[U/C] M2 North-South Motorway

[ChillyPhilly]

I'm a bit weary of the over-politicisation of this project, which has been necessary for several decades now.

Equally, there are other transport priorities that will undoubtedly be ignored for at least another half decade based on Marshall's admission that the next stretch of the Motorway won't start until next term.

My biggest concern is for jobs. That was the reason the project was being broken into parts.

Edit: I made this a while back and am bringing it back up as a refresher.

The reason for no tunnel or trench in certain locations is due to the water table.

[Stryker]

A two lane tunnel is an absolute waste of time and is just going to create a bottleneck. They obviously haven't heard of the congestion problems with Sydney's M5 Tunnel if this is what they're considering for Adelaide. To future proof the South Road Motorway it must continue to be 3 lanes all the way no matter what the eventual decision is.

[A-Town]

A two lane tunnel is an absolute waste of time and is just going to create a bottleneck. They obviously haven't heard of the congestion problems with Sydney's M5 Tunnel if this is what they're considering for Adelaide. To future proof the South Road Motorway it must continue to be 3 lanes all the way no matter what the eventual decision is.

Agreed. If they're going to tunnel it, do it right and make it 3 lanes each way.

[how good is he]

While I totally agree after looking into tunnel boring machines, Wiki says “Tunnel diameters can range from one metre (3.3 ft) to 17.6 metres (58 ft) to date.“ https://en.m.wikipedia.org/wiki/Tunnel_boring_machine

I wonder if that’s the reason for 2 lanes (x 2)? For say 6 lanes x 3m width (plus say 3m width to allow for side buffers & centre section) they would need a TBM capable of doing approx 21m.

[SBD]

While I totally agree after looking into tunnel boring machines, Wiki says “Tunnel diameters can range from one metre (3.3 ft) to 17.6 metres (58 ft) to date.“ https://en.m.wikipedia.org/wiki/Tunnel_boring_machine

I wonder if that’s the reason for 2 lanes (x 2)? For say 6 lanes x 3m width (plus say 3m width to allow for side buffers & centre section) they would need a TBM capable of doing approx 21m.

The Heysen Tunnels are three lanes each, bored in hard rock, so it is possible in rock, but the ground under South Road is probably different. There are probably engineering considerations about how close the two tunnels can be to each other and to the surface. There might also be legal considerations if they are under private property not just the road reserves.

Tunnelling technology has probably developed in the last ten years, so worth revisiting, but I doubt the conclusion will actually change.

[how good is he]

Yes 3 lanes can be done with one boring machine but my point is 6 lanes can’t. Therefore they will need to use 2 boring machines to do 6 lanes (ie. 3 lanes in each direction). So obviously using 2 TBMs will be a lot more expensive than using 1 TBM for 2 x 2 lanes.
Further they could potentially complete the project in half the time if they used 2 boring machines doing 2 x 2 lanes ie 4 total lanes ie One TBM from the North meeting one TBM from the South.

[SBD]

Yes 3 lanes can be done with one boring machine but my point is 6 lanes can’t. Therefore they will need to use 2 boring machines to do 6 lanes (ie. 3 lanes in each direction). So obviously using 2 TBMs will be a lot more expensive than using 1 TBM for 2 x 2 lanes.
Further they could potentially complete the project in half the time if they used 2 boring machines doing 2 x 2 lanes ie 4 total lanes ie One TBM from the North meeting one TBM from the South.

The picture and video on the previous page show two separate tunnels. One seems to be under the surface road and the other seems to be offset to the left. I have no idea how deep it has to be to legally pass below private property. Safety considerations will require regular transverse tunnels connecting the two tubes, so they will have to be at about the same level. Otherwise there would need to be separate escape tunnels too.

[1NEEDS2POST]

Yes 3 lanes can be done with one boring machine but my point is 6 lanes can’t. Therefore they will need to use 2 boring machines to do 6 lanes (ie. 3 lanes in each direction). So obviously using 2 TBMs will be a lot more expensive than using 1 TBM for 2 x 2 lanes.
Further they could potentially complete the project in half the time if they used 2 boring machines doing 2 x 2 lanes ie 4 total lanes ie One TBM from the North meeting one TBM from the South.

It's possible, in fact you can fit three lanes in each direction.

https://www.tunneltalk.com/TunnelCast-S ... roject.php
In St Petersburg, there are plans for such a tunnel. The TBM has been ordered, but construction has been halted due to funding. It will feature a 19.25 m diameter TBM.
http://www.tunnelsonline.info/news/st-p ... -confirmed

[how good is he]

Ha! I found your article dated 2011 with a heading of Mega Aspirations! It was never even started.
See below article in 2017..

https://www.tunneltalk.com/Russia-12Dec ... rsburg.php
Construction of the supersized Orlovsky TBM bored tunnel under the Neva was approved by the Government of St Petersburg in 2008. The project assumed construction of a double-deck, six-lane tunnel of about 1km long, connecting the Piskarevsky Prospect with the Smolny embankment. However the new Governor of St Petersburg Georgy Poltavchenko, who was appointed to his position in 2011, suspended the project because of its high cost. The initial estimate for the project was RUB47.7 billion which later increased to some RUB 70 billion.

