IT'S RARE to see two children with smiles on their faces after they've been handed a piece of coal, but brothers Luke and Henry Young beamed as they showed off their gifts.

"I've just been given a piece of coal," Luke said.

"And I've just seen the inside of a train.

"It's the first time I've seen a steam train and it's really exciting."

The boys travelled from Oakey with their parents for Jumpers and Jazz, and sights set on seeing the steam engine leave the platform.

A case of right place at the right time saw the boys hoisted up on the the steam engine's front compartment, where they were given the exciting experience of seeing the inner workings of the train.

"There was this big part for the coal, and that's shovelled into the fire pit," Luke said.

Little did the brothers know just how lucky there were to set eyes on the train at all.

The Southern Downs Railway trip to Hendon very nearly didn't happen, but with a few helping hands, and a special arrangement from Queensland Rail ensuring it chugged out of Warwick on time.

The coal-covered team at Warwick's Southern Downs Steam Railway were considering cancelling their weekend heritage train trips due to long-running repairs being carried out on the C-17 steam locomotive.

Then Queensland Rail came to the rescue, leasing one of its steam locomotives to SDSR for three months.

The trip to Hendon proved one of the most popular events of this year's Jumpers and Jazz, both the 11am and 2pm trips to Hendon selling out.

"We've got full carriages for this trip, and we did for the one in the morning," SDSR secretary Bob Amos said.

"That's about 120 people.

"We had a lot of walk-ons... people who didn't book.

"They must have been here for Jumpers and Jazz, and seen us in the program and come along."

Mr Amos noted along the way they expected to see plenty of trainspotters, out to get the perfect photo of the rare locomotive.

"They always have their interesting spots," he said.

"They get on top of bridges, near gullies and on the sides of cliffs."

Mr Amos reiterated how thankful the group was to Queensland Rail for leasing the train, which is the exact same make and model of group's C-17, for such a short term.

"Queensland Rail have been very good," he said.