IT’s a sight to quicken the heart of every railway fan – two legends of the track sitting side-by-side in a scene not witnessed for many a decade.

World steam speed record holder Mallard, arguably one of the most famous locos in the world, was yesterday (May 30) re-united with its sister engine, the mighty Dominion of Canada.

The gleaming machines met at the National Railway Museum in York in preparation for this summer’s 75th anniversary celebrations of Mallard’s now-legendary 126mph run.

And at an historic “Great Gathering” on July 3 they will be joined by the four other surviving A4s from the golden age of steam.

Dominion of Canada was repatriated from Montreal on a two-year loan specifically for the anniversary and the museum’s team at Shildon in County Durham have painstakingly given it a Mallard-style makeover.

The museum’s associate curator Bob Gwynne said: “It’s been a real labour of love to transform Dominion of Canada from its sixties BR green livery into glorious garter blue - just as it was in its 1930s heyday.

“The stage is now set for our showcase of all six survivors of the A4 class in our Great Gathering, and we can’t wait .

“We think it’s fantastic that people from all over the world, including the US, Canada and Australia are travelling to York to join us in marking the milestone in global history that is Mallard’s world record-breaking run.”

He added: “I don’t think we’ll see this again. It’s a once-in-a-lifetime thing and whether you like trains or not, you have to admire these great machines.”

Thirty five A4 locomotives were built in Doncaster after LNER decided to roll out a high speed, inter-city train service.

Despite its name, the Dominion of Canada never actually served in North America - it spent its working life as a high-speed service on the mainline between London and Edinburgh.

It was originally called the Woodcock, but its name was changed to reflect Britain’s Commonwealth and international interests when the railways were nationalised.

On its retirement it was restored in Britain 1967 and sent to Canada as a museum piece.

The Great Gathering tales place from July 3 to 17 and Dominion of Canada can be seen in the museum in the run-up to the event.