New Zealand’s Department of Conservation is mulling a proposal by Milford Sound Link Rail (MSRL) for a 13.5km long tunnel under the Humboldt Mountains in the Fiordland National Park on the South Island.

MSRL has applied for a land use concession to build and operate the single bore, single-track rail tunnel, which would run from Routeburn to Hollyford Valley. The tunnel is part of a larger transport scheme that would shorten the distance between Queenstown and Milford Sound by 60% from 304km to 121km.

The company hopes that work on the tunnel could start in 2012 or 2013 to get the rail link operational by 2015. Trains operating in the tunnel would haul roll-on/roll-off carriages for buses, cars and other vehicles.

Routeburn portal would be on private land and even though the Hollyford portal would be built on Crown land, at Gunns Camp in the national park, MSRL believes the challenge of getting approvals was not insurmountable.

No details of the cost of the tunnel have been released, although a proposal for a shorter, 10.2km long, bus tunnel was estimated to cost NZ$150M (US$119M). If the rail tunnel is approved then the plan for a bus tunnel, put forward by the Milford Dart Company, would either have to be scrapped or amended because a previous plan was stopped when the Department of Conservation refused to change the area’s management plan.