Liebherr helps Breuer&Wasel deliver added bite for mining giant
German heavy load logistics company, Breuer&Wasel has utilised three Liebherr mobile cranes to undertake an upgrade to the bucket wheel of an overburden excavator at a large open-cast coal mine in Germany.
Mobile cranes owned by Breuer&Wasel are a common sight at the Hambach open-cast mine, with seven units operated by the Bergheim-based company, permanently stationed there.
The three additional Liebherr mobile cranes were sent to the site to provide reinforcement, to assist in fitting a new 140-tonne bucket wheel to the huge overburden excavator.
The replacement of the bucket wheel was the ultimate part of the general overhaul of the giant machine, which took three months after 33 years of service. Weighing in at a total of 13,000 tonnes, 96 m high, and some 200 m long, ‘Excavator 290’ is among the biggest machines of its kind in the world. Since 1978 the 18 buckets of the mighty excavator, with a traction force of 100 tonnes, have been digging through sand and gravel, and in the process have moved close on three billion cubic metres of earth.
The new bucket wheel, 18 m in diameter and weighing 140 tonnes, was initially delivered in individual parts and assembled at the installation site, still without its buckets. This was when the three Liebherr mobile cranes, an LTM 1500-8.1, an LTM 1400-7.1 and an LTM 1350-6.1, first got to work, turning the wheel which was still lying in the position in which it had been assembled, and loading it onto a heavy load crawler unit. Special fastening equipment had to be constructed especially for tilting the load.
All three cranes were then used to make the lift and pivot the wheel into a vertical position. The two bigger cranes then held the wheel, while the 350-tonner moved to the other side and was reconnected Once the load was again lying horizontal, the special crawler unit was positioned beneath it, ready to take on the 140 tonnes of steel.
The crawler had to cover 200 metres, with the bucket wheel on its shoulders, to reach the excavator. There the process of getting the wheel upright was repeated.
“We also had to follow the special safety instructions from the clients, which stipulated that, during the tandem lift, the cranes could not be subjected to more than 80 percent of their maximum capacity”, as Jürgen Oprée explains, technical director at Breuer&Wasel.
It took two days for the crane experts from Bergheim to turn, transport, and install the bucket wheel on the site. The specialists from RWE Power AG, which operates the mine, which covers 38 sq km and is up to 370 m deep, had taken two years to plan and prepare for the huge excavator to be overhauled, and the refurbishment cost RWE around EUR11 million (USD13.6 million).
It will still be some three decades before the brown coal reserves at the Hambach mine are fully exhausted – and the giant’s new set of teeth should easily last that long.