High Speed Rail - Australia

[ozbob]

It does appear the Federal Labor Government is talking about true HSR.  I think the biggest risk to the project would be a change of Government Federally. Hence Ms, King wanting to bring the business case forward in time for the next Federal election.

A HSR track alignment between Sydney and Newcastle will be costly, probably the most costly stretch of HSR say between Sydney and SEQ per/km, but you get what you pay for!

[verbatim9]

Yeah I meant electric Fast Rail up to 200kph. All these terms getting thrown around gets confusing at times.

[SurfRail]

The issue for proponents of a medium speed or faster corridor will be that the cost of delivering any given speed doesn't scale fully in line with the differences.  Everything I've read suggests there is bugger all difference in cost in building something for 200km/h vs 300km/h.  The differences start to become more pronounced at higher speeds than 300km/h as the minimum curve and other physical requirements start getting quite pronounced, and offer limited benefit if you actually plan on stopping your train somewhere.  If you have to spend 80-90% as much on 200km/h as 300km/h, I don't see the point in faffing about, especially when huge chunks of tunnel are involved.  It could be that Sydney to Newcastle is in as many contiguous sections of tunnel as possible to get through the Cowan Bank and all the other interesting scenery on the way - emerging from and re-entering multiple tunnels set up to minimise the amount of tunnel (instead of just barrelling through with one tunnel over the whole distance) is probably a false economy.

[Gazza]

A HSR track alignment between Sydney and Newcastle will be costly, probably the most costly stretch of HSR say between Sydney and SEQ per/km, but you get what you pay for!

Also, I think the closer you get to Sydney, the more beneficial it is, since you have the commuter market filling up trains.

If you head south out of Sydney towards Canberra, the only real population centers you hit are the Southern Highlands  (Mittagong/Bowral/Moss Vale) 50,000 people, and then Goulburn, 33,000, and  then really nothing until Canberra 460,000.
A distance of 270km

If you head north out of Sydney.
You have Central Coast 327,000 then the City of Lake Macquarie, 197,000, and then finally Newcastle 150,000 and Maitland 77,000, so that's 750,000 people, in a distance of of 150km.

So much more people in a shorter distance means more boardings per km.
In particular, its those 327,000 people in the Central Coast that are between 50km and 70km away from Sydney that will really make this stack up.

[#Metro]

Going through the HSR Report Pile, it seems there already was consideration for the Sydney-Newcastle corridor as HSR.

Anthony Albanese, no less, commissioned that report in 2013.

Apart from updating the financial figures, what will a new report tell us that the old one didn't? 

Anthony Albanese has long supported a HSR network. In 2013, when he was Minister for Infrastructure and Transport, Albanese released the Phase 2 Report of its High-Speed Rail Study.

Sydney-Newcastle was costed at about $18.9b ($2013) which is about $24b in today's dollars.

$24b / 134 km route length => 175 million/km.

^ Not entirely convinced this is a credible unit figure given the terrain, high reliance on tunneling, and standard railway projects coming in at around these costs already. The all-tunnel CBD-Parramatta metro is coming in *at* $25 billion, or 1 billion/km.

Would you even make it half-way out of the city of Sydney with $25b and all tunnels? 

Notes

Federal Labor: High-Speed Rail Between Sydney and the Hunter
https://www.hawkerbritton.com/blog/2022/01/06/federal-labor-high-speed-rail-between-sydney-and-the-hunter/

High Speed  Rail Study Phase 2 Report
https://apo.org.au/sites/default/files/resource-files/2013-04/apo-nid33517.pdf

Revealed: The true cost of the Metro West line
https://www.smh.com.au/politics/nsw/revealed-the-true-cost-of-the-metro-west-line-20230410-p5czcg.html

[NothingToSay]

What sort of cost savings could we see if the stations were built further outside the city similar to how the Chinese HSR network was built?

[RowBro]

Going through the HSR Report Pile, it seems there already was consideration for the Sydney-Newcastle corridor as HSR.

Anthony Albanese, no less, commissioned that report in 2013.

Apart from updating the financial figures, what will a new report tell us that the old one didn't? 

Anthony Albanese has long supported a HSR network. In 2013, when he was Minister for Infrastructure and Transport, Albanese released the Phase 2 Report of its High-Speed Rail Study.

Sydney-Newcastle was costed at about $18.9b ($2013) which is about $24b in today's dollars.

