Picture this: you are sipping a martini in a sumptuously decorated room where the light from Robert Kime lamps glints off oak-panelled walls. The scent of cigar smoke wafts in from a balcony while dinner awaits next door. A Thursday night at 5 Hertford Street? The evening after a shoot? No – you’re on a train hurtling across the moors.

This is what it feels like to own a private train. Before the jet age, having one’s own train was the for billionaires. JP Morgan’s preferred mode of was his Pullman railcar.

Bessie Smith, the Beyoncé of the 1920s, travelled around America in a custom-made railroad car – essentially a two- storey speakeasy with bedrooms, bathroom and kitchen – that was a rolling centre of the debauchery that made up the blues scene. In recent decades, the private train has rather disappeared from the billionaire’s toy box, but now it is making a comeback. The newest, The Chairman’s Set, is in Britain and has its own steam engine.

Millionaire businessman Jeremy Hosking began work on his train seven years ago, enlisting the help of -based designer Sara Oliver and Independent Rail. Now this fabulous steamer whizzes through Scottish stations en route to his home, where he has had his own track built. Amazingly, the train is allowed to travel anywhere on the British network, although because steam trains are no longer permitted to run in , a small concession has to be made and it switches to diesel.

What Oliver and her team have created is nothing .