Liebherr has just unveiled its third and largest NC-B flat-top tower crane at the Excon exhibition – the NC-B 12-70. The show is currently taking place in Bangalore, India, from 10 to 14 December 2019.
The new NC-B 12-70 has a maximum lifting capacity of 12 t, maximum radius of 70 m and jib head load capacity of 2,000 kg – it is significantly larger than the NC-B 9-62 and NC-B 6-62 models. A specific 16 EC tower system has been developed for the NC-B cranes, and the series also has its own variable climbing system.
The NC-B series is specially designed for use in metropolitan areas of emerging countries. The first three models can cover a wide range of construction projects in these areas. The 9-t and 12-t versions are ideal for lifting heavy prefabricated components – for building shopping centres, production plants, car parks, etc. Meanwhile, the 6-t NC-B 6-62 model is perfect for erecting tower blocks in inner-city areas where they work with low load weights but enormous hook heights.
For the new NC-B 12-70, customers can choose from a frequency converter standard hoist gear with a rating of 45 kW or an optional 75 kW hoist gear, also with a frequency converter. The 75 kW hoist gear can achieve hook heights of up to 492 m with high handling capacity in two-line operation.
Liebherr manufactures cranes tailored to suit the local market in India at its Liebherr CMCtec India Private Limited site, which was opened in 2012 in Pune, ensuring short lead times whilst still adopting the German technology.
The new 16 EC tower system with external dimensions of 1.60 m x 1.60 m was developed for the new NC-B cranes. As usual with tower systems in these classes, the tower sections are connected using pins and are climbable. The standard length of the tower sections is 3.90 m. Extended tower elements with a length of 11.70 m can also be used to reach a maximum freestanding hook height of 53.20 m quickly and at low cost.
The hydraulic climbing unit is suitable for both internal and external climbing. It can be removed in full and is compatible with other Liebherr tower cranes. This means that operators only require one unit, which can then be used at different sites.
In contrast to existing Liebherr flat-top cranes, the new NC-B models have a full jib element rather than the compact head. This is also designed for transporting in containers but costs less than a compact head. Depending on the size class of the auxiliary crane, the slewing platform, switchgear cabinet and cabin can also be assembled separately. The new concept includes a large number of elements from existing Liebherr top-slewing cranes, such as the LiConnect jib connection system. This enables the jib to be shortened or extended quickly and easily in steps of five metres.
Crane control system
Both the hoist and slewing gear and the trolley are controlled by a frequency converter. This makes infinite acceleration for hoisting, lowering and slewing possible, ensuring highly precise crane operation.
The Micromove fine positioning mode is included in the package as standard. The ABB operating-range limiting system and EMS electronic monitoring system are also available as options.
There are also other ways of upgrading apart from the control system. The options include slip ring assemblies for endless slewing, a remote control for easy control from the ground or an anemometer for safe crane operation.