Port Dargaville Rail and River currently has four carts doing the tours and another has been ordered, but there's plenty of scope for expansion, including the chance to more than double the length of the trip.
Kiwi Rail decommissioned the line about 19 months ago and Port Dargaville Rail and River director John Hansen said the company had been negotiating for the lease with the state entity for three years. Mr Hansen already operates Northern Wairoa River trips on the scow Daisy.
"We used to go past the rail lines while running the charter boat and saw the lines were not used, so thought of putting them to good use," he said.
"They're small but are still classified as rail vehicles. You can get a train ride (elsewhere) but here you take control of the rail vehicle."
He said the company was keen to extend its service to Waiotira, 32km southwest of Whangarei, which would be a 34km ride each way from Dargaville.
Mr Hansen said since they began in December, 318 people had gone on trips and most were from outside Northland.
"Weekends are busy. During weekdays, our busiest is usually the middle of the week. Seventy per cent of our clients are from outside the district - Whangarei, Auckland and Wellington," he said.
"Twenty per cent are from overseas who book and find out about the trips through the local information centre. We've had clients from England and Canada."
Similar rail carts are also run in Rotorua, New Plymouth and Whakatane.
John Hunter and Bruce Jackson from the Glenbrook Vintage Railway in South Auckland took to the rail carts this week and gave them a thumbs-up.
"This is going to be marvellous. I'd like to see more carts so we can bring more people in coaches," Mr Hunter said.
Mr Jackson runs steam trains from Glenbrook to Waiuku, and brought a Silverfern rail cart from Auckland to Whangarei last year.
Those wishing to ride the rail carts can book through www.portdargavillecruises.co.nz.
