Smart Turns a Car into a Train – Smart Forrail is Designed for One-Track Minds

By Steve & Tamami Laser

Those clever chaps at smart are at it again. They’ve turned the new smart forfour car into a mini-train. The idea is to make a smarter way to get from point A to point B. In other words, it’s a tiny commuter train.


A special note from smart: Do not try this at home…

Smart says that the new smart forfour is a pretty effective point-to-point machine. “It can drive from London to Aberdeen non-stop for as little as £39. Its four occupants will be comfy on the 540-mile journey too, even if they’re significantly taller than the car is wide. The smart forfour is tiny on the outside, yet clever engineering means its interior is vast and is packed with technology to help make the journey fun, relaxing and safe. It stands a good chance of being the ultimate commuting machine, were it not for one obvious rival.”

“The forfour is reliant on roads, meaning the humble train has an obvious advantage in that it can get from point-to-point through a more direct route. When it comes to outright speed and ruthless efficiency, it’s one-nil to the train. Not all is lost, though. A light-hearted, one-off experiment by smart may have redressed the balance – the aim being to see if the two could be combined. Nicknamed the smart ‘forrail’, it might appear like a lightly modified smart forfour but it’s, in fact, a fully certified, mini-train,” says smart.

RP - Smart Rail-64

According to the automaker, the smart’s tridion safety cell gives it immense strength, which underpins the forrail. “No matter how simple Roger Moore made it look in his Mercedes-Benz 250 SE, removing the tires and placing it on tracks isn’t really possible in real life – the car would fall off almost immediately.”

Smart says that six months of engineering work and sophisticated CAD modelling later, the smart forrail is equipped with unique, solid steel wheels each measuring 22-inches in diameter and weighing 80 kg, allowing it the traction it needs on rails.


Designed by Interfleet, a specialized British train engineering business based in Derby, the team – who usually work on 16-liter, 70-ton diesel locomotives, had to employ a new approach to the challenge presented by a 999 cc, one-ton smart.

“The agile steering, which in road use allows the smart forfour to handle as if it’s on rails, was disconnected by engineers, to allow it to handle being driven on rails. To avoid any steering movement, aluminium supports were welded between the axles meaning the wheels are locked in position,” says smart.


Under close supervision, the smart forrail tentatively took to the tracks at the weekend on the privately operated Bluebell Railway – providing a few, bemused commuters the chance to avoid the congested roads without having to leave the comfort of the compact four-seater. The 10-mile stretch of railway, cutting a direct route through Sussex, represented a challenge for the smart forrail, and yet the smallest train on the tracks took the trip in its stride, and the regular enthusiasts (present for a model railway exhibition) somewhat by surprise.


Despite challenging engineering obstacles, the experiment steadfastly refused to come off the rails. The best of both worlds were combined – albeit briefly – to create arguably the most efficient, and fun, commuting machine in the world. Shortly after, the forrail reverted back to its forfour, road-going alter ego – content with being spectacularly efficient, fun and ideal for commuting. On tarmac.

More notes from smart: The forrail project met and exceeded the safety standards expected of it by the operators of the Bluebell Railway. It was supervised by trained staff from the railway at all time, with a licensed train driver in the car throughout. Each of its runs took place at low speed. The conversion from a car to a train took six months, and involved smart and Interfleet specialist engineers to design and create the wheels for the car. After the experiment was completed, the car was returned to its road-going form. Smart and Mercedes-Benz do not encourage any individual to carry out similar modifications. It’s incredibly difficult. In line with expectations, the smart forrail did indeed handle as if on rails.

News source: smart UK media. Photos © Mercedes-Benz

Story ©2015