Terrace Tunnel Upgrade entering new phase


Driving conditions in the Terrace Tunnel have changed as initial preparations required for its upgrade are nearly complete and more physical work begins.

The $50 million upgrade is moving on to the next phase which involves demolition work within the tunnel and the start of construction on the new control buildings at the south and north portals. 

NZTA Acting State Highways Manager Craig Nicholson says that as the first step in this process they have re-marked the lanes and are erecting concrete barriers within the tunnel to provide a safe working area. 

“The new line markings have been laid and now driving conditions inside the tunnel have changed - road lanes are narrower, the speed limit is 60 km/h and lighting is dimmer,” says Mr Nicholson.

He says that concrete barriers have been placed inside the tunnel.
“Now that the barriers are in place, demolition of the existing ceiling within the tunnel can start but to gain access to this ceiling, and provide a work platform, we will use a large steel gantry which will also act as a false ceiling.”

The purpose built 11m wide, 10m long gantry weighs approximately 22 tonnes and will be moved along the interior of the tunnel as work progresses. The bright orange structure can be lowered to 2.5m when contractors are using it as a work platform but will sit 5m off the road surface during the day when the tunnel is open to traffic. The gantry was installed last week.