$24b / 134 km route length => 175 million/km.

^ Not entirely convinced this is a credible unit figure given the terrain, high reliance on tunneling, and standard railway projects coming in at around these costs already. The all-tunnel CBD-Parramatta metro is coming in *at* $25 billion, or 1 billion/km.

Would you even make it half-way out of the city of Sydney with $25b and all tunnels? 

Notes

Federal Labor: High-Speed Rail Between Sydney and the Hunter
https://www.hawkerbritton.com/blog/2022/01/06/federal-labor-high-speed-rail-between-sydney-and-the-hunter/

High Speed  Rail Study Phase 2 Report
https://apo.org.au/sites/default/files/resource-files/2013-04/apo-nid33517.pdf

Revealed: The true cost of the Metro West line
https://www.smh.com.au/politics/nsw/revealed-the-true-cost-of-the-metro-west-line-20230410-p5czcg.html


https://www.theguardian.com/australia-news/2019/nov/23/sydney-light-rail-project-blows-out-to-29bn-almost-double-original-cost

Comparing Sydney Metro to HSR wont give you very good results though. Metro is confined in its tunnelling by the infrastructure surrounding it which requires much more rigorous impact assessments and land acquisition. This makes the cost much higher than if it were simply tunnelling through a mountain. You also get economy of scale. Its much less costly per km to buy a TBM for 100km than it is for 10km. The price of the TBM is spread over 10x as many km's.

[#Metro]

Megaproject - 2x Cost Escalation Potential

HSR will be a megaproject undertaking.

So, you would need to accept the potential of a 2x initial cost risk on this and be OK with that. It doesn't automatically mean its a bad/unviable idea - the report will figure that out.

Plenty of examples: LGCFR was 2x, Sydney Light Rail was 2x, Sydney Metro West was 2x, Inland Rail was 2x. Overseas HSR examples have not been encouraging - UK HS2, Sweden HSR (BCR well below 1), and California HSR (approaching 3x).

Flyvberg suggests "reference class forecasting" as a realistic way to estimate end-of-project costs for projects of this type.

A positive thing at least about a Newcastle proposal is that it will be trains vs lanes, rather than trains vs planes. So you would expect better patronage. Credit for that.

It raises the question - what is the plan to mitigate against a 2x scenario here?

Next, let's look at the economy of scale argument. Are there limits?

Tunnelling Speed Estimation

The UK HS2 website puts a TBM as being able to do 15 meters per day on average.

The Sydney-Newcastle alignment is about say 134 km. Let's assume 20% surface running in existing corridors.

So that leaves ~ 107 km of tunnel or 107,200 meters. At 15 meters per day, the TBM would take about 7,146.66 days to get to Newcastle from Sydney.

Divide by 365 days in one year => 19.57 years. This 20-year timeframe seems unreasonably long.

There are limits to the economy of scale aspect. Multiple TBMs would definitely be required to complete the project in a reasonable time, which would increase the cost. If anything, generally risk increases with scale for megaprojects.

Notes
Meet our giant Tunnel Boring Machines
https://www.hs2.org.uk/building-hs2/tunnels/meet-our-giant-tunnel-boring-machines/

To dig the tunnels, giant cutterheads at the front of the TBM rotate, cutting away at the earth. When digging, the earth is carried up the screw conveyor and out of the TBM within a slurry pipe or on a conveyor belt. On average they will dig up to 15 metres a day.

'Astonishing': cost of Inland Rail doubles to $30bn as review savages Coalition over project
https://www.theguardian.com/australia-news/2023/apr/06/astonishing-cost-of-inland-rail-doubles-to-30bn-as-review-savages-coalition-over-project

[Gazza]

The Sydney-Newcastle alignment is about say 134 km. Let's assume 20% surface running in existing corridors.

So that leaves ~ 107 km of tunnel or 107,200 meters. At 15 meters per day, the TBM would take about 7,146.66 days to get to Newcastle from Sydney.

Sorry thats not a very rigorous assumption, and of course you can look at the 2013 study to see the amount of tunnelling required.

Two fatal flaws

-15m a day assumes you are doing a single tunneling drive. Clealy it is possible to have multiple tunneling sites, work from either end, which is a common practice.
You cant argue its "increasing the cost".... relative to what? Its not like there are "cheaper" projects that did 100km of tunnel with 1 machine.

