COMANSA has introduced upgraded models 21LC660 and 21LC750. The design of new solutions for the 21LC1050 flat-top tower crane, launched recently, allowed COMANSA's R&D team to apply some of these developments to two of the manufacturer's most successful cranes. Thus, models 21LC660 and 21LC750, mainly designed for large industrial projects, energy, mining and PPVC construction, improve their performance significantly.
The versions of 24, 36 and 48 tonne (52,910, 79,360 and 105,820 lb) of both models have increased their maximum load capacity to 25, 37.5 and 50 tonne (55,120, 82,670 and 110,230 lb). This improvement is achieved thanks to the use of a compacted wire rope of smaller diameter, and an optimised design of the now lighter trolley-hook set. Such change not only increases the maximum load capacity of the crane, but also improves the loads in all radii including the jib-end load.
During the design of the 21LC1050, space restrictions at construction sites that exist in some countries due to regulation were taken into account. That is why a highly modular counter-jib was created for such model, which allows up to six different configurations according to the jib length. The advantages of this new counter-jib and its good reception in the market encouraged COMANSA to apply this design to cranes 21LC660 and 21LC750, which will improve the counter-jib radius of both models when they are erected with reduced jib-lengths. Thus, when the 21LC750 crane is erected with a 50-m jib (164 ft), the counter-jib radius is 25 m instead of 31, of the previous design (82 ft instead of 102).
As a novelty in terms of jib length, COMANSA now offers an optional 90 m radius (295.3 ft), for special applications. This option is available for the 21LC660 and 21LC750 models, as well as for the 21LC1050 crane.
Models 21LC660 and 21LC750 (except the 20t version of 21 NSA also added the Effi-Plus system to the optional 110 kW hoist mechanisms (148 hp), available for all versions of such models. This system, which was already implemented in the other motors of both models, increases the hoist speed almost 15 per cent with light loads. These two mechanisms greatly improve the productivity of the crane, especially when working at large heights. Both motors can have wire rope capacity of 720 or 1,570 m (2,360 and 5,150 ft), which allows these cranes to work with heights under hook of up to 785 m (2,575 ft).
To simplify and unify the range of tower sections, the 21LC750 now has the D36B as standard section. This mast is the same as that of the 21LC1050 flat-top and the LCL700 luffing-jib crane, and is fully compatible with the D36 mast section, with was the standard for the 21LC750 and will now be discontinued.
The ænew' 21LC660 and 21LC750 cranes are now available worldwide and are shipped with the XL-size CUBE cab as standard. Thanks to its fully glazed front part and its spacious design, this new cab represents an important improvement in the productivity and comfort of the crane operator.