Liebherr Unveils New LR 11350 Crawler
At its 2006 Customer Days in Ehingen, Germany, Liebherr announced the addition of the LR 11350 to its crawler crane product line. A pre-series production model with a 1,377-ton maximum load capacity is already being used in China for the construction of a chemical plant. The maximum load capacity of this heavy-duty crane has been increased to 1,488 tons.
The new machine has an overall boom length of 748 feet. With the addition of a main jib and luffing fly jib each 374 feet in length, the maximum height under hook is 731 feet. When mechanical outriggers are used, the LR 11350's conventional A-frame design allows the main boom lengths to reach 334 feet without the need for derricking. With derricking, main boom lengths are up to 492 feet.
A Liebherr ballast trailer with stepless hydraulic radius adjustment (49 feet to 98 feet) is available for the 137-foot derrick boom. A derrick ballast weighing up to 727 tons with a radius of 98 feet is used in this instance. The alternative is a suspended ballast system, which operates with stepless adjustment without a guiding device via the derrick boom up to a ballast radius of 82 feet, has already proved successful on the company's LR 1350/1. A guiding device is available to increase the radius to 98 feet. Ballast weights up to 375 tons can be accommodated on the LR 11350 slewing platform.
An overriding criterion in the design of the new LR 11350 was the need to transport the components economically and easily. As a result, no section exceeds a transport width of 11 feet or transport weight of 49.6 tons. To arrive at this weight for crawler carriers, the crawler tracks were removed, which is a less time-consuming procedure than taking the crawler carriers apart. Although the crawler carriers weigh approximately 77 tons, they can be transported as a complete unit provided that such laden weights are legally permitted.
A hydraulic ram on the A-frame enables the track to self-assemble. The design of the jib also reflects the needs of economic transport logistics. For example, the luffing jib intermediate sections can be inserted into the intermediate sections of the main boom with the aid of rollers. The LR 11350's diesel engine, hydraulics, electrical components, and operator's cab can be transported as a complete unit.
The slewing platform and the crawler mid-section are not separated at the slewing ring. Instead the under-section of the slewing platform, the slewing ring and the crawler mid-section comprise a single 49.6-ton transport unit.
The 870-hp six-cylinder Cummins diesel engine drives the new 1,488-ton crawler crane. Up to six winches can be used for installation purposes and hoisting work. The hoist winches have a rope diameter of 1.5 inches and operate at 310 kN cable tension. The hook block for load capacities of up to 1,488 tons has a modular design and consists of a hook and four roller blocks. This means it can be used for a variety of applications in the double- or single-block formats.
Adhering to safety standards was also an important criteria in the LR 11350's design. For example, the undercarriage has a 360-degree platform with railings and is accessible from two sides up ladders. The platform provides safe and comfortable access to the slewing platform and the operator's cab.