|Three Liebherr 1250 HC tower cranes lift 40- and 50-ton maximum loads during construction at the Sierra Gorda copper project in Chile. Two other 1250 HC 40-ton-capacity Litronic cranes are conducting similar work at Escondida.|
Five Liebherr 1250 HC tower cranes are being used at two major mining projects under construction in Chile's Atacama Desert region. The large 40- and 50-metric-ton (mt) cranes currently in use at Escondida and Sierra Gorda offer lifting capacity equal or better than almost any other tower cranes working in Latin America, according to Liebherr.
Two of the company's 1250 HC 40 Litronic tower cranes, mounted on foundation anchors, are being used at the Minera Escondida copper mine. Both machines have a working radius of 52 m and hook heights of 40 m and 52 m, respectively. During the construction phase, they are expected to handle loads of up to 20 mt.
After current construction is completed, the two Liebherr tower cranes will be used for maintenance purposes.
Meanwhile, three 1250 HC tower cranes are in use at the Minera Sierra Gorda copper project. Two of these cranes are rated at 50-mt capacity and the third at 40 mt.
The 1250 HC 40 has a hook height of 34.9 m and a working radius of 51.9 m. The two 1250 HC 50s are configured with hook heights of 68.6 and 69.6 m and each has a working radius of 38.8 m.
During the current construction phase, the cranes are being used to assist in component handling for process tank assembly, lifting loads of 14 to 17 mt per component.
In the future, all three cranes will be used as maintenance cranes at the mine. One 1250 HC will support maintenance work on the mill's flotation cells. The two others will support service and maintenance work on ball mills.
Liebherr said the extreme geographical and climatic conditions of the two project sites not only present challenges to the workforce but also to the crane equipment. The extreme day/night temperature differential-up to 40°C variation-and dust present in the arid desert climate generate higher-than-usual stress on machinery.
In addition, Chile is one of the most earthquake-prone countries in the world, and earthquakes up to a magnitude of 5 are not uncommon.
This requires that the cranes must comply with Chilean standards to ensure they are earthquake-resistant.