Tunnelling work has begun below St Helena Road as part of the Tintenbar to Ewingsdale Pacific Highway upgrade. 

Federal Minister for Infrastructure and Transport, Anthony Albanese said the tunnels will measure 434 metres long, 19 metres wide and will be approximately 46 metres below St Helena Road.
“The tunnelling is expected to take 10-12 months and when complete in 2014, will accommodate three lanes of traffic in each direction,” he said.
“In the coming days, workers will begin excavating the tunnel using drill and controlled blast methods to get through the strong basalt rock. This is state of the art technology which will help break though rock that is believed to have originated from lava flows from a volcano centred on Mount Warning roughly 23 million years ago.”
NSW Minister for Roads and Ports, Duncan Gay, said the tunnel will be temporarily supported with steel rock bolts and reinforced concrete to provide a safe working environment for tunnel workers.
“The tunnels will require 30,000 cubic metres of permanent concrete, more than 40,000 square metres of waterproofing membrane, contain more than 3000 steel rock bolts, and have 32 reversible jet fans for ventilation and 2.4 million litres of water stored in tanks to supply the tunnel’s fire deluge system,” he said.
“Safety features of the tunnels will include three emergency exit cross passages between the twin tunnels, an automatic fire deluge system, a ventilation system and air quality monitors.”
The Tintenbar to Ewingsdale Pacific Highway upgrade will reduce travel times, freight transport costs and boost safety for the 12,500 motorists and truck drivers that use this section of road each and every day.
Jointly funded by the Federal and NSW Governments, the upgrade is expected to be completed in the second half of next year.
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St Helena Tunnel Blast Video