-Im not sure if you have travelled Sydney to Newcastle by land, but you don't need 107km of tunnel.
Certainly it is very rugged terrain as far as about Gosford/Ourimbah.
North of that point, to Newcastle is quite flat, and IIRC the HSR study had it more or less following the M1.

You wouldn't be tunnelling in terrain like this.

[#Metro]

Report Already Exists

There is already another completed report (recent too) - into a Sydney - Newcastle HSR link. Why not just release the existing report the NSW Government is sitting on, and let the public read it? UK Rail expert Andrew McNaughton (associated with UK HS2) wrote it.

Notes

NSW slams brakes on high-speed rail plans after spending $100m on studies
https://www.theguardian.com/australia-news/2023/mar/03/nsw-government-slams-brakes-on-high-speed-rail-plans-after-spending-100m-on-studies

While the McNaughton report has been kept secret by the NSW government, with Guardian Australia spending two years attempting to obtain the strategy under freedom of information laws, it is understood that early-stage pre-feasibility cases for all four corridors were conducted, with the Newcastle option emerging as a priority.

[ozbob]

^ was actually fast rail. In concert with some other fast rail lines.

The Albo mob are talking true HSR between Sydney and Newcastle.

[Beams Road Motorway]

The main beneficiaries of Sydney to Newcastle High Speed Rail will be rail freight, and north of Newcastle passengers, with the increased capacity. Even local services south of Newcastle could benefit, we'll just have to wait for the business case to know more.

Successive British governments made the mistake of touting speed over everything else, resulting in cutbacks and cost overruns. The government is potentially better off focusing on the wider community benefits then zooming in on speed. The Sydney-Newcastle congestion affects the XPT's starting time, so only building this leg could have a dramatic effect on the interstate service.

[SurfRail]

Worrying about what HSR will do to the XPT or CCN services is like worrying what cars will do to horses and drays.

[minbrisbane]

 

The ministers sentiment is where it's at.  If you're going to spend a metric ton of money, why not design and build true HSR?  Don't go in half measures meaning having to spend more money later. 

[ozbob]

Newcastle Herald --> Government forks out $78m on high-speed rail business case with route, cost $

The federal government will spend almost $80 million this year on a high-speed rail business case which will identify a proposed route and station locations between Newcastle and Sydney.

Infrastructure and Transport Minister Catherine King, whose government has faced pressure from the Opposition and Greens to get the massive project moving faster, announced on Tuesday that the High Speed Rail Authority would receive $78.8 million for an "initial" business case. ...

[ozbob]

The Guardian --> Australia to spend $80m on business case for Sydney-Newcastle high speed rail

The Albanese government will spend $80m developing a business case for the Sydney-to-Newcastle stretch of its east coast high speed rail line, as the decades-long project inches further forward.

The transport minister, Catherine King, said the allocation of $78.8m was part of Labor's $500m election commitment to the early stages of high speed rail, with the initial Sydney-Newcastle leg representing a "crucial waypoint" on the project.

The newly formed High Speed Rail Authority (HSRA) will deliver the business case to the government by the end of the year, and will determine a proposed alignment, station locations and the type of train sets to be used. ...

[ozbob]

Newcastle Herald --> Big questions need answering on road to high-speed rail $

The High Speed Rail Authority has a gargantuan task ahead in writing a business case for the Newcastle to Sydney bullet train by the end of the year.

The government announced this week that it would spend $78.8 million on an "initial" business case which would include a preferred route, station locations, costs and the type of trains to be used.

The 168 kilometres between the two cities pose a host of strategic, engineering, technical, operational and financial questions, not to mention political considerations leading up to the 2025 federal election.

A government study in 2013 proposed a route from Central Station proceeding under Sydney to Hornsby then underground again to the Hawkesbury River, onwards via tunnels and above-ground track to a new station at Tuggerah then across the Hunter River west of Newcastle.

It remains to be seen whether the HSRA business case will recommend something similar to the Albanese government or a high-speed line which integrates more closely with the existing rail network. ...

[Stillwater]

Maybe they can get their hands on a copy of the $100m NSW Government study. 

[#Metro]

The National Library will have to open a new section dedicated to just HSR studies.

 

[ozbob]

Roads & Infrastructure --> Gov seeking tenders for High Speed Rail

The Federal Government and High Speed Rail Authority are seeking tenders and experts to help develop and plan the first stage of the east coast high speed rail network.

