SH1, railway near Kaikoura closed until Thursday at best

State Highway 1 and the railway line near Kaikoura will remain closed until at least Thursday, as contractors work to clear 20,000 cubic metres of rock, dirt and debris dumped across the road and railway by a massive slip on Friday night.

The 100-metre long slip at Peketa, about 8km south of Kaikoura, is the biggest ever seen on that stretch of SH1, the New Zealand Transport Agency (NZTA) says. It is blocking vital supplies and equipment to help rebuild earthquake-stricken Canterbury.

Contractors have been on the job since early this morning, trying to clear the debris so supplies can get through, but Canterbury State Highways Operations Manager Peter Connors said they must be confident there is no risk to road users before re-opening the highway. 

NZTA was also monitoring the hazards to workers trying to clear the slip.

Heavy rainfall, and not recent earthquake activity, is being blamed for the slip. 

Cars are being diverted to the inland Kaikoura Road, which will add an extra 90 minutes to the journey to Christchurch. Trucks, buses and heavy vehicles must use SH63 via the Wairau Valley and SH7 via the Lewis Pass to travel south, adding another two-and-a-half hours to a trip to Christchurch.

KiwiRail confirmed the TranzCoastal passenger train service between Christchurch and Picton would also be closed until at least Thursday. It was unable to provide a bus replacement due to the slip.

``We apologise for the disruption to our customers but as the road is closed as well we cannot run a coach replacement and hope to keep even remotely to timetable or meet the Interislander ferry,'' spokeswoman Deborah Hume said.

In the meantime, KiwiRail was contacting passengers to offer them alternative dates or a refund.

She said the TranzAlpine, which runs daily between Christchurch and Greymouth was unaffected.