On Monday Alice the Tunnel Boring Machine broke through at Waterview after tunnelling for the last 10 months.
And here’s a video of it happening.
One of the things that is really impressive is just how accurate the machine is with it being within 10mm of where they planned for it to exit. All up almost 400,000m³ of spoil was removed from the 2.4km tunnel and just over 12,000 concrete tunnel lining segments have been installed.
Here’s the press release that goes with it which provides a lot more information
The first of the twin road tunnels that will connect Auckland’s Southwestern and Northwestern motorways as part of the NZ Transport Agency’s Waterview Connection project has been built.
Alice, the tunnel boring machine, broke into daylight this afternoon, at the end of her 10-month 2.4km underground journey from Owairaka to Waterview.The tunnel she has built is the tenth largest diameter tunnel in the world and the longest road tunnel in New Zealand. Once opened in early 2017, it will carry three lanes of southbound traffic up to 40 metres below Avondale and Waterview in west Auckland.
The NZ Transport Agency’s Highways Manager for Auckland, Brett Gliddon, says the tunnel’s completion is a significant milestone for the $1.4bn project to build the new 5km, six-lane motorway link from the Great North Road interchange at Waterview to Maioro Street in Mt Roskill and complete the long awaited Western Ring Route.
“This is a fantastic achievement. Our construction partners on the Well-Connected Alliance completed the breakthrough safely and ahead of schedule,” Mr Gliddon says.
“It is a huge engineering feat for New Zealand, one that is attracting worldwide attention. It demonstrates that with local and international experience and expertise, we can deliver infrastructure to equal the best in the world.”
Mr Gliddon says Alice will now be turned around to bore the northbound tunnel.
“While it is not unusual internationally to turn a tunnel boring machine, what is extraordinary about this turn is the sheer size of the machine and the constricted space in which the manoeuvre will take place.”At 90m long and weighing 3,100 tonnes, Alice is big. The cutting head and its three trailing gantries will be disconnected and each piece taken one at a time from the completed tunnel and turned.
Only when all of Alice’s parts are in place and reconnected – in early 2015 – will tunnelling resume to construct the second tunnel.
The conveyor system that removes excavated material and other services required for the machine’s operation will also be turned and will follow Alice as she journeys south. By the completion of the second tunnel, they will extend the length of both tunnels – nearly 5km.
A fourth gantry, which operates independently of Alice to install a culvert on the floor of the tunnel, will be the last to be turned. This culvert will carry the services needed for operation of the tunnels once they have been completed.The machine’s drive south from Waterview to Owairaka is expected to be completed in about October next year. Approximately a year of work will then remain to complete the mechanical and electrical fit-out of the tunnels, including completing ventilation buildings at both ends and constructing 16 cross passages to connect the tunnels.
The entire project – which also involves building the surface connections to the existing motorways, 9km of new cycleway, new community amenities such as walkways, playgrounds and skateparks, and planting approximately 150,000 trees and shrubs – is due to be completed in early 2017.
The Waterview Connection is one of five projects to complete the Western Ring Route as an alternative motorway to SH1 through central Auckland and across the Auckland Harbour Bridge. It is prioritised by the Government as one of its Roads of National Significance because of the contribution it will make to New Zealand’s prosperity by underpinning economic growth and sustainable development for Auckland and its regional neighbours.
The project is being delivered by the Well-Connected Alliance which includes the Transport Agency, Fletcher Construction, McConnell Dowell, Parsons Brinckerhoff, Beca Infrastructure, Tonkin & Taylor and Japanese construction company Obayashi Corporation. Sub-alliance partners are Auckland-based Wilson Tunnelling and Spanish tunnel controls specialists SICE.
As well as designing and building the Waterview Connection, the alliance will operate and maintain the 5km motorway for 10 years from its completion.
Also if you’re interested in how the TBM will be turned around, this gives some more info. Click to enlarge (2.8MB)
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Great to see that it came in ahead of schedule as well.
Now that we have this expertise in NZ, the CRL should be a doddle and there is no reason why that drilling shouldn’t also be ahead of schedule.
All we need now is for the National led government to realign its Auckland transport policy back to the centre – I look forward to it.
