Leyland Roadtrain Cabriolet

"Look up…way up…" is how The Friendly Giant introduced himself to me and countless other children as we sat down to enjoy the exploits of the giant, a rooster, and a giraffe. It was a novel way to start a TV show, and a memory that came flooding back as I sat down to write about the friendly giant of semi trucks, the glorious Leyland Roadtrain Cabriolet.

It is what you think it is: a convertible truck. But unlike those official factory efforts from Dodge (Dakota Convertible) and Chevrolet (SSR), Leyland is a heavy truck manufacturer, and, as you can see, turned one of their big trucks into the ultimate summer cruiser for those who laugh in the face of low bridges.

Introduced in 1980, the Roadtrain range of heavy trucks was Leyland's way to simplify their range by producing one basic heavy truck design to suit nearly any job thrown at it. It was also one of the last real Leyland models made before the British marque was acquired by DAF in 1990. Today, Roadtrain models are scarce, owing to the rough lives they lived but also because rust is an issue for the model, apparently finding the cab an easy target for corrosion.

Anyway, by 1985, Leyland thought it'd be important to build something new and exciting in order to get companies excited about the Roadtrain. It'd been on sale for six years; so what would make an operator look twice as a Roadtrain drove by?

I love loopholes, and Leyland exploited a rather large one: in the UK, if a heavy truck has all of its towing equipment removed, it's classified not as a tractor or large truck—but as a "heavy motor car" and can be driven by anyone with a normal driver's license!

Neat, eh?

Thanks to a period road test by Motor magazine, I can also tell you that it's the only car in the world powered by a 12.2-litre Rolls-Royce designed and Perkins built inline-6 cylinder turbodiesel engine with 337 horsepower and 1062 lb-ft of torque—just 32 lb-ft shy of what you'd get from a Bugatti Veyron Grand Sport Vitesse.

With brisk performance considering its weight, the Roadtrain Cabriolet wouldn't have been an enjoyable way to whip around your favourite road—thoughI think that trees, narrow lanes, and a bazillion gears to shift would kill any Andretti-like adventures. Besides: ten forward gears from the constant mesh transmission would be a nightmare to a non-expert trucker.

Driven around shows during its time as a promotional vehicle, Leyland ensured the truck's fit and finish was top notch. The burgundy and white paint job reportedly took 350 hours, the full white leather interior took nine 16-hour days, and a cabinet maker built a wood replica of the dashboard and centre console in French walnut. Coachbuilder Tickford designed a neatly-folding top that took two men to erect—and, according to the Motor road test—flapped so much in the wind that it was impossible to hear the person next to you. (The top was later replaced thanks to an improved design by Crayford.)

At 6560 kg (14,462 lbs), with air-assisted drum brakes, massive engine, tricky gear change, and an incredibly bouncy ride, it's obviously not a convertible that would have been right for just anyone. In red and white, however, I wonder if this long-forgotten truck could be found and resurrected by an eager shopping mall Santa Claus.

He'd have to be careful, though, because there's one more clue this isn't any ordinary "heavy motor car": by law, no seatbelts were required.

"Ho, ho…oh."