The 12-day project took place last year and was filmed for a series by Channel 4, with the first of five episodes of The Biggest Little Railway in the World airing on Sunday night.
Presenter Dick Strawbridge said it was a typically bonkers British idea, albeit a simple one.
'It’s a very simple idea. The Victorians failed to build a railway along the Great Glen Way and it was one part of the railway network in Scotland that was never built,' explained Dick.
'So we had the idea of building a model railway across Scotland. It just had to be done. So we did it, along the Great Glen Way.
'Model railway enthusiasts are a very maligned bunch. People don’t understand them, but it was a great opportunity to get a bunch of like-minded people together.'
The former army officer turned television presenter and author, admitted it was a tough challenge, even for him: 'Scotland in June is not like Scotland in January, but it’s still pretty challenging. We were eaten by midges, the weather changed every day, we had sunshine, wind, rain, fog, and it was the most amazing place – so beautiful.'
The 56-strong team of enthusiasts was brought together via a nationwide call for volunteers issued to model railway groups.
'We also looked for grown up engineering jobs, not in an age sense but in terms of size. And we auditioned them, we gave them challenges to see what skills people had,' said Dick.
'They all did something that very few of them ever thought they could do, because we must have walked hundreds of miles each. By the end, we knew the Great Glen Way very well.'
Dick says, in terms of scale, the project equated to constructing half of the trans-Siberian railway in 12 days.
'And some of the hills we had to go over were pretty tall. One of them was the equivalent of one-and-a-half Everests.
'And Silver Lady, our little steam engine, was meant to pootle around on nice level ground, with the occasional very gentle incline of a couple of degrees. She was not built to cross Scotland. That, in its own right, was one of the big challenges. One coast to the other is a long way for a little engine.'
Asked what was the biggest obstacles that had to be overcome, Dick singled out Scotland's most infamous airborne irritant.
'Midges. I think this year in Scotland there was an increase in the midge population of 50 per cent. There were something like 49 billion extra midges.
'We had mountains. We crossed the Caledonian Canal. One of the bridges we built looked a bit like the bridge over the River Kwai. That was a phenomenal thing. Alec Guinness would have been happy if he’d seen it.
'But those obstacles were not as difficult as the physical obstacle of getting the job done, because it’s relentless. The number of miles, every day, that had to be done, and the number of pieces of track required, it was so tough.
'We were having to wear nets because of the midges, and we’d have to walk two miles in because there was no road access, carrying all the track. But one thing I did like is that people got to appreciate how beautiful that part of Scotland is.'
But Dick admitted the sense of achievement felt by everyone involved at the project's conclusion made it all worthwhile.
'When you work with people, you buy into it, you work together and you pull together. It doesn’t matter what your challenge is, there’s a sense of achievement at the end of it.
'And you see real camaraderie. About halfway through, I forgot I was presenting a TV programme. As far as I was concerned, there was a bunch of us who were going to do something silly, and we were going to do it together. I talk fondly about it because it was amazing. And the people were amazing. '
*Episode 2 of The Biggest Little Railway in the World is on Sunday, January 14, at 8pm on Channel 4.
Yes! I would like to be sent emails from West Coast Today
I understand that my personal information will not be shared with any third parties, and will only be used to provide me with useful targeted articles as indicated.
I'm also aware that I can un-subscribe at any point either from each email notification or on My Account screen.