A heritage railway turntable at Goulburn is spinning once more, after a derailed train caused massive damage to the 80-year-old structure in 2013.

The turntable had been out of commission for over two years, after a derailed train was pushed onto the turntable, spilling 90 tonnes of canola into its pit.

Dale Wake, president of the Goulburn Locomotive Roundhouse Preservation Society, said the crash caused extensive damage to the turntable.

"Some Queensland rail operator pushed a train in here that they shouldn't have," he said.

"There was probably 90 tonnes of canola in that pit at one stage.

"The lasting damage was that one third of the turntable, we couldn't use."

Despite a push to have the turntable restored, repair work did not begin until late last year.

"The funds were there … it was the regulators and whatnot that we had to persist with," Mr Wake said.

He said his society would now be able to operate the turntable to raise money.

"We can now create a bit more finance, through turning bits and pieces," Mr Wake said.

Andrew Gordon and his son William work on restoring carriages together. ( ABC News: Alexandra Beech )

Open day brings out rail enthusiasts big and small

An open day held to celebrate the turntable's restoration was attended by train enthusiasts young and old.

Andrew Gordon said restoring vintage trains had been a passion of his for years.

"I've loved trains since I can remember … hauling a wooden carriage around on the ground," he said.

"It was just watching them all get scrapped."

Mr Gordon said he had restored several carriages with the help of his son William.

"You could buy them for a couple of hundred dollars, it was easy — and that was delivered," he said.

"If they knew you were going to preserve it, then there were no problems at all."

Young locomotive fan Xavier Alling said it was exciting to be able to explore old trains at the roundhouse.

"Going under them was really cool, to see all the brakes and all that, it was really cool," he said.

His brother Caelan said he was excited to learn about how the trains worked.

"I pretty much like how all the pistons and things work, I find that cool," he said.