HE'S best known as a music entrepreneur and judge on TV's Pop Idol, but the great passion in Pete Waterman's life is something altogether different.

Waterman is a railway fanatic who, over the years, has invested millions of pounds into his hobby.

He's also a stamp collector, which made him the ideal person to launch the Royal Mail's latest special issue yesterday.

Classic steam locomotives are featured on the extra-wide stamps, which go on sale today.

Classic Locomotives, an anniversary issue, continues the transport series that began with buses in 2001.

The stamps also mark the 200th anniversary of the first journey by a steam locomotive, Trevithick's Penydarren, in February 1804, in Merthyr Tydfil.

At the national railway Museum in York, Waterman stood on the footplate of the GCR 8K 2-8-0, an express goods locomotive in British Railways livery, which features on one of the stamps.

Gavin Macrae, the Royal Mail's director of stamps and collectibles, said: "The association of steam and stamps goes back to the 1840s, which not only saw the introduction the Penny Black but also the arrival of the Steam Age, arguably the greatest achievement in transportation since the invention of the wheel."