Their appeal lies much more widely than just among men of a certain age with model railways in their attics, but to all ages and genders.
It’s a combination of the evocation of yesteryear, to the so-called “good old days” of the railways’ supposed “heyday”, and the fond belief that steam engines are like living, breathing creatures, blasting out smoke and steam.
The Jacobite train service on the West Highland Line is the nearest thing, outside theme parks, to the world of Harry Potter come alive, attracting legions of fans not only to book seats aboard but gawp at spectacular vantage points like the Glenfinnan Viaduct.
There’s also plenty of steam off the main lines, but to travel on a heritage railway is an “experience” many of us have long missed because of Covid lockdowns and travel restrictions.
As a spur to encourage visitors’ return, Britain’s historic lines and railway museums this week launched a “Love Your Railway” campaign to heighten awareness of what they have to offer.
Led by Britain’s most popular, the North Yorkshire Moors Railway – of Channel 5 fame – the initiative also seeks to highlight the railways’ key roles such as in providing skilled work and training, conservation and research, and also how they have been drastically hit by the loss of income from the pandemic.
Among the dozen or so lines north of the Border, I have been astounded at the scale of the Scottish Railway Preservation Trust’s (SRPS) engineering operations at its Bo’ness centre, with its complex of engine sheds and huge and varied fleet of locomotives and carriages.
It also has many charismatic champions, like chairman Steve Humphreys, whose description of the 40-year-old organisation being in the business of “making memories” for visitors immediately caught my imagination during a visit two years ago.
His words then should now be a clarion call at a time when such enterprises have never been in greater need: “The SRPS was formed in 1961 by far-sighted people who saw the railways were changing rapidly.
"We want more people to become engaged with Scottish rail history, which was central to the country’s industrial development.”
Other signatories to the campaign in Scotland are the Keith & Dufftown Railway in the north east, and the Lathalmond Railway Museum near Dunfermline.
But the star attraction this week – by apparently lucky coincidence – was the Strathspey Railway in the Cairngorms, which staged the landmark unveiling, after a £520,000 restoration, of one of its original locomotives that has lain dormant for nearly 30 years.
As it emerged resplendently overhauled from a shed on Tuesday, the 1934 “Black Five” engine LMS 5025 turned heads both in Aviemore and on Twitter with admiring comments such as “superb job”, “stunning restoration” and “fantastic sight and sound”.
The locomotive is due to be back in passenger service next week – and what a draw it will be.
The 5025 will hopefully symbolise the confidence, optimism – and determination – of the many dedicated volunteers and staff in the heritage railway sector that there continues to be a future in the keeping the past alive.