NEW ZEALAND: KiwiRail has completed a two-year project to realign a section of its Christchurch – Picton main line on South Island to bypass the line’s oldest tunnel which had been damaged by an earthquake.
Opened for rail traffic on May 25, the 1 km bypass around the 108-year-old Tar Barrel Tunnel forms part of a 4½ year programme of repairs to the line following the 2016 Kaikōura earthquake. Although the damaged tunnel had been temporarily repaired, it was not up to modern standards and the restricted width imposed operational constraints on KiwiRail freight trains including a permanent speed restriction.
Working with Waka Kotahi NZTA, KiwiRail and contractors Tonkin + Taylor and HEB Construction have built 1 km of new line and the Ruakanakana Overpass which was completed in November to carry State Highway One. The new alignment to the east of the old tunnel required the excavation of around 450 000 m3 of rock and soil, some of which is being used to backfill and seal the damaged bore.
‘With funding from the government, we’ve been able to remove the tunnel from the route altogether, which is great news for our freight customers around the country’, said KiwiRail Group Chief Executive Greg Miller. ‘The new link strengthens the road and rail connection for the Marlborough region and New Zealand’s transport network. Building seismic resilience into our core freight routes is vital to ensure we can manage if there is another significant earthquake.’
