Melbourne Rail Link

The Melbourne Rail Link was a proposed twin 6 to 7 kilometre (3.72 to 4.34 mi) rail tunnels between Southern Cross and South Yarra with four new underground stations at South Yarra, Domain and Fishermans Bend (Montague) and Southern Cross Station. The tunnel would have connected the Belgrave, Lilydale and Alamein lines with the Frankston line enabling the operational separation of various existing lines on Melbourne's rail network and increase the capacity of the system to metro-style frequencies. Following a change in State Government due to the state election, the project was cancelled and the previous Metro Tunnel proposal was reinstated.

Tunnel data from Wikidata (CC0). Summary from Wikipedia (CC BY-SA).