Linden Comansa added the final model, the 21 LC 660 tower crane, to its LC2100 series. Designed under EN 14439 European standards, the crane is available in four versions, depending on the maximum load: 18, 24, 36 and 48 tonnes (39,680; 52,910; 79,360 and 105,820 pounds). Targeted for use in public works, industrial construction, mining and infrastructures, the new crane will be available starting in July 2012.
Based on the design of the company’s 21 LC 750 tower crane launched in 2009, the 21 LC 660 tower crane’s first jib and counterjib sections are assembled together directly over the slewing platform through fast conections, which saves time, reduces costs in auxiliary equipment and improves safety. Most of the jib sections of the 660 are the same as the 750, which enhances the modularity and section interchangeability between both cranes.
A new D35 mast section was designed for the tower of the 21 LC 660, which is more economic than the tower section of the 21 LC 750 (D36). Both sections have the same dimensions (5.5m high and 2.5m wide or 18 feet high and 8.2 feet wide), which makes them compatible and enables them to share the same hydraulic jacking cage. The D35 mast sections can be divided in four panels, are easy to assemble and transport, and are easily joined to other sections by pins.
The crane offers two standard tower configurations: The first uses only D35 tower sections, allowing the crane to achieve a freestanding height of 73.3 meters on fixing angles (240 feet), or 69.9 meters on stationary or travelling base (229 feet). The second configuration combines D35 with D36 sections, and allows the 21 LC 660 to reach a height of 78.8 meters on fixing angles (258 feet), and 80.9 on base version (265 feet). The modularity of the different tower sections also enables several alternative configurations, allowing the 21 LC 660 to reach a freestanding height of 124.8 meters (409 feet).
The 21 LC 660 also features Linden Comansa’s latest features, such as its Effi-Plus high speed hoist mechanisms, which enable hoist speeds up to 244 meters (800 feet) per minute; its PowerLift System, which improves 10 percent of the load diagram with reduced speeds; and its slewing mechanisms with frequency control for reduced energy consumption.
The standard 110 kW (148 hp) hoist engine has a Lebus drum with capacity for 1,450 meters of rope (4,747 feet). Two other engines, with rope capacity of 790 meters (2,592 feet) and with 110 and 65 kW (87 hp) respectively, are available as options.