The versions of 24, 36 and 48-ton of both models have increased their maximum load capacity to 25, 37.5 and 50 tons. This improvement is achieved by use of a compacted wire rope, of smaller diameter, and an optimized design of the now lighter trolley-hook set. Such changes not only increase the maximum load capacity of cranes, but also improve the loads in all radius, 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 a model, which allows up to six different configurations according to the jib length. The advantages of this new counter-jib and its good acceptance 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 50m jib (164ft), the counter-jib radius is 25m instead of 31 of the previous design (82ft instead of 102ft).
COMANSA's models 21LC660 and 21LC750 improve their performance significantly
As a novelty in terms of jib length, COMANSA now offers an optional 90m radius (295.3ft) 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 20ton version of 21LC660) now feature a new optional hoist mechanism (132kW - 177hp), which allows speeds of up to 300m per minute (984 ft/min). COMANSA also added the Effi-Plus system to the optional 110 kW hoist mechanisms (148hp), available for all versions of such models. This system, which was already implemented in the other motors of both models, increases the hoist speed by almost 15% 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 720m or 1,570m (2,360 and 5,150 ft), which allows these cranes to work with heights under hook of up to 785m (2,575 ft).
To simplify and unify the range of tower sections, the 21LC750 now has the D36B as a 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, which was the standard for the 21LC750, and will now be discontinued.
The "new" 21LC660 and 21LC750 cranes are now available worldwide and are shipped with the XL-size CUBE cab as standard. With its fully glazed front part and its spacious design, the new cab represents an important improvement in the productivity and comfort of the crane operator.
The 21LC660 and the 21LC750 cranes are two of COMANSA's models with best acceptance globally because of their productivity and competitiveness. These cranes have worked in projects in Germany, South Korea, Canada, Angola, Singapore, Sweden, Qatar, Australia, Argentina, Hong Kong, Ivory Coast, etc.
Few manufacturers offer tower cranes with 50-ton maximum load in their range, and most of those cranes have pendant lines, with the disadvantages that this represents. In addition to the Flat-Top design, models 21LC660, 21LC750 and 21LC1050 offer advantages such as ease and safety of erection and enormous versatility and modularity.
Summary of improvements of 21LC660 and 21LC750 models
- Increase of the loads, including maximum load capacity: 25, 37.5 and 50 ton/ 55,120, 82,670 and 110,230 lb (not applied in model 21LC660 20 t - 44,090 lb)
- New modular counter-jib design for reduced radius
- Optional 90-m jib length for special projects (295.3 ft)
- New 132kW / 177hp hoist mechanism (not applied in model 21LC660 20-ton 44,090 lb)
- Increase of hoist speeds in the 110 kW mechanisms (148 hp) due to the Effi-Plus System
- Larger wire rope capacity.