Star Wars backdrop as
an extreme test setting.

The Unimog bravely defies the adverse conditions of open pit mining.

A journey into the Hambach open-cast mine is truly impressive. A lunar landscape of gigantic proportions - dominat­ed by eight bucket wheel excavators that are among the largest of their kind in the world. Sascha Funk has been working for RWE Power AG for 10 years and, together with his colleague Jörg Rübsteck, is respon­sible for procuring material and vehicles for the gigantic fleet.

“Our total fleet com­prises around 800 vehicles, from electric cars for business trips and courier deliver­ies between the locations, to 40-tonne trucks for transporting materials in the pit,” says Sascha Funk, describing the extent of his work duties. Jörg Rübsteck is primarily occupied with procuring Unimog vehicles for the RWE fleet: “I have been handling Unimog, specially tailored to our needs, for 15 years. They have been an integral part of our vehicle fleet for over 40 years, and we have enjoyed highly constructive cooperation for all that time,” he reports. RWE's reliable partner is the Unimog general agency RKF-Bleses GmbH, from advice to service.

126 Unimog ensure trouble-free operations.

The Hambach open-cast mine has long been regarded as the ideal test site - including for the 126 Unimog vehicles in the fleet. “Most of our Unimog vehicles are equipped with a flat bed, a crane and a winch. They are the tools we need most,” Jörg Rübsteck explains. A U 5023 with a built-on crane has just been put into service; shortly before that, a U 4023 with a flat bed and a large double cab.

The special challenge is the difficult ground - a highly unusual mix­ture of sand, lime, clay, rock and water, which continually penetrates into all the vehicle components and causes heavy wear. “We’ve even had vehicles with their brakes completely worn down after just one hard day,” Sascha Funk says, highlighting the extreme conditions on-site. That is why all the Unimog units at the Hambach open-cast mine have an encapsulated final reduction gear. As well as dealing with the unusual ground mix, the vehicles are essentially run contin­uously in heavy mud. That is because the pit is permanently watered in order to prevent huge plumes of dust.

Off-road mobility and reliability are vital.

The main applications of the Unimog at the open-cast mine are for inspection and repair of the huge conveyor systems. “We constantly have to replace defective parts that can only be moved with a mobile crane,” explains Sascha Funk. The double-cab flat-bed Unimog is also a crucial means of transport on-site. A mobile team of technicians with heavy equipment is at work around the clock to safeguard the mine's output, keeping the 110 kilometres of conveyor belts that transport the coal from the mine running 24/7, 365 days a year. Jörg Rübsteck comments: “To ensure 24-hour operations, we check the vehicles in the workshop almost every time they're put into service.”

Talking of output: Year after year, the eight super-sized bucket wheel excavators carry 40 million tons of lignite - an essential factor in terms of Germany's energy supply. Five of the eight bucket wheel excavators are the largest in operation worldwide, each carrying 240,000 cubic metres of coal per day. With buckets that could easily fit a mid-size car in them.

Even the most fearless Unimog driver treats the mining behemoths with respect when he has to approach the monstrous chains. If a Unimog were to actually get under the chain of an excavator, the excavator operator would not even notice the slight­est vibration. But such a thing has never happened to Jörg Rübsteck and Sascha Funk's team in their many years working at the Hambach open-cast mine - and they will make sure that it stays that way.

Text: Christian Bonk, photos: Henrik Morlock

visible-md and up (hidden-sm and down)
visible-lg and up (hidden-md and down)
visible-xl