The proposed section would connect Sydney, the Central Coast and Newcastle and represents the first priority under the newly formed High Speed Rail Authority, which will oversee the development of the eastern high-speed rail network.

The network could allow passengers to travel between major cities and regional centres at speeds exceeding 250 kilometres per hour.

The Government is seeking tenders for eight work packages that will support the delivery of a business case for the Sydney to Newcastle section of the high-speed rail network by the end of this year. ...

[ozbob]

Newcastle Herald --> High Speed Rail Authority pushes Broadmeadow station option $

The national authority working on bullet trains from Newcastle to Sydney has asked contractors to examine options for a new high-speed rail station at Broadmeadow.

The proposal marks a significant change in direction from a 2013 government study that suggested the high-speed rail route bypass Newcastle via a new station near Cameron Park.

The High Speed Rail Authority last week called for eight tenders to help develop a business case for the Sydney-to-Newcastle first stage of an east coast high-speed network.

Infrastructure Minister Catherine King has set an ambitious target of completing the business case by the end of the year, and the tender documents outline a rapid timeframe for identifying a preferred route, station locations, train types, operational requirements, costs, finance options and delivery strategies. ...

[Gazza]

An idea I have seen tossed about is a more French style approach where you have a HSR mainline following the M1, but for access to Newcastle a branch peels off around Wakefield / Fassifern and joins the conventional line at Glendale, and shares track for 12km to Broadmeadow.

Would probably make sense having the main HSR station there since its fairly central to the city, and you could then terminate all XPT services there. To support it, you'd want to extend the LR Broadmeadow along Tudor St.

[ozbob]

Newcastle Herald --> High Speed Rail Authority boss says Broadmeadow-Central line 'achievable' $

The head of the High Speed Rail Authority says building a bullet train from Newcastle to Sydney is a "once-in-a-generation opportunity" and he wants to "get it right" by making it attractive to as many people as possible.

HSRA chief executive Tim Parker confirmed he had asked potential planning consultants to look into new high-speed rail stations at Broadmeadow and Central in Sydney.

Mr Parker said running high-speed rail into the middle of cities like Sydney and Newcastle was "complicated" but "achievable".

"It's important we think about our customer base, make it an attractive service," he said.

"Part of it is not just about engineering convenience but where will passengers go.

"That's why it's absolutely warranted to look at Broadmeadow."

A 2013 federal government-commissioned study on high-speed rail recommended a route which skirted Newcastle to the west, but Mr Parker said times had changed. ...

[ozbob]

Newcastle Herald --> Tenders awarded for high-speed rail network business case $

The High Speed Rail Authority has awarded tenders for the development and planning of the high-speed train network from Newcastle to Sydney.

The federal government invited tenders for eight work packages, which will allow the authority to deliver a business case for the Sydney to Newcastle section of the high-speed rail network by the end of 2024.

The eight packages include project controls (costs, schedule and risk), rail operations planning, First Nations participation and engagement, and commercial, delivery strategy and industry engagement. ...

https://x.com/ozbob13/status/1801045172240765158

[ozbob]

https://minister.infrastructure.gov.au/c-king/media-release/world-leading-experts-board-high-speed-rail

World-leading experts on board for high-speed rail

The Hon Catherine King MP
Minister for Infrastructure, Transport, Regional Development and Local Government

13th June 2024

The High Speed Rail Authority (HSRA) is on track to deliver the first key milestone for Australia's first high speed rail line, with tenders awarded for the Sydney to Newcastle Business Case.

World-leading advisers will support HSRA to plan and develop the East Coast High Speed Rail Network, connecting Sydney, Central Coast and Newcastle.

A competitive open tender process sought industry experts with extensive experience in planning and delivering major infrastructure projects like high-speed rail.

Industry was also encouraged to form suitable consortia, where necessary, and comply with all requirements set out by the Commonwealth Approach to Market Terms.

More than 300 industry members participated in the HSRA's industry briefing held on 27 March, 2024.

The session was an opportunity for industry to learn more about the program's milestones and demonstrate interest in the project.

The eight work packages have been awarded to the following applicants:

Work packages    Advisers
Project Control Services (Costs, Schedule and Risks)   KPMG

Economics, Funding and Financing, Demand Modelling and Economic Development Strategy   EY

Commercial, Delivery Strategy and Industry Engagement   EY

Transport, Land Use and Property   WSP

Technical Advisory, Environment and Sustainability, Community and Stakeholder Engagement   
WSP and Arcadis

High Speed Rail Network Operations Planning   Arup

First Nations Participation and Engagement   GHD

First Nations Culture and Heritage   GHD

These advisers will bring a wealth of knowledge and experience to the program.

