The new 1250-tonne crawler crane offers system lengths of up to 228m with a main mast of 114m and a luffing fly jib also 114m in length. Thanks to its design principle with a conventional A-frame, the LR 11250 can, in conjunction with mechanical supports, erect main boom systems of up 102m in length without a derrick system. Main boom lengths of as long as 150 m can be erected using a derrick.
A Liebherr ballast trailer with hydraulically continuous radius adjustment is available for the derricking boom. A derrick ballast of up to 600t is used in this instance. A suspended ballast system is available as an alternative.
During the design phase for the new LR 11250, cost-effective and easy transportation of the components was of primary importance. For instance, no parts of the crane exceed the transport width of 3.5m and the maximum transport weight of 45t. Boom design meets the needs of economical transport logistics. For example, for transportation purposes, the intermediate sections of the fly jib can be inserted into the intermediate sections of the main boom with the aid of track rollers. The LR 11250’s drive unit with diesel engine, hydraulics, electrics and crane cab can be transported as a complete unit.
A six-cylinder Cummins diesel engine developing 640kW provides sufficient drive power for the new 1,250t crawler crane. Up to six winches are used to erect the LR 11250 and for hoisting tasks. The hoist gears have a rope tension of 310kN and a rope diameter of 38 mm. The hook block, with a lifting capacity of up to 1,250t, is modular in design and comprises a hook and four roller blocks. This allows it to be modified without difficultly for different applications.
An important criteria when it came to designing the new crawler crane were high safety standards. For instance, on the chassis there is a 360 degree platform with rails, which can be accessed via steps from two sides. The platform offers safe and convenient access to the superstructure and crane cab.
The first crane of this type is currently being set up for testing at the Liebherr plant in Ehingen. At the beginning of 2006, it will be shipped to China where it will be used to construct chemical plants.
