Almost 700 of his mementos from NSW and the ACT's rail history, including parts of engines, signs, signals and timetables, were taken off the sidings and put under the hammer at auctions in Fyshwick on Saturday and Sunday.

Both floors of Ardent Auctions were filled with the equipment, which ranged from cast-iron practical equipment to old maps, station seats and highlighted routes.

Mr Snelson has retained his favourite parts of the collection, but the decision to auction off most of the items came from a desire to help his daughters get deposits on houses.

"They're battling to get into the housing market, and I'm 70 now," he said.

"I'm having my deceased estate auction now, while I'm still alive, so I can say where it goes to. Hopefully it raises a bit of money to get them a deposit."

Mr Snelson's collection started on his 40th birthday, when he was given a Silverton Tramway sign.

Since then he has amassed hundreds of objects through forensic searches through scrap metal yards, antique shops, private collections, swap and sell pages and weekend markets.

Some of the pieces were bought from yards as old steam and diesel engines were pulled apart at scrap yards.

"You couldn't do that any more, too many problems with OH&S," Mr Snelson said.

Many of his discoveries in the early years of the collection are now hard to find, which he hopes will help attract enthusiasts.

Most were originals, though Mr Snelson said he had redecorated or touched up some of the items on display.

The collection eventually filled up Mr Snelson's garage to the point where he "couldn't move", but he intends to keep finding objects beyond the auction.

"It's been fun, I've enjoyed every moment of it and I'll still be going to markets and swap meets," he said.

"The Queanbeyan swap meet's on next weekend, I'll be going to that."

Auctioneer Gary Skewes said the collection was "an amazing accumulation rarely seen outside of a museum collection".

The auction will continue on Sunday at Ardent Auctions, 3 Wiluna Street, Fyshwick.