Kaimai Tunnel project on track

23 October 2015 1:01PM

Kaimai Tunnel works are well underway. The project team led by Project Manager Neil Mason and Construction Manager Tevita Brugger have already completed repairs on more than 300 metres of concrete slab and completed cleaning on 5.1km of the 8.8km tunnel.

Tevita says the material developed to undertake repairs is very special because it is strong enough to run trains on after 90 minutes, is not flammable and does not give off any harmful gasses. “We still have 350 metres of concrete to do and expect to have it finished by Christmas.

“The project work is starting to show some effect. As a direct result of the work that has been done the line returned to its 80km/h speed for the first time in four years.”

Over a 48-hour line closure in September, the team installed a special slot drain into the floor of the tunnel. “The drain will be used to intercept water running underneath the tunnel.

These water volumes were encountered when the tunnel was built but are not well understood. We need to control the water and to do this we need to determine the size of the pipe. The slot drain will allow us to observe the water flowing freely,” says Tevita.

“Next year, we’ll start construction on the new leaky feeder radio system followed by a new phone system.”

Tevita says further investigation into water pressure and flows in and around the tunnel will help determine the scope of the project, which could take 5-10 years.

“Most projects would involve 5-6 days of work on-site per week, whereas we only have access to the tunnel once a week and the rest of the time it remains open, due to high volumes of trains. On top of that, we are working in a 9km-long tunnel with a single track, with crews who do not live around the area.

“Kaimai is a complex and challenging project and this means that to maximise our production time requires a higher degree of planning and coordination is required."

Media contact: 04 498 2038