is required for maintenance and trains cannot run) and;
 planning road closures so their impact is minimised on the area’s road network

 

[Bald Rick]

Repurposing a Crossrail TBM is useful sign of practical thinking by the HS2 team.

Herrenknecht often have buy back clauses for TBMs, so this isn’t that surprising.

 

[cuemaster]

Herrenknecht often have buy back clauses for TBMs, so this isn’t that surprising.

Looking further ahead, there's more tunnelling to do south of Manchester on current plans, so if they could do the same thing, would help wih costs i'd imagine.

 

[LNW-GW Joint]

Looking further ahead, there's more tunnelling to do south of Manchester on current plans, so if they could do the same thing, would help wih costs i'd imagine.

They are long tunnels though, 12km or so, and will likely need new TBMs.
Before then, there are 2 short tunnels on Phase 2a at Whitmore and Madeley (700m each), which might be able to use recycled TBMs.
Until recently, these tunnels were due to be bored quite soon, but with the Phase 2a delay some of the Phase 1 TBMs are likely to finish before the new tunnels need boring.
So there might be several spare by then. Dorothy might have another job to do!
There's also the tunnel under Crewe station as part of the Manchester leg.

 

[InOban]

They may need modification to deal with different Geology.

 

[cuemaster]

Certainly the news regarding ‘Lydia’ tbm is encouraging. One mustn’t forget the unprecedented events since 2020 and subsequent economic headwinds.

Is there any news when the northbound tbm’s will launch from OOC?

 

[LNW-GW Joint]

Is there any news when the northbound tbm’s will launch from OOC?

Somewhere on the Old Oak section of the HS2 site it says Northolt East's TBMs will start in "summer 2023" and taking a year, but that was in a document dated Oct 2022.
Elsewhere it says they will launch "by the end of the year".
It also says the 360m between the Victoria Road access shaft and OOC station will be constructed without a TBM, using the Austrian tunnelling method.

== Doublepost prevention - post automatically merged: 17 Apr 2023 ==


EDIT Mon Apr 17:
There's an important update today (April 17) for the Northolt TBMs.
Shushila is at 1109m, and Caroline at 1034m, advances of 2m and 67m since March 16.
These are concerning figures.
Shushila has essentially been stopped since soon after grout from the TBM drive reached the surface in the Ruislip Rugby Club fields on February 19 (see posts #36 and #91).
The HS2 recovery plan was to use Caroline to test an improved boring procedure before applying the fix to Shushila, which would be paused in the meantime.
We can see now that Shushila is still paused some 8 weeks after the event.
Caroline has advanced to be almost level with Shushila, but the situation looks unresolved.
The TBMs were already behind schedule in their 8km drive, and the delay will now be accumulating.

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[cuemaster]

HS2 updated their website this morning - last update was 16th March...so Caroline TBM has now moved a further 150m or so, still 75m behind Sushila TBM (1109m) which remains paused as stated in #91.

I haven't heard any news about bubbling pools recently so maybe they're making progress on resolving whatever was causing it.

 

[LNW-GW Joint]

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.