Seems like NZ is really getting its sh!t together on completing big projects. Great stuff.
One problem is most of the tunnelers and experts are one who have been flown in from elsewhere just got the job and will leave after Waterview for something else unless we can get CRL lined up to dovetail on it.
In saying that I’m sure many of the locals involved have gained a lot which will help come CRL time.
This is a point made by Fletchers in this article over the weekend.
http://www.nzherald.co.nz/fletcher-building-limited/news/article.cfm?o_id=66&objectid=11332252
Matt point taken, but how much will the Waterview tunnel and CRL tunnels be alike from a overseas expertise point of view?
The Waterview tunnels specifically avoided tunnelling through the hard volcanic rock layers (it went under them – hence the tunnel grades at each end to dive under the volcanic flows) as it avoided them as much as possible – makes for cheaper TBM and faster tunnelling.
Whereas the CRL tunnels will just be through whatever rock is in the way, which will be a lot of hard (volcanic and other) rock types in some places and of course the TBM will be smaller so presumably easier to manage, requiring less crew and presumably less “segments” per ring than the 10 used at Waterview?
Will still need local expertise – which will be available – unless its taken up and used on other projects elsewhere in Nz or Australia.
And regardless of when CRL starts the tunnelling experts will still come in from overseas and I’d expect even if the CRL tunnels and TBM were ready to go as Waterview TBM finished up that a different tunnelling team would be used for CRL over Waterview’s tunneling team anyway, yes some would be on both, but I see Waterview and CRL are completely different tunnels, just happening to be in the same town more or less adjacent in time.
Now maybe if AWHC was being built right after Waterview (heaven forbid that ever happens, but with the current Government anything is possible), then yes I’d see a lot of commonality with these two large diameter tunnels and so doing one after the other would make some sense (but not financial sense).
And if AWHC is even a decade after Waterview, the technology used will have moved on a lot in comparison, so different skills would be needed/used anyway when that comes to pass.
Happy to be shown otherwise but my understanding is that apart from the southern end where they have to dig out the junction, the TBM part is through sandstone
The only basalt is at the southern end and will be trenched through similarly to the south end of waterview tunnels. TBM will only be used on softer sandstone, same as waterview.
Not a lot of surveying involved, TBM is laser guided
I understand that the plan is to dismantle Alice once the job is done. Seems like a waste of a huge investment.
Alice had been sold back to the company that built her who will reuse some of the parts for other TBMs
Should we keep it as a museum peice because that is all it will be useful for….
It is being disposed of because it will be spent.
Unless there is a push to make 3 lane tunnels the NZ “standard” there really isn’t much value in keeping an old TBM in a warehouse waiting for the next project,
long tunnels are fairly rare and bespoke items in NZ and thus the TBMs also tend to be one offs,
(the last big road tunnels at Johnstone’s hill didn’t even use a TBM)
My understanding is that the TBM will be mostly stuffed after the two tunnels and will be stripped for parts and scrap.
A TBM, is designed to last long enough to do the exact job required and no more, so Alice TBM is designed to cut 5KM of tunnels through the intended rock and strata at Waterview – no more, no less.
Once its done, that it will be totally worn out on all the TBM bits that matter for a TBM to be used. Some of its parts could be reused but scrap is the usual destination for these machines.
The Channel Tunnel TBM, once it completed the Channel tunnels was used one last time to dig its own grave – a shortish side chamber tunnel, where it was simply parked, turned off, then entombed with back filled material and left in place.
It is my understanding that the CRL is mostly a cut and cover tunnel, because it goes through volcanic rock.
TBMs are purchased with a buyback for the manufacturer unless you are making a one way tunnel, they cannot go in reverse.
I understand that there is a partly dismantled TBM under Mairangi Bay which was left there after the completion of the Rosedale Sewerage treatment discharge tunnel (3 km).
Your understanding may be flawed. The bored section is FAR longer than the cut and cover, it is cut and cover at the bottom because it is too shallow to bore.
That’s correct, the CRL cut and cover section is only some 700m.
Well done to the surveyors in their accuracy and precision to guide the TBM on its route.