A trip on the country's scenic TranzAlpine train took a turn for the worse when it hit a slip yesterday afternoon.

The train traveling from Christchurch to Greymouth struck the slip near Dobson, not far from the old Brunner Mine site at about 1pm.

The slip was caused by a deluge of heavy rain following a cold snap that made its way across the country over the weekend.

About 20 KiwiRail staff are on site this morning.

Executive general manager operations Paul Ashton said none of the 85 passengers or five crew on board were injured.

The carriages were towed back to Moana where passengers were transferred to buses and taken to Greymouth.

Their return journey to Christchurch has been replaced with buses.

Rob was waiting for the train but found himself on a bus with the other passengers after it hit the slip.

He said a few of them seemed shaken up and said they had been thrown around.

"They said it was a sudden jolt. the driver hit the brakes hard and they didn't know they had hit a slip.

"The impact was right at the front of the train."

Rob said the staff on board the train were "absolutely phenomenal" in dealing with the situation.

Moana resident Sarah Hammond said she was out walking her dog yesterday when she came across a group of people who said they had traveled by train on Sunday and were staying the night in Moana.

"They said there had been a slip and the train was running late and they were just waiting to see it come back in."

Hammond said she was told some of the train carriages had been damaged in the incident.