HS2 construction updates

[swt_passenger]

Theres a vent shaft already under construction in an open space alongside Greenford Mail Centre. Google maps has a link to photos. There doesn't seem to be a vent shaft at Kilburn Delivery Office anymore, it’s been relocated about 300 yards to the west alongside Canterbury Terrace, it’s also well into its construction phase.

It looks very much to me as though worries about the two Royal Mail facilities are history.

 

[Elecman]

Theres a vent shaft already under construction in an open space alongside Greenford Mail Centre. Google maps has a link to photos. There doesn't seem to be a vent shaft at Kilburn Delivery Office anymore, it’s been relocated about 300 yards to the west alongside Canterbury Terrace, it’s also well into its construction phase.

It looks very much to me as though worries about the two Royal Mail facilities are history.

Where the old Kilburn TSC was

 

[city dweller]

Long Itchington TBM

 

[swt_passenger]

Where the old Kilburn TSC was

Thanks. Does that mean there was already a large enough open space before work started?

 

[Yindee8191]

Long Itchington TBM

View attachment 118165

Brilliant! What a milestone - first completed tunnel bore.

 

[Bald Rick]

Long Itchington TBM

View attachment 118165

looks like it’s a millimetre off alignment

 

[edwin_m]

looks like it’s a millimetre off alignment

Better back up and try again then.

 

[LNW-GW Joint]

It almost looks like an abstract painting.
Where are the cheering crew and and admiring media and politicians?

Today's "HS2 is bad for us" story is from a Tory politician fearful of the whole project bringing the next government (the one just being formed) down with cost overruns...

 

[Yindee8191]

It almost looks like an abstract painting.
Where are the cheering crew and and admiring media and politicians?

Today's "HS2 is bad for us" story is from a Tory politician fearful of the whole project bringing the next government (the one just being formed) down with cost overruns...

I shouldn’t think they’ll need HS2’s help…

On a topical (ish) note, surely cancelling HS2 would be madness now? Most of the money for phase one is committed and the environmental damage is largely done.

 

[Mikey C]

I shouldn’t think they’ll need HS2’s help…

On a topical (ish) note, surely cancelling HS2 would be madness now? Most of the money for phase one is committed and the environmental damage is largely done.

It would be crazy to do the expensive and complicated section, and leave the easier bit!

In reality, cancelling any more of it would look awful for their "levelling up" credibility, when trying to defend newly won Northern seats (e.g. Stoke where the leader debate was tonight)

 

[city dweller]

It almost looks like an abstract painting.
Where are the cheering crew and and admiring media and politicians?

Today's "HS2 is bad for us" story is from a Tory politician fearful of the whole project bringing the next government (the one just being formed) down with cost overruns...

DFT have put out a press release

History made as Dorothy – HS2’s state-of-the-art tunnel boring machine – completes the project’s first tunnel after 8 months underground

Historic breakthrough on London to Birmingham route.

www.gov.uk

 

[LNW-GW Joint]

And there's a picture from a different angle on the HS2 site:

HS2 celebrates historic first tunnelling breakthrough

Massive Tunnel Boring Machine (TBM) in Warwickshire becomes first on the HS2 project to complete its full journey underground The first bore of the one-mile tunnel under Long Itchington Wood has been dug in seven months

mediacentre.hs2.org.uk

Over the next four months, the cutterhead and front section of the TBM will be dismantled and transferred back to the north portal, while the bulk of the machine will be brought back through the tunnel. It will be reassembled, ready to launch for the second bore of the tunnel.

 

[ABB125]

It's been a very low key event. There haven't even been any internal PR releases within the contractor...

 

[camflyer]

It would be crazy to do the expensive and complicated section, and leave the easier bit!

In reality, cancelling any more of it would look awful for their "levelling up" credibility, when trying to defend newly won Northern seats (e.g. Stoke where the leader debate was tonight)

Cancelling would surely cost more than it would to finish Phase 1 what with the compensation payments to businesses and the cost of undoing the landworks so far

The fact that 50% of people in surveys still want it cancelled just shows what a bad job HS2 and the government have done in selling the scheme to the public. I'm sure that a lot of people calling for it to be totally cancelled aren't aware of how much work has already been done. Compare this to Crossrail which despite mounting costs and delays still maintained good public engagement.

 

[LNW-GW Joint]

As I read it, the politician wasn't campaigning for cancellation.
The gist was that the government would be unable to contain a cost overrun which would then sink other government schemes.
ie they are hostage to HS2 and its project management (with Crossrail and other troublesome rail project history as examples).

The channel tunnel cost 2-3 times the budget, but that only hit the shareholders (mainly the contractors and individual investors, the majority of whom were French).
GW and NW electrification also cost 2-3 times the budget, but NR (ie the government) took the hit, and we are still feeling the consequences.
HS2 is now in that dangerous period where the programme managers are reliant on the contractors delivering close to the budget (with inflation raging).

 

[snowball]

The breakthrough has just been on the lunchtime BBC TV news, near the end.

 

[city dweller]

Once you have seen the first minute you get the idea there isn't anything much different in the other four minutes.

 

[snowball]

The breakthrough has just been on the lunchtime BBC TV news, near the end.

I just watched it again on Iplayer. There was a bizarre claim that it "connected the first 64 miles of tunnel"??!!

 

[kevin_roche]

I just watched it again on Iplayer. There was a bizarre claim that it "connected the first 64 miles of tunnel"??!!

Journalists? Eh?

In the Government Announcement it says:

this is the first of 64 miles of intricate tunnels set to make up Europe’s largest infrastructure project, marking a huge step towards quicker, greener and more reliable transport   

 

[LNW-GW Joint]

The breakthrough of the Long Itchington west bore was on July 22, so 232 days for the 1480m or an average of 6.38m/day.
Both Chiltern TBMs have now gone past the 5km mark (out of 16km, or about 32% complete).
Their current rate is over 20m/day, close to the best achieved so far.

