Looks like someone has been talking to someone who knows about engineering. Building the line 10m down has issues getting under FSS tracks and the Yarra without a steep grade where the station needs to go. Bored tunnels will massively reduce the need to acquire and demolish buildings. Minister is quoting the cost as the same, I assume a formal estimate has been done. Now just a standard construction project.

Melbourne Metro rail: Tunnels to go deeper underground to keep trams running

Will decision to go with Tunnel Boring Machines most of the length will be more expensive or less expensive than large sections of 'cut and cover'? The deeper dive makes sense though, it was going to be a fairly steep section down to the Yarra otherwise.

The approach to building this vital infrastructure is becoming more and more sensible and could lead to a much better outcome for Melbourne.

The approach to building this vital infrastructure is becoming more and more sensible and could lead to a much better outcome for Melbourne.

Certainly appears to be the case rather than have made a bum decision in the first place and sticking with it no matter what!
BUT is that by design or accident?
I hope that it is by design.

Actually this is the way all large engineering projects are done, the first draft of the plan is just that a first draft, its a wish list of what they would like, it gives the engineers something to get there head around. An enginnering study  is then done looking at ALL factors, it is not until then can the final design and costings be done.

It is likely that in a place like the Melbourne city centre a deeply bored tunnel would be cheaper, there will be less disruption and they do not have to shift any services. One must apreciate though they do NOT know what will work until they have done the geo-phsyical and all other investigations, one assumes given this announcement they must now know a tunnel can be successfully bored at a decent depth and they not trying to bore through mud or badly fractured ground.

woodford

Will decision to go with Tunnel Boring Machines most of the length will be more expensive or less expensive than large sections of 'cut and cover'? The deeper dive makes sense though, it was going to be a fairly steep section down to the Yarra otherwise.

Cut and cover is cheap and quick if you don't run into utilities that have to be relocated. Swanston St is the opposite of that.

Using a deep tunnel means that they won't have to do nearly as many property resumptions to get construction vehicle access compared to cut & cover, either. It's also a chance to use only 2 launch/retrieval/turning pits for the TBMs instead of the 4 that cut and cover would need. They could even get down to 1 TBM too, if they're feeling really game. The real issue is going to be access to the station at CBD North/Melbourne Central now.

Being 40 metres underground you would expect that they will now dive under all the City Loop structures?

I was mainly referring to the escalators that they'll want to put in.

If you travel on Praha (Prague) Métro
they have some doozies of escalators between the platform and ground level.

The Stations double up as a bomb shelter !

Being 40 metres underground you would expect that they will now dive under all the City Loop structures?

40 metres would in many places be the current depth of the loop so it is hard to see how 40 metres would allow the new line to fit under the current one.

I was mainly referring to the escalators that they'll want to put in.

Okay - yeah I suppose that's a consideration.

40 metres would in many places be the current depth of the loop so it is hard to see how 40 metres would allow the new line to fit under the current one.

I believe at that exact point (under Swanston Street) Melbourne City Loop is at its most shallow point on the line.

Regarding Access to CBD North, the original designs for the Cut-and-cover model had the entrances coming up into the middle of Swanston Street, as see here. With the acquisition of the West Corner of the Swanston/La Trobe Street corner, I assume all access will be located under there with a combination of escalators and elevators leading to the platforms. I also assume that side of the road will be linked to the Melbourne Central Concourse somewhere around the McDonalds there.

Direct access to Platforms 3 and 4 would be nice, but I don't think they will run close enough to meet.

Being 40 metres underground you would expect that they will now dive under all the City Loop structures?

40 metres would in many places be the current depth of the loop so it is hard to see how 40 metres would allow the new line to fit under the current one.

The new cross town line in London threaded itself between two existing tunnels with only inches to spare.

Is it just me or does anyone else think matthew guy is an absolute flog ? If I was a politician and the opposition had a good idea I would probably compliment them on a good job, but this bloke vehemently puts down every single thing. He wasn't a good planning minister and I think he's a bitter man for getting kicked out of office.  His comments make him look stupid when he say's Labour have botched it already. What would it have been called if the Libs built it via fishermans bend ? The man suffers from short memory. Going deeper with the tunnel in my opinion is sensible and as mentioned interferes less with potential obstacles.

How does this guy think labour has botched it ? Thinking about the alternate project approach which he has backed in the past the reason for the change was to avoid cut and cover I think and the issue with the yarra river. Is this correct ?

When Denis Napthine was trying to find excuses to dump Swanston Metro in favour of their own (much more property-developer friendly) "Fisherman's Bend" Metro, they used to the supposed only choice of cut and cover as a smoke-screen. It was going to be far too disruptive, they said, despite the fact that cut and cover would have resulted in a very steep grade between Melbourne Central and the Yarra River.

Their appalling lack of a public transport vision is part of the reason why they're no longer in office; imagine spending billions on the Fisherman's Bend Metro in the vain hope that people might actually use it - while the Swanston Street/St Kilda Road trams remain overflowing. They didn't seem to grasp the fact that they had been elected by the people - not by property developers looking for a sweetener for their new tower precinct.

He wasn't a good planning minister and I think he's a bitter man for getting kicked out of office.

