The Unimog – an expert on rail tracks.

Once freight trains were marshalled there and sent to steelworks or coal merchants, today 30 kilometres of track and an abandoned signal box make the operating site of the Société de Garage de Morsbach (SGM) resemble an industrial wasteland. But among the hundred brown freight wagons there is one that holds its ground: the two-way Unimog U 423. With its yellow metal bars and two large yellow compressed-air tanks on the load bed, the special truck immediately catches the eye. For shunting the many freight wagons, SGM employee Tatiana Gorgol could not imagine a better vehicle for the job. Because the Unimog U 423 can also be a locomotive.

The road-rail vehicle from Mercedes‑Benz is ideal for the daily assembly of freight wagons into complete trains. With ease, the Unimog U 423 pushes six four-axle hopper and flat wagons ahead of it while running in reverse. The 170 kW Euro VI engine of the Special Truck does what it promises. Tatiana Gorgol and her colleague Christophe Blanchard know this too.

When an owner needs their wagon, the perfectly coordinated team shunts it with the corresponding wagon number from its parking position onto the staging track. Throughout the entire shunting operation, Christophe Blanchard ensures the train is routed onto the correct track. If necessary, he has to change the points manually. For this he is also constantly in radio contact with his colleague at the controls.

To keep the Unimog on the rails, it requires separate, hydraulically controlled guide rollers at the front and rear. These four steel wheels adapt the tyre contact pressure on the rails to the prevailing conditions. Unlike a locomotive, the Unimog does not have a sand spreader to increase traction on wet or icy rails. An air pressure of 5 bar is required to release the pneumatic brakes of the wagons. Tatiana Gorgol and Christophe Blanchard obtain this from the Unimog's two compressed-air reservoirs.

SGM offers the only parking facility for freight wagons in all of France; wagons can be parked indefinitely. If an owner needs their wagon, an email with the wagon number is sufficient. Ordered wagons are shunted from their parking spots onto the staging track; twice weekly a locomotive collects the wagons there. Each of SGM’s largest customers — STVA, ERMEWA and VTG — stores up to 80,000 wagons on the SGM site, which means plenty of work for the Unimog.

Tatiana Gorgol is more than convinced of the 2-way Unimog. She says it is the ideal vehicle for this job. Unlike a locomotive, it does not have to be warmed up for an hour before it can be used. "Besides, it can simply drive off the rails when it is needed for shunting at the other end of the train" — another plus of the Special Truck that the Unimog driver appreciates. No wonder, then, that in Morsbach, France she can no longer — and does not want to — do without the Unimog U 423.