Passengers on both the Tranz Alpine and the visiting Silver Fern railcar faced travel disruptions today after a derailment at Omoto early this morning.

Two wagons slipped off the rails at the entrance to Greymouth, near the old Omoto slip, about 5.30am, ending up near the Cobden rail bridge.

Kiwi Rail manager West Coast Chris Stoop said both wagons were on the back of a train pulling 26 wagons.

Stoop said the train driver was travelling at a low speed at the time and because of that he was not aware that the wagons had derailed.

"It was not until he came to two sets of lines that he realised something was amiss, and the two wagons took separate routes. The wagons came to rest about 800m from where they initially derailed."

One wagon was empty and the other loaded with wooden pallets.

The train was also carrying a hazardous substance, chlorite solution, so the Greymouth
Volunteer Fire Brigade was called as a precaution. However, the hazardous substance, destined for Westland Milk Products in Hokitika, was in the wagon immediately behind the locomotive and was not in danger.

The derailment had delayed the departure of the rail enthusiasts excursion on the Silver Fern, and the Tranz Alpine, which was due in Greymouth about lunchtime.

Passengers were dropped off at Stillwater and bused to the railway station. A crane was brought in to lift the two wagons off the line early this afternoon.

- Greymouth Star