Details of underground rail loop hubs revealed

Details of the Suburban Rail Loop’s six underground hubs have been revealed, with the tunnel reaching its deepest point near Box Hill.

The refined Suburban Rail Loop tunnelling profile reveals the detailed underground path Suburban Rail Loop East will follow through Melbourne’s middle suburbs.

Train passengers travelling between Cheltenham and Box Hill on the $34.5bn Suburban Rail Loop would be about 60m below ground at one point of the journey.

But the six stations to be built as part of the mega-project would be 16 to 24m beneath the surface, in a bid to reduce the time it takes passengers to emerge at street-level.

That depth is shallower than stations along the City Loop.

A refined route for the SRL Stage One project, which is set to start construction next year, is being released this week showing details of six underground rail hubs.

Monash station — which is near to the university in Clayton — will have the deepest position at 24m below the surface, while Box Hill will be close behind at 23m.

The start of the tunnel, next to Southland shopping centre in Cheltenham, will be the nearest the surface, before trains dive to their deepest point of the journey.

Details have been revealed about the six underground rail hubs.

New modelling shows the tunnel will plunge 60m below ground near Box Hill.

More than 10km has been drilled so far to test the complex and varying topography across Melbourne’s southeast and east, while laser scanners have been used to create 3D models of basement car parks below Box Hill high rises.

Seismic testing has been used by engineers at Box Hill to also test how vibration travels through the ground.

Executive general manager rail and infrastructure at the Suburban Rail Loop Authority, Nicole Stoddart, said the priority was to create a more seamless transfer for passengers.

“There are a host of technical and geological requirements to consider, but we also want to create the best possible experience for passengers, by locating the stations as close to the surface as possible,” she said.

“It is a highly complex task tunnelling underneath Melbourne’s middle suburbs. We have to take into account ground conditions, existing infrastructure, and gradients of the track to allow trains to travel at speed.”

The length of the first stage of the project is 26km, while the second stage — called SRL North and set to run between Box Hill and Tullamarine — is about 34km.

An investment case was recently revealed for the combined east and north sections of the project, with the government saying there was a positive benefit-cost ratio for the city-shaping line.

Suburban Rail Loop Minister Jacinta Allan said at the time that the first stage of the line should be opened by 2035 when 71,000 people a day would use the service.