THE DUTY CYCLE CRAWLER CRANE THAT CHANGED LIEBHERR

The homecoming of the HS 870

Manfred Brandl never thought that he would see this machine again one day. Yet the two are connected by a story that changed Liebherr. Why? Well, Liebherr-Werk Nenzing (Austria), where Manfred Brandl started as a production worker and left as managing director four decades later, very nearly developed completely differently and would almost certainly still be building ship cranes today: if it hadn’t been for this duty cycle crawler crane, which carried out lifting work in a gravel pit close to Bonn (Germany) day in, day out – rusty but steadfast, 40 years after it was built. It was discovered in 2014. The then sales manager for duty cycle and crawler cranes for Germany examined it himself and reported something unbelievable to his colleagues in Nenzing: he had the forefather of construction machine production in Nenzing in front of him – the prototype of the duty cycle crawler crane HS 870 with the serial number 181001. For Manfred Brandl, this reunion would become unforgettable.

The forefather needs more than just a lick of paint

Jürgen Grass, Head of Assembly, has had to face more than one challenge in 35 years of working in construction machine development. Yet hardly any was as special as this one. He will probably always remember the homecoming of the HS 870 duty cycle crawler crane. That was in February 2018: “I can still see it before my eyes. Its condition was good, considering the circumstances. The motor and hydraulics were still working flawlessly. Nevertheless, time had left its mark on our first duty cycle crawler crane. In its 40 years of service, the machine wasn’t exactly handled delicately.” One thing was clear. If this part of Liebherr history was to be saved, more than just a fresh coat of paint would be needed.

But how do you restore a machine that established a whole era? “Since we are specialised in building new machines at Nenzing, we repeatedly had to decide just how much we wanted to restore. We wanted to preserve its character, of course. It was really hard for us not to make this vintage duty cycle crawler crane look as perfect as a new machine.”

A team of mechanics, fitters, engineers and apprentices got down to business. Young and old, new and experienced employees helped and lent a hand. The undercarriage was in desolate condition and required a lot of time and attention; the travel drive had to be restored completely. The steel covering had suffered during the many years of service and was built from scratch by the apprentices. Valves were renewed, hydraulic hoses replaced and old pumps and motors were dismantled into their component parts, cleaned and reassembled. Besides original replacement parts, even high-tech from the 21st century found its way into the HS 870; despite a long search, replacement parts couldn’t be found for the headlight covers, “we then replicated them with a 3D printer, true to original,” Jürgen Grass says.

Jürgen Grass is proud of his employees. To him, the restored HS 870 is an example of what inventive talent and teamwork can accomplish. “We have many excellent and experienced employees here with us. Some of them were even involved in the construction of the HS 870, 40 years ago.” They put more than 700 hours of work into the restoration, on top of their daily work in production. A master performance during which all those involved were able to experience history up close. “This is why it was so important to us to include our apprentices in the restoration. For them, everything was particularly exciting. They could experience how our HS series first started. Today our duty cycle crawler cranes are completely digital, in 1980 everything was still analogue.”

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