More than 800 people climbed aboard a grand old train visiting on Saturday and about 1000 people were expected on Sunday, organisers reported.

The Beyer-Garratt 6029, the largest operating locomotive in the southern hemisphere, was brought to Dubbo by the Canberra Railway Museum and attracted a crowd of all ages to the city's railway station.

"The sun's out and the trains are already 80 per cent full, so it's going to be a big day for us," Canberra Railway Museum operations manager Les Coulton said on Sunday.

Mr Coulton, a steam train driver, said the Dubbo Steam Shuttles had attracted attention during return trips to Geurie and to Mogriguy.

"We love bringing the steam trains to regional NSW and love the look of all the kids faces as they ride along on the trains listening to the sounds, it's brilliant," he said.

"You get the kids who are into the Thomas and Chuggington sort of things.

"And you get the old people who used to travel by steam trains all the time.

"They wouldn't actually have gotten the chance to travel behind a Garratt locomotive on passenger services up here back in the day... Garratts were normally on heavy goods trains around here.

"(There's been) cars for miles and miles we've seen, taking photos and reminiscing about days gone by."

The Stewart family took seats in a carriage on Sunday after going "trainspotting" on Saturday.

Twins Madelyn and Darcy Stewart, 4, had enjoyed waving to all the people, while dad Bradley said there was a good aspect as they travelled towards Wellington.

It had been lovely and lots of fun, mum Michelle Stewart said.

Three-year-old Remy Sharkey loved Thomas and all sorts of trains, grandmother Pam Sharkey said, as they arrived on the platform.

Ross Graham was at the station with his camera.

"I remember these when I was boy," he said.

"I used to see the trains go to Sydney, and also on the Molong line.

"It brings back memories."