[U/C] M2 North-South Motorway

[SBD]

I think I heard this morning that the TBM(s) get built in a big hole, so there's a lot of digging needed before assembly can begin.

I imagine that one of them will proceed north from the north portal of the southern tunnel to the south portal of the north tunnel - this could even be how part of the trench is excavated!

Leaving them underground to rust and decay does not seem like a practical solution, just in terms of where that could be since there will be a road portal right in front, and rust would eventually lead to subsidence if they drove under the end of the surface roads.

If possible, reusing some of the TBM for a future Mount Barker/Murray Bridge link would be attractive, if only the cutting head needs to be changed from western suburb silt to Adelaide Hills rock. A tunnel under Cross Road is not an attractive solution as it extends the long decline we already have problems with. A KPMG report a few years ago had a "short south" option that built a freeway from south of Mount Barker to meet the NSM in the Darlington area by a mix of bridges and tunnels. This would avoid the long steep grade, and provide an alternate route from Mount Barker and Murray Bridge to city and suburban destinations for both commuters and road freight.

They don't "bury" them, they drive them into the ground in a burial chamber and concrete them in. The British did it after the Channel Tunnel with their TBM's. Interestingly enough the French recovered theirs

That still involves digging 100 metres extra tunnel, then leaving the void created filled with steel (the machine). I guess you avoid subsidence by lining that extra 100 metre tunnel with the same concrete lining for the rest of the tunnel. My point is that you have now drilled an extra 100 metres (or more) below the surface/trench road. At the north end, if you considered doing that, you might as well tunnel under the Torrens and "surface" in the existing trench at which point it's accessible to destroy and send to the scrap metal yard.

[abc]

I think I heard this morning that the TBM(s) get built in a big hole, so there's a lot of digging needed before assembly can begin.

I imagine that one of them will proceed north from the north portal of the southern tunnel to the south portal of the north tunnel - this could even be how part of the trench is excavated!

Leaving them underground to rust and decay does not seem like a practical solution, just in terms of where that could be since there will be a road portal right in front, and rust would eventually lead to subsidence if they drove under the end of the surface roads.

If possible, reusing some of the TBM for a future Mount Barker/Murray Bridge link would be attractive, if only the cutting head needs to be changed from western suburb silt to Adelaide Hills rock. A tunnel under Cross Road is not an attractive solution as it extends the long decline we already have problems with. A KPMG report a few years ago had a "short south" option that built a freeway from south of Mount Barker to meet the NSM in the Darlington area by a mix of bridges and tunnels. This would avoid the long steep grade, and provide an alternate route from Mount Barker and Murray Bridge to city and suburban destinations for both commuters and road freight.

They don't "bury" them, they drive them into the ground in a burial chamber and concrete them in. The British did it after the Channel Tunnel with their TBM's. Interestingly enough the French recovered theirs

by my understanding that's still burying them

not everything going to plan with the one in the Snowy scheme
https://www.abc.net.au/news/2024-05-22/ ... /103875910

[Hooligan]

I think I heard this morning that the TBM(s) get built in a big hole, so there's a lot of digging needed before assembly can begin.

I imagine that one of them will proceed north from the north portal of the southern tunnel to the south portal of the north tunnel - this could even be how part of the trench is excavated!

Leaving them underground to rust and decay does not seem like a practical solution, just in terms of where that could be since there will be a road portal right in front, and rust would eventually lead to subsidence if they drove under the end of the surface roads.

If possible, reusing some of the TBM for a future Mount Barker/Murray Bridge link would be attractive, if only the cutting head needs to be changed from western suburb silt to Adelaide Hills rock. A tunnel under Cross Road is not an attractive solution as it extends the long decline we already have problems with. A KPMG report a few years ago had a "short south" option that built a freeway from south of Mount Barker to meet the NSM in the Darlington area by a mix of bridges and tunnels. This would avoid the long steep grade, and provide an alternate route from Mount Barker and Murray Bridge to city and suburban destinations for both commuters and road freight.

The short south option looked good, and would cost less than a cross road tunnel.

I personally like the short north option they also mentioned, extending Grand Junction road with a tunnel through the hills and having an at grade freeway connecting to the South Eastern Freeway just east of Mount Barker. I like this one because it also gives freight and alternative north-south option.