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

 

[Winthorpe]

HS2 celebrates historic first tunnelling breakthrough

Massive Tunnel Boring Machine (TBM) in Warwickshire becomes first on the HS2 project to complete its full journey underground The first bore of the one-mile tunnel under Long Itchington Wood has been dug in seven months

mediacentre.hs2.org.uk

Over the next four months, the cutterhead and front section of the TBM will be dismantled and transferred back to the north portal, while the bulk of the machine will be brought back through the tunnel. It will be reassembled, ready to launch for the second bore of the tunnel.

Why is the TBM transferred back to the north portal to do the second bore of the tunnel? Why not start the second bore from the south portal?

I am genuinely curious. I am sure there is a good reason, does anyone know why the tunnel is bore in this way?

 

[ABB125]

Why is the TBM transferred back to the north portal to do the second bore of the tunnel? Why not start the second bore from the south portal?

I am genuinely curious. I am sure there is a good reason, does anyone know why the tunnel is bore in this way?

All the equipment is set up at the north portal, which was specifically designed for launching TBMs. For example, all the slurry processing machinery will be there.

 

[edwin_m]

All the equipment is set up at the north portal, which was specifically designed for launching TBMs. For example, all the slurry processing machinery will be there.

I imagine turning it 180 degrees would involve dismantling and reassembling it to the same extent as would be needed to transport it back to the other end of the tunnel.

 

[zwk500]

I imagine turning it 180 degrees would involve dismantling and reassembling it to the same extent as would be needed to transport it back to the other end of the tunnel.

moving everything to the other end of the tunnel would involve far more work. Especially for the parts that don't fit through the tunnel (there's a hell of a lot of support equipment at the base), they'd need to be road hauled over to the new site. Pulling the whole thing back and starting again from a point a few meters over requires comparatively minor realigning work.

 

[Winthorpe]

All the equipment is set up at the north portal, which was specifically designed for launching TBMs. For example, all the slurry processing machinery will be there.

I imagine turning it 180 degrees would involve dismantling and reassembling it to the same extent as would be needed to transport it back to the other end of the tunnel.

moving everything to the other end of the tunnel would involve far more work. Especially for the parts that don't fit through the tunnel (there's a hell of a lot of support equipment at the base), they'd need to be road hauled over to the new site. Pulling the whole thing back and starting again from a point a few meters over requires comparatively minor realigning work.

Thanks everyone. I didn't consider all of the support equipment behind the TBM.

Such good news that the first full bore is complete.

 

[edwin_m]

moving everything to the other end of the tunnel would involve far more work. Especially for the parts that don't fit through the tunnel (there's a hell of a lot of support equipment at the base), they'd need to be road hauled over to the new site. Pulling the whole thing back and starting again from a point a few meters over requires comparatively minor realigning work.

Will it in fact be pulled back or just dismantled and reassembled? Some part at the front can't be pulled back because the segments are inserted behind the cutter so the cutter is bigger than the tunnel behind it.

It was also mentioned somewhere, possibly upthread, that one of the TBMs will be dismantled when its initial task is complete, and reassembled to bore a tunnel on the Birmingham branch.

 

[stuu]

Will it in fact be pulled back or just dismantled and reassembled? Some part at the front can't be pulled back because the segments are inserted behind the cutter so the cutter is bigger than the tunnel behind it.

It was also mentioned somewhere, possibly upthread, that one of the TBMs will be dismantled when its initial task is complete, and reassembled to bore a tunnel on the Birmingham branch.

I believe the cutter head is put on a lorry and driven round, the rest of the machine is taken back through the tunnel

 

[ABB125]

Will it in fact be pulled back or just dismantled and reassembled? Some part at the front can't be pulled back because the segments are inserted behind the cutter so the cutter is bigger than the tunnel behind it.

It was also mentioned somewhere, possibly upthread, that one of the TBMs will be dismantled when its initial task is complete, and reassembled to bore a tunnel on the Birmingham branch.

I believe the cutter head and associated bits will be removed and taken back to the start by road, but the majority of the machine will be pulled back through.

Yes, the machine will then be used to note one of the two Bromford tunnels. I'm guessing it'll be the second one, because based on the amount of work that's already happened at Bromford east portal, I'd have thought that the portal will be ready before the second Long Itchington bore is complete

 

[Snow1964]

I believe the cutter head is put on a lorry and driven round, the rest of the machine is taken back through the tunnel

The cutter head will be too big to fit through, it would be the diameter of the cut (without the tunnel lining).

The remainder is on wheels that run on the lined tunnel, so can be pulled back through.

The problem with turning it around, and boring it other way, is that all the muck removal and segments would be at the wrong end.

Very occasionally TBMs are turned, the landward one at Calais on Eurotunnel was split into sections and turned around on special units, but then need to deal with getting the muck and segments to the machine possibly by taking it all the way through other tunnel.

 

[hwl]

Why is the TBM transferred back to the north portal to do the second bore of the tunnel? Why not start the second bore from the south portal?

I am genuinely curious. I am sure there is a good reason, does anyone know why the tunnel is bore in this way?

The cutter head will be too big to fit through, it would be the diameter of the cut (without the tunnel lining).

The remainder is on wheels that run on the lined tunnel, so can be pulled back through.

The problem with turning it around, and boring it other way, is that all the muck removal and segments would be at the wrong end.

Very occasionally TBMs are turned, the landward one at Calais on Eurotunnel was split into sections and turned around on special units, but then need to deal with getting the muck and segments to the machine possibly by taking it all the way through other tunnel.

The rear 90+% length wise can be pulled back through.