The public is being offered the chance to step back in time and take a ride in a 55-year-old railcar, as part of today's 150th anniversary celebrations of rail to Port Adelaide.

A 1950s Red Hen railcar will travel between Adelaide and the Port and the public will be able to see displays of the SteamRanger and Pichi Richi rail services.

The railway was the first government-built and owned steam line in the British Empire and paved the way for an extensive railway to be built around the state.

National Railway Museum manager Des Egan says the merging of old and new technology through the Red Hens today will be particularly exciting.

"They're running on a bio blend of fuel from South Australian farmers and they're running shuttle trips from the museum to Woodville from one o'clock in the afternoon until four o'clock in the afternoon, so that's open to the general public."

He says the rail line has great historical significance.

"It was the first steam-operated and government-owned railway in the British Empire at the time and also more importantly for South Australia, it was the beginning of an extensive railway network around South Australia to bring produce and industry products into the Port," he said.

ABC Online