[dbl96]

Apparently TBMs aren't as expensive as I thought. This article gives a good run-down: https://tunnelcontact.com/pages/view/37 ... e-tbm-cost

Apparently they are around $1 million USD per metre of diameter, which is expensive, but in the scheme of things, not crazily so. That said, this is an Australia infrastructure project - you can be almost certain they will be overpaying for ours.

[SBD]

I think I heard this morning that the TBM(s) get built in a big hole, so there's a lot of digging needed before assembly can begin.

I imagine that one of them will proceed north from the north portal of the southern tunnel to the south portal of the north tunnel - this could even be how part of the trench is excavated!

Leaving them underground to rust and decay does not seem like a practical solution, just in terms of where that could be since there will be a road portal right in front, and rust would eventually lead to subsidence if they drove under the end of the surface roads.

If possible, reusing some of the TBM for a future Mount Barker/Murray Bridge link would be attractive, if only the cutting head needs to be changed from western suburb silt to Adelaide Hills rock. A tunnel under Cross Road is not an attractive solution as it extends the long decline we already have problems with. A KPMG report a few years ago had a "short south" option that built a freeway from south of Mount Barker to meet the NSM in the Darlington area by a mix of bridges and tunnels. This would avoid the long steep grade, and provide an alternate route from Mount Barker and Murray Bridge to city and suburban destinations for both commuters and road freight.

The short south option looked good, and would cost less than a cross road tunnel.

I personally like the short north option they also mentioned, extending Grand Junction road with a tunnel through the hills and having an at grade freeway connecting to the South Eastern Freeway just east of Mount Barker. I like this one because it also gives freight and alternative north-south option.

Short North would likely then eventually require a freeway supplement/replacement for Grand Junction Road to provide a better freight route down to the Port River Expressway. It's kind of surprising we don't hear about more runaway trucks coming down from Hampstead Road and failing to stop at Main North Road now. If they're all built, we'd end up with a freeway ring route anyway!

[rev]

I think I heard this morning that the TBM(s) get built in a big hole, so there's a lot of digging needed before assembly can begin.

I imagine that one of them will proceed north from the north portal of the southern tunnel to the south portal of the north tunnel - this could even be how part of the trench is excavated!

Leaving them underground to rust and decay does not seem like a practical solution, just in terms of where that could be since there will be a road portal right in front, and rust would eventually lead to subsidence if they drove under the end of the surface roads.

If possible, reusing some of the TBM for a future Mount Barker/Murray Bridge link would be attractive, if only the cutting head needs to be changed from western suburb silt to Adelaide Hills rock. A tunnel under Cross Road is not an attractive solution as it extends the long decline we already have problems with. A KPMG report a few years ago had a "short south" option that built a freeway from south of Mount Barker to meet the NSM in the Darlington area by a mix of bridges and tunnels. This would avoid the long steep grade, and provide an alternate route from Mount Barker and Murray Bridge to city and suburban destinations for both commuters and road freight.

The short south option looked good, and would cost less than a cross road tunnel.

I personally like the short north option they also mentioned, extending Grand Junction road with a tunnel through the hills and having an at grade freeway connecting to the South Eastern Freeway just east of Mount Barker. I like this one because it also gives freight and alternative north-south option.

Short North would likely then eventually require a freeway supplement/replacement for Grand Junction Road to provide a better freight route down to the Port River Expressway. It's kind of surprising we don't hear about more runaway trucks coming down from Hampstead Road and failing to stop at Main North Road now. If they're all built, we'd end up with a freeway ring route anyway!

Could do an elevated motorway between the superway and pretty much all the way to GJR which is 99% industrial along that stretch. The eastern part of GJR widen it and do a similar to the section between Torrens and Regency roads.

[Goodsy]

I think I heard this morning that the TBM(s) get built in a big hole, so there's a lot of digging needed before assembly can begin.

I imagine that one of them will proceed north from the north portal of the southern tunnel to the south portal of the north tunnel - this could even be how part of the trench is excavated!

Leaving them underground to rust and decay does not seem like a practical solution, just in terms of where that could be since there will be a road portal right in front, and rust would eventually lead to subsidence if they drove under the end of the surface roads.

If possible, reusing some of the TBM for a future Mount Barker/Murray Bridge link would be attractive, if only the cutting head needs to be changed from western suburb silt to Adelaide Hills rock. A tunnel under Cross Road is not an attractive solution as it extends the long decline we already have problems with. A KPMG report a few years ago had a "short south" option that built a freeway from south of Mount Barker to meet the NSM in the Darlington area by a mix of bridges and tunnels. This would avoid the long steep grade, and provide an alternate route from Mount Barker and Murray Bridge to city and suburban destinations for both commuters and road freight.