With 14.9 million passengers annually, Sydney to Newcastle is the busiest intercity rail line in Australia.

The business case will determine important elements of the network, including proposed corridor alignment, station locations, fleet, cost estimate and construction timeframes.

It will be an opportunity to benchmark best practice and explore lessons learnt from high-speed rail networks across the globe.

The Albanese Government has committed $500 million for the planning and corridor protection of the Sydney to Newcastle section, and established the High Speed Rail Authority to conduct the work independently.

HSRA will work closely with state, territory and local governments, industry and peak groups, community and First Nations stakeholders on business case development.

The first major milestone will be progressing with onsite studies like geotechnical investigations to test ground condition.

This will help inform high-speed rail corridor alignment and station locations.

The business case is expected to be presented to Government by the end of this year.

Stakeholders can register their details to participate in future engagement opportunities by emailing info@hsra.gov.au. 

Program information is available at www.hsra.gov.au.

[Gazza]

^Bob I'd be interested in registering as a stakeholder. I think we have a role to play, if nothing but to say "ensure what is built means that governments in the distant future can make use of this for a connection through to Qld.

[ozbob]

^Bob I'd be interested in registering as a stakeholder. I think we have a role to play, if nothing but to say "ensure what is built means that governments in the distant future can make use of this for a connection through to Qld.

Done 

[ozbob]

The Guardian --> Sydney to Melbourne in four hours: meet the man who seriously believes in high-speed rail for Australia

Sydney to Melbourne in four hours: meet the man who seriously believes in high-speed rail for Australia
Exclusive: Tim Parker has taken the reins of a project that has crushed the dreams of so many over the decades. But he insists it can become a reality

Given high-speed rail's much mocked history of failed starts in Australia, Tim Parker manages to appear optimistic, even excited, about the decades-long project he has been tasked with delivering.

Parker, a former senior executive at Sydney Metro, was in January appointed inaugural chief executive of the High Speed Rail Authority (HSRA) – the body established to carry out Labor's 2022 election commitment to build the rail line along the east coast.

Progress has been anything but high speed. It took until June 2023 for the authority to be created, while work on a business case for the initial Sydney-Newcastle section has only just begun. ....

[ozbob]

https://x.com/ozbob13/status/1805276009375338929

[ozbob]

Newcastle Herald --> Newcastle - Sydney high speed rail link a priority for engineering partners $

UK-based engineering firm Arup will partner with French based company SYSTRA to plan the proposed network operation of high-speed rail in Australia.

The contract for Network Rail Operations Planning was awarded to the Arup-led team in June after a competitive tender process by the High Speed Rail Authority, as part of their work to deliver the Sydney to Newcastle Business Case.

The partners' initial focus will be on the operations and maintenance requirements for the first stage between Sydney and Newcastle. ...

[ozbob]

Newcastle Herald --> High Speed Rail Authority drills under Newcastle as project builds steam $

The High Speed Rail Authority has started test-drilling 35 metres under Newcastle as it investigates how to build a bullet train to Sydney.

Authority chief executive Tim Parker is in Newcastle this week to inspect a drilling rig next to the existing heavy rail line at Broadmeadow and attend a briefing for the global high-speed rail industry on Tuesday.

Major international rail, infrastructure and design contractors Japan Railways, Siemens, Alstom, Hitachi, Hyundai Rotem, CPB and John Holland will be among about 350 industry representatives in Newcastle for the briefing.

Mr Parker said on Monday that the federal government could be ready to make an investment decision on the multibillion-dollar project by the end of next year. ...

https://x.com/ozbob13/status/1828092866868211728

[ozbob]

Government Statement

https://minister.infrastructure.gov.au/c-king/media-release/all-aboard-high-speed-rail-accelerates-first-investigation-works

All aboard as high-speed rail accelerates with first investigation works

Infrastructure, Transport, Regional Development and Local Government Minister Catherine King

26th August 2024

Nearly thirty boreholes being drilled in New South Wales will support critical geotechnical investigations required to determine the locations for the Albanese Government's High-Speed Rail between Sydney and Newcastle.

