Always right in the middle

This is the specialty of Wasserbau Wusterhausen. The helper that stands by the company's side is even more uncompromising than its employees when it comes to off-road operations: the Zetros.

As the blue Zetros with the number plate OPR-MV 900 leaves the road and turns onto the construction site, Enrico Klein switches to off-road transmission. Thick fog hangs over the area this morning, drifting in from the nearby River Elbe, which is hardly a kilometre away. The track is lined with crushed rocks and potholes, the ground gradually becomes deeper and more clay-like, and water stands in the knee-high ruts — child’s play for the 240 kW off-roader with its waist-high tyres.

“This is nothing,” says Klein in a strong Berlin dialect, almost a little disappointed, as he parks the off-roader. He talks about a two-kilometre approach to a construction site over a rutted dirt track that was completely under water. Wasserbau Wusterhausen GmbH had just bought the three-axle vehicle, and Klein wanted to try out what it could do. “Even the tracked vehicles could hardly get through. This vehicle cut through the terrain like a hot knife through butter — even with a full load. It was flawless. Hats off!”

No surprise really: the Mercedes‑Benz Zetros is built for off‑road terrain. The all-wheel-drive vehicle fords water ditches 80 centimetres deep and climbs slopes of up to 80 per cent in crawler gear. Because the axles are extremely articulated, even extreme potholes are no problem for the heavy vehicle with a gross vehicle weight of 27 tonnes. The 6-cylinder engine permanently powers all axles via a 9-speed transmission.

Klein and his colleague Matthias Beckemeier have driven the powerhouse 160 kilometres to get to the construction site, and the journey from Wusterhausen, not far from Berlin, to Darchau took just under two and a half hours. In the small town in the Lüneburg district of Lower Saxony, a new biogas plant is to be built. The first of the six mighty circular concrete containers that are planned stands on the site, up to 42 metres in diameter and eight metres high. They will be filled with maize, which will ferment inside. The plant is expected to generate 2.6 megawatts and will supply the region with electricity and heat.

“Our job is to lower the groundwater so that the civil engineering crews can work calmly and safely,” says Beckemeier. For this purpose wells are drilled, pumps connected and pipelines laid. With its 36 employees, Wasserbau Wusterhausen GmbH operates nationwide. Beckemeier was recently out with the Zetros in Dortmund and Gütersloh. “Long distances are absolutely no problem. The ride comfort is high — we arrived completely relaxed.”

Whirring, Enrico Klein extends the side supports using the remote control. The Zetros shudders as they meet the support plates and press them into the ground. A display behind the cab lights up, showing 100 percent. “We operate almost exclusively in rough terrain. Often the mud is knee-deep. The vehicle must stand securely, otherwise we can’t work,” says Klein. Occupational safety is the top priority: the crane, which can still lift 1.4 tonnes at ten metres, is also controlled by remote — so the operators are always kept outside the danger zone.

The body of the Zetros 2733 comes from Hüffermann Transportsysteme. It is precisely tailored to the needs of Wasserbau Wusterhausen. Six vacuum piston pumps, each weighing 1.6 tonnes, fit on the load bed. With the additional drill string there is still spare capacity with a ten-tonne payload. "We normally use the Unimog for drilling and the Actros for the materials. Now we save two or three trips. The material for an excavation goes entirely on the Zetros, with pumps, filters and everything," enthuses Klein.

The decision to buy the versatile heavyweight was made by Meinhard van Rüschen, managing director of Wasserbau Wusterhausen GmbH. He was already convinced of the Zetros when he saw it in photos. His salesman Torsten Liebig from Autohaus Jürgens in Neuruppin had shown them to him. "I immediately thought: This one screams for work — it's a beast for tough terrain," recalls the native of Cloppenburg. "I still feel the same today."

Van Rüschen made a point of going with them in the spring to pick up the vehicle from the factory in Wörth. "Seeing it for the first time in our blue company colour was a special moment. Not only does it do its job superbly, it also motivates my employees. They think it's great – and so do the customers, by the way." He is now negotiating the purchase of a two-axle Zetros.

With both feet firmly in the mud, Enrico Klein stands a few metres from the vehicle and uses a remote control to operate the crane. A pump hovers through the air; he sets it down some distance from the Zetros. The crane can rotate 360 degrees. Because the Zetros is low, you can work in front of and behind the vehicle. And — important for the waterworks crew — you can drill on both sides. "The working range is twice as big as before," praises Klein. "We no longer have to reposition the Zetros so often, we get a lot more done and are also more flexible."

Transporting pumps and wastewater pipelines is a core part of the Wusterhausen firm's business. Four of these pumps rattle across the site, day and night, seven days a week. Each can pump up to 90,000 litres of water per hour. Pipes carry it into a trench, from where it flows into the Elbe.

Hardly has the pump been set down when Klein and Beckemeier attach a rotary drilling head to the crane. The drill string is fixed to it. Klein had previously marked the drilling point with a spray can; the drill is positioned exactly there. "Goes in well," says Beckemeier contentedly as the auger slowly turns into the ground. The drill diameter is just 120 millimetres; drilling can reach up to seven metres deep. At first the ground is dark and clayey, then it becomes greyer, sandier and wetter. Dozens of small wells are scattered across the site. Klein kneels over the borehole and lowers a light plummet. At 2.30 metres it hits groundwater and begins to glow. The nearby Elbe makes itself felt; the ground is damp.

Klein and Beckemeier dismantle the drill string, clean it and stow it on the loading area. They reel in the crane and retract the outriggers. The Zetros is ready to drive again. Enrico Klein climbs into the cab, which on this bonneted model is set back behind the front axle. That not only gives it its characteristic silhouette, it also makes it controllable on rough terrain. If the cab sat on the axle like on a forward-control vehicle, the driver would be tossed about as if he were a rodeo rider. Klein settles into the air‑sprung driver's seat, starts the 7.2‑litre diesel and moves the Zetros 50 metres. Before returning to Wusterhausen, there are still plenty of holes to drill.