The short south option looked good, and would cost less than a cross road tunnel.

I personally like the short north option they also mentioned, extending Grand Junction road with a tunnel through the hills and having an at grade freeway connecting to the South Eastern Freeway just east of Mount Barker. I like this one because it also gives freight and alternative north-south option.

Short North would likely then eventually require a freeway supplement/replacement for Grand Junction Road to provide a better freight route down to the Port River Expressway. It's kind of surprising we don't hear about more runaway trucks coming down from Hampstead Road and failing to stop at Main North Road now. If they're all built, we'd end up with a freeway ring route anyway!

Sit at the Gepps Cross intersection, you'll see 10x more B Doubles with smoking brakes than you will at the base of the freeway

[ChillyPhilly]

Here are some of the renders recently released. They are available here to see more, just thought I'd post here for visual reference.

https://www.t2d.sa.gov.au/planning-desi ... gn#gallery

Looking south at the Northern Tunnels' northern portal at Torrensville:



The same view of the above but at night:



Looking south from the pavement on South Road:



West along the River Torrens:

[muzzamo]

From the Advertiser:


OVERPASSES COULD
SLASH $133m
FROM ROAD COSTS
By CAMERON ENGLAND and KARA PHILLIPS
05jun06
EXCLUSIVE
BUILDING overpasses rather than tunnels on South Rd could shave $133 million off the bill on the blowout-plagued projects, the state's peak resources body said yesterday.

This thread serves as a unique historical record.

The first mention in this thread is from 2006, with a proposal to user overpasses or underpasses instead of tunnels. I remember meeting some DPTI employees at a university job fair in about 2005 who had some renders of proposed South Road Tunnels.

26 years from conception to completion, assuming no further delays. Round it up to 30 to be safe I'd say.

[Prodical]

With the start timed to coincide with the next State election

[abc]

30 years to upgrade a road

it'll be 100 years before Adelaide sees an underground rail line... meanwhile Perth...

[Saltwater]

30 years to upgrade a road

it'll be 100 years before Adelaide sees an underground rail line... meanwhile Perth...

30 years to upgrade a road really does make it a once in a generation event. Hopefully it's worth it when built. The current plans are looking very good.

As for Perth, good on them as they've been at the centre of a once in 100 year mineral boom, and it's great to see they've funnelled some of that back into some decent infrastructure including a sizeable freeway network, underground rail through the city and an airport link. Stuff we could only dream of.

[rhino]

30 years to upgrade a road really does make it a once in a generation event. Hopefully it's worth it when built. The current plans are looking very good.

As for Perth, good on them as they've been at the centre of a once in 100 year mineral boom, and it's great to see they've funnelled some of that back into some decent infrastructure including a sizeable freeway network, underground rail through the city and an airport link. Stuff we could only dream of.

I recognise that - Perspective. Thanks for that!

[claybro]

[quote=Saltwater post_id=219450 time=<a href="tel:1723678794">1723678794</a> user_id=8131]
30 years to upgrade a road really does make it a once in a generation event. Hopefully it's worth it when built. The current plans are looking very good.

As for Perth, good on them as they've been at the centre of a once in 100 year mineral boom, and it's great to see they've funnelled some of that back into some decent infrastructure including a sizeable freeway network, underground rail through the city and an airport link. Stuff we could only dream of.

I recognise that - Perspective. Thanks for that!
[/quote]

The momentum that began Perths freeway network started in the 50’s/60’s and had little to do with the mining boom. A 2cent per litre levy (not a small amount at the time and equivalent of 20 cents per litre in today’s terms) was added to petrol to fund freeway construction. This enabled slow and steady pace at the start, and even when the levy was removed after a few years, the road reserves were well established, and momentum then only increased as the mining booms took their course. SA on the other hand, had never contemplated alternative revenues, due to lazy politicking on both sides. The road reserved that did exist were then too easily sold off, as no progress had been made in 20 years. Having said that I do believe Adelaide now has the opportunity to benefit in not having huge suburban interchanges in the older heritage suburbs.

[Saltwater]

Adelaide is quite unique in that large sections of our inner suburbs remain largely intact. Looking at the MATS plan is scary for what it would have done to Bowden / Hindmarsh - the whole area would have been completely obliterated. it's good that we've held onto our heritage.