The geotechnical investigations are being undertaken by the High Speed Rail Authority (HSRA) as part of the business case being developed for the first stage linking Sydney and Newcastle.

High-speed rail will connect Australian regions, cities and communities – delivering more job and lifestyle choices, greater housing options and new economic opportunities.

We are planning for a high-speed rail network that will connect Brisbane, Sydney, Canberra, Melbourne and regional communities across the east coast of Australia.

The first stage will connect Newcastle to Sydney – a nationally significant corridor – to create a fast, reliable and regular link between the two largest cities in NSW.

Work has started on drilling 27 boreholes in key areas between Newcastle and Sydney to better understand geological conditions along the route. The information from this work will help in:

. determining the proposed depths of new rail tunnels;

. assessing geological and geotechnical conditions to cross the Hawkesbury River; and

. understanding the geological complexities of traversing the escarpment into the Central Coast and on to Newcastle.

We have committed $500 million for the planning and corridor protection of the Sydney to Newcastle section, and established the HSRA to conduct the work.

The business case for the Newcastle to Sydney stage is due to be delivered to the Government by the end of this year.

More information can be found at https://www.hsra.gov.au

[ozbob]

Facebook ...

Government Statement: All aboard as high-speed rail accelerates with first investigation...

Posted by RAIL - Back On Track on Monday 26 August 2024

[ozbob]

https://x.com/railbotforum/status/1828179731885514851

[aldonius]

My take here (fully due to e.g. zoomwhoosh over on SSC) is that the existing CCN track is so godawful and that the terrain is so challenging, that it costs ~the same amount of money to build fresh HSR as it does to incrementally upgrade to MSR.

(And of course if we ever want to see HSR north of Newcastle, then the route between Newcastle and Sydney has to be fast anyway.)

[ozbob]

Newcastle Herald --> Newcastle-Sydney high-speed rail possible by 2037 as tunnel plan emerges $

At least half the Newcastle-to-Sydney high-speed rail route will run underground, but the man in charge of the project says it can be built by 2037 if the government backs it.

High Speed Rail Authority chief executive Tim Parker told an industry briefing in Newcastle on Tuesday that about 50 to 60 per cent of the 165-kilometre line, or up to 100km, would be in tunnels.

The project would require 12 to 18 tunnel boring machines extracting about 10 million cubic metres of soil which could be used to "revitalise" former mine sites. ...

https://x.com/ozbob13/status/1828466825220542822

[timh]

My take here (fully due to e.g. zoomwhoosh over on SSC) is that the existing CCN track is so godawful and that the terrain is so challenging, that it costs ~the same amount of money to build fresh HSR as it does to incrementally upgrade to MSR.

(And of course if we ever want to see HSR north of Newcastle, then the route between Newcastle and Sydney has to be fast anyway.)

I vaguely recall a radio interview where one of the bigwigs involved in the project basically said exactly that, to some degree

[ozbob]

Newcastle Herald --> High-speed rail team must show how it can get passengers on board $

This week's high-speed rail industry briefing in Newcastle has answered some questions and posed a whole series of others about the Sydney bullet train.

High Speed Rail Authority chief executive Tim Parker and chair Jill Rossouw told industry leaders from around the world that a high-speed line could be finished by 2037 and that at least 50 per cent of the 165-kilometre route would travel underground.

The presentation laid out what seem to be emerging as parameters for the project: a one-hour travel-time between Broadmeadow and Central; one stop at Gosford and possibly another where Lake Macquarie meets the Central Coast; and a dedicated line running only 250km/h-plus high-speed trains.  ...

[ozbob]

https://x.com/ozbob13/status/1836138846880436714

[ozbob]

Sydney Morning Herald --> Why a Sydney-Newcastle high-speed train link would need some of the world's longest rail tunnels $

More than half of a 140-kilometre high-speed train line between Sydney and Newcastle would need to comprise tunnels because of hills, national park and built-up urban areas, resulting in the link having some of the world's longest rail tunnels if it becomes a reality.

Under the early scope for a dedicated high-speed link, up to 84 kilometres primarily between Gosford and central Sydney is set to comprise twin tunnels if the federal government makes an investment decision to proceed with the ambitious project as early as next year.

Underscoring the challenges, the longest of the continuous underground sections along the proposed route is set to be about 38 kilometres. In comparison, the Gotthard Base Tunnel under the Swiss Alps is the world's longest rail tunnel at 57 kilometres. ...