Surprise, surprise... now likely a 2 x 2 lane tunnel/TBM

St Petersburg Neva River highway revival
07 Mar 2019
Eugene Gerden reporting from Moscow for TunnelTalk
The Russian Federal Government, together with the authorities of the St Petersburg region, plans to resume building of the Orlovsky highway project but this time as parallel 10.3m diameter tunnels of about 2,200m long to accommodate two traffic lanes in each direction at a depth of 9m beneath the bed of the Neva River, rather than as the single-tube double-deck tunnel of three lanes on each deck developed back in 2007 using a record-breaking 19m diameter TBM proposed and procured in its design by Herrenknecht of Germany.

https://www.tunneltalk.com/Russia-04Mar ... rsburg.php

[ChillyPhilly]

Maybe it will be a cut-and-cover tunnel?

[Spotto]

Confirmed by Marshall this morning on Adelaide Radio, this road construction won’t start this term. Which means we will have re-announcement of the re-announcement, how many times will this be announced before the work actually starts. it’s very clear that it won’t be done this side of the next state election so I guess we will have at least 4 more announcements, over the next couple of Fed budgets and State ones.

By the end of this year we’ll have the rest of the corridor pretty much finished and R2P will follow in 2022. But we’ll be waiting until long after then for the final part to START CONSTRUCTION. Surely Libs could fast track this to start in maybe 2020/2021?

If Labor had nailed this down before or just after the last election, the tunnel link would be preparing to get underway within the coming months as Darlington and the Northern Connector wind down. Contract some of the same companies and migrate crews over, keep a perpetual state of construction on the corridor.

[claybro]

[quote=kymbosa post_id=181390 time=<a href="tel:1560738196">1560738196</a> user_id=1261]
Confirmed by Marshall this morning on Adelaide Radio, this road construction won’t start this term. Which means we will have re-announcement of the re-announcement, how many times will this be announced before the work actually starts. it’s very clear that it won’t be done this side of the next state election so I guess we will have at least 4 more announcements, over the next couple of Fed budgets and State ones.

By the end of this year we’ll have the rest of the corridor pretty much finished and R2P will follow in 2022. But we’ll be waiting until long after then for the final part to START CONSTRUCTION. Surely Libs could fast track this to start in maybe 2020/2021?

If Labor had nailed this down before or just after the last election, the tunnel link would be preparing to get underway within the coming months as Darlington and the Northern Connector wind down. Contract some of the same companies and migrate crews over, keep a perpetual state of construction on the corridor.
[/quote]

Labour had no plan for a tunnel, and in fact had no "plan" for the middle section at all by the time of the last state election. Had they won the last state election, things would pretty much be as they are now. Still waiting for the study of the concept of the plan.. as it has been for the last decade. Both party's have been playing politics with this for 50 odd years.

[SBD]

[quote=kymbosa post_id=181390 time=<a href="tel:1560738196">1560738196</a> user_id=1261]
Confirmed by Marshall this morning on Adelaide Radio, this road construction won’t start this term. Which means we will have re-announcement of the re-announcement, how many times will this be announced before the work actually starts. it’s very clear that it won’t be done this side of the next state election so I guess we will have at least 4 more announcements, over the next couple of Fed budgets and State ones.

By the end of this year we’ll have the rest of the corridor pretty much finished and R2P will follow in 2022. But we’ll be waiting until long after then for the final part to START CONSTRUCTION. Surely Libs could fast track this to start in maybe 2020/2021?

If Labor had nailed this down before or just after the last election, the tunnel link would be preparing to get underway within the coming months as Darlington and the Northern Connector wind down. Contract some of the same companies and migrate crews over, keep a perpetual state of construction on the corridor.

Labour had no plan for a tunnel, and in fact had no "plan" for the middle section at all by the time of the last state election. Had they won the last state election, things would pretty much be as they are now. Still waiting for the study of the concept of the plan.. as it has been for the last decade. Both party's have been playing politics with this for 50 odd years.
[/quote]

Tom K was on Twitter a couple of days agocomplaining that the government was even thinking about the remaining bit before it had started work on R2P (which he claimed has not started yet). As far as I can tell, he DOES NOT WANT a freeway built across his electorate until he is ready to retire.

[muzzamo]

A two lane tunnel is an absolute waste of time and is just going to create a bottleneck. They obviously haven't heard of the congestion problems with Sydney's M5 Tunnel if this is what they're considering for Adelaide. To future proof the South Road Motorway it must continue to be 3 lanes all the way no matter what the eventual decision is.

The most recent video with the options in it screams of the minister telling the department to produce a video so that he could announce something.

I don't think it should be taken too literally at all in terms of number of lanes etc.

[Westside]

Surely the $200M odd for the design will include some proper traffic modelling.

Depending on the location of the tunnel entrances, you may find 2 lanes is entirely appropriate. For example, they could aim this for primarily N-S freight movements and restrict city-bound movements. However, I doubt this will happen. After all, the aim of this project is to give Boothby residents an unobstructed 1 person per vehicle drive to their city jobs, right? </sarcasm>