On the contrary, he was an excellent planning minister. He hardly said 'no' to anything, that's why city streets are turning into cold dark canyons that never see the sun. Thank God that Fisherman's Bend Metro never got off the ground... I'm not entirely in favour of billions being spent on the Swanston Street Metro but at least it will actually go places that are useful to most Melbourne people.

It is almost as if the planners have no idea of modern tunnel boring methods. When it was first announced as a cut'n'cover job I wondered why they would not go deeper and do it all with TBMs. I am no civil engineer, but I do read enough to know that modern TBMs can do a faster and cheaper job than CNC, despite their higher initial outlay.

On the contrary, he was an excellent planning minister. He hardly said 'no' to anything

Especially to his mates on Phillip Island... Well, until his colleagues told him that preferential rezoning looks a hell of a lot like corruption and that he should reverse the decision. And his 'mate' sued him for doing that.
And who picked up the tab at the end of the day? The Victorian Taxpayer, of course.

Did Napthine and the liberals actually think the public would not question the idea of cut and cover so was the idea of cut and cover as a method the idea of the labour guys or the liberals?

Did the firm quoting and managing the Melbourne metro tunnel under labour also look at the Fisherman Bend option for Napthine?

This may not come as a shock to some but the strong rumour at the time was the Fisherman Bend development was partially owned and probably still is by the Baillieu Family.

It is almost as if the planners have no idea of modern tunnel boring methods. When it was first announced as a cut'n'cover job I wondered why they would not go deeper and do it all with TBMs. I am no civil engineer, but I do read enough to know that modern TBMs can do a faster and cheaper job than CNC, despite their higher initial outlay.

It's amazing what can be accomplished with them too. As you pointed out earlier London's Cross Rail is being done almost entirely with TBM's and they can be manoeuvred with incredible accuracy to avoid existing structures - they're really amazing pieces of modern engineering. I'm not an engineer either but I'm certain there would be cost advantages to doing almost all the 9km of Swanston Metro with them as opposed to other methods. If you think about it they could probably have done cut and cover for most of the length of St Kilda Road as well.

Golly, you guys are laying it on a bit thick!

Can't you take your political prejudices and start up a dedicated "I hate state Liberals too" tread to compliment the existing "I hate Abbott" and "I hate Turnbull" threads?

You can get it all out of you system there and leave "secular" threads to intelligent, non political discussion.

If @Bogong those comments are directed at me then ok. I accept that. What I am trying to point out is the excuse by Napthine for the reasons to alter the original "shovel ready" plan was a smoke screen and more about property development.

The more I think through the plan the more I like it. What I do not yet get is if the business case is not yet done then how could the project have been shovel ready in the eyes of infrastructure Australia?

It is almost as if the planners have no idea of modern tunnel boring methods. When it was first announced as a cut'n'cover job I wondered why they would not go deeper and do it all with TBMs. I am no civil engineer, but I do read enough to know that modern TBMs can do a faster and cheaper job than CNC, despite their higher initial outlay.

It's amazing what can be accomplished with them too. As you pointed out earlier London's Cross Rail is being done almost entirely with TBM's and they can be manoeuvred with incredible accuracy to avoid existing structures - they're really amazing pieces of modern engineering. I'm not an engineer either but I'm certain there would be cost advantages to doing almost all the 9km of Swanston Metro with them as opposed to other methods. If you think about it they could probably have done cut and cover for most of the length of St Kilda Road as well.

Yeah, and when they finish, if the TBMs are not rooted, then they should turn them around and bore a whole lot more tunnels for the Metro. Our underground sucks in comparison to other cities.

It is almost as if the planners have no idea of modern tunnel boring methods. When it was first announced as a cut'n'cover job I wondered why they would not go deeper and do it all with TBMs. I am no civil engineer, but I do read enough to know that modern TBMs can do a faster and cheaper job than CNC, despite their higher initial outlay.

It's amazing what can be accomplished with them too. As you pointed out earlier London's Cross Rail is being done almost entirely with TBM's and they can be manoeuvred with incredible accuracy to avoid existing structures - they're really amazing pieces of modern engineering. I'm not an engineer either but I'm certain there would be cost advantages to doing almost all the 9km of Swanston Metro with them as opposed to other methods. If you think about it they could probably have done cut and cover for most of the length of St Kilda Road as well.

Yeah, and when they finish, if the TBMs are not rooted, then they should turn them around and bore a whole lot more tunnels for the Metro. Our underground sucks in comparison to other cities.

I believe the ones being used on the North West Rail Link in Sydney are going to be parked in a dead end and just left there - I suppose they're either not worth recovering and/or worn out.

I just saw a news story on Channel Nine news and the latest animation from the Andrews government shows the new metro line being bored under the existing City Loop (as you'd assume).

I believe the ones being used on the North West Rail Link in Sydney are going to be parked in a dead end and just left there - I suppose they're either not worth recovering and/or worn out.

I just saw a news story on Channel Nine news and the latest animation from the Andrews government shows the new metro line being bored under the existing City Loop (as you'd assume).

Watched this also. Looks like the tunnels will arrive within a few metres of the current network.  Should make changing a little easier for those who just want to change trains.  For those who want to exit or enter the station the extra distance will be negligible.

Andrews is finally get on with the job. @don_dunstan the opposition leaders comments were maladaptive and ill informed as usual.  The Libs seem to think it will cost around $400m more.

https://www.railpage.com.au/news/s/metro-rail-project-digging-deeper-could-cost-more