The Big Yin became the Big Gaffer as Billy Connolly made a surprise visit to an East End training academy.

That unmistakable voice commanded the attention of dozens of star-struck apprentices: “Get back to work,” he bellowed jokingly on walking through the doors of City Building’s training centre in Queenslie, before spending two hours chatting with staff and some of its 500 trainees.

The impromptu tour was a trip down memory lane for the 67-year-old funnyman, who famously served his time in a five-year welding apprenticeship in the Clyde shipyards.

He said: “It’s brilliant mixing with apprentices again. We had the best tradesmen in the world and I was lucky enough to know some of them when I was a kid on the shipyards. I must say I really enjoyed being a tradesman.

“That’s what Scotland was famous for: building beautiful ships and houses and bridges.”

The Anderston-born, New York-based comic was in town to spend time with his family after completing a month-long residency at London’s Hammersmith Apollo.

He revealed he had to turn down a part in Glasgow-set film The Last Word with Ewan McGregor as it clashed with his sold-out, 10-night run at the Clyde Auditorium last October.

Last week, Connolly, who also has a home in Aberdeenshire, opened the salmon season on the River Dee by swapping the traditional whisky toast for Irn-Bru. A star of The X Files: I Want To Believe, The Last Samurai and Oscar-winning film Mrs Brown, he will return to the big screen as the King of Lilliputia in Christmas blockbuster Gulliver’s Travels. Connolly congratulated three young trainees, who have been shortlisted for Apprentice of the Year at this year’s APSE (Association for Public Service Excellence) awards.

Apprentice joiner Ronson Slater, 20, from Shettleston, electrician Shaun Lafferty, 21, from Easterhouse, and Parkhead plumber Nicolle Wright, 19, will compete with 21 nominees at the ceremony at Peebles Hydro Hotel on February 18.

It was Nicolle and her female peers who most impressed Scotland’s best-known comedian.

Connolly exclaimed: “I don’t remember any women! They’re extremely good at it, of course, and there’s no reason why they shouldn’t be, but when I was a kid it was a very male affair.”

Third-year apprentice Ronson added: “Me and my cousin went to his show in Glasgow just before Christmas and we couldn’t believe we were so close to Billy Connolly then and now he’s here. It’s a wee bit surreal.”