Liebherr NC-B 12-70 flattop tower crane performs first job in Madinah museum build
Staff Report, January 25, 2022
Designed for price-sensitive markets, new model with 12t lift capacity and 70m jib length takes up challenge of narrow space in Safiyyah Museum and Park project
Liebherr’s NC-B 12-70 flattop tower crane, the newest and most powerful in the manufacturer’s NC-B series, is currently on its first job on a museum project in Madinah, Saudi Arabia, where it is meeting the challenge of limited space and a need for precise operation.
The 12-tonne model has a long reach and is suitable for both cast-in-place concrete construction as well as for the precise lifting of heavy prefabricated parts, said Liebherr. Part of the NC-B series, which is designed for price-sensitive markets and customers, it is available for order now, added the manufacturer.
At the job-site of the ‘Safiyyah Museum and Park’ project in Madinah being built by the contractor MOBCO for Construction and Civil Works, a simple look from above is enough to see the biggest challenge presented by the site: the lack of space. High-traffic roads and tall neighbouring buildings required crane operations to be planned with precision, something which Liebherr Tower Crane Solutions closely supported, says a statement from Liebherr.
With its maximum jib length of 70 metres and a lifting capacity of up to 12t, the NC-B 12-70 is “reliable, economic and safe in its work”, added Liebherr. In addition, the tower crane also offers a jib head load capacity of 2t at maximum jib. These technical features make the crane an optimal solution for high-performance lifts in densely built-up metropolitan areas, said the manufacturer.
It was Liebherr’s professional approach and fast execution of measures that impressed MOBCO. The contractor is building the Safiyyah Museum and Park in the centre of Madinah, with the project comprising a museum, shops, cafés and a public garden complete with palm trees.
According to Liebherr, the NC-B concept is optimised for transport and assembly. “Five trucks deliver all elements of the slewing part with 70m jib length to site quickly and easily. Standard-sized containers can be used for transport. Once on site, assembly is straightforward. The central unit with slewing platform and connection element only requires one lift. A weight reduction of the central unit is also possible: If needed, the slewing platform, control cabinet and cabin can be installed separately to meet the assembly crane’s performance capacity,” said Liebherr in its statement.
It added that established technologies from Liebherr’s existing Flat-Top series further accelerate assembly. The LiConnect quick connection system enables the jib to be assembled quickly and safely in 5m sections.
“Both of Liebherr’s 16 EC 240 and 21 HC 290 tower systems are compatible with the NC-B 12-70 crane, whereby the 16 EC tower system, measuring 1.6 x 1.6 metres, has been specifically designed for use with the NC-B series. Pin connections ensure the 16 EC 240 system’s straightforward, economical assembly. The tower sections have a standard length of 3.9m, which enables climbing on the building. Longer tower sections of 11.7m can also be used for efficiently achieving a freestanding hook height of up to 50m. Using the 21 HC 290 tower system, the freestanding hook height can be increased up to 77.7m,” said the manufacturer.
The hydraulic climbing unit is suitable for both internal and external climbing and is detachable and compatible with other Liebherr tower cranes. As a result, the operator only needs one device, which can be used on various construction sites, added Liebherr.
The hoist gear, slewing gear and trolley are controlled by a frequency converter. This makes stepless acceleration during lifting, lowering and slewing effortless and enables high-precision crane operation. Drive units with frequency converter provide good handling characteristics and also minimise the risk of damage to the crane, and flatten occurring power spikes.
Among other features, Liebherr added that the Micromove smart assistance system, which ensures exact positioning of heavy loads, is included in the package as standard. Additional options include the ABB operating range limiting system and the EMS electronic monitoring system with sensors included. Assistance systems provide reliable support for crane operators during lifts and contribute to site safety. An optional slip ring unit also supports safe operation. This allows infinite slewing of the crane on site without the risk of cable breaks.
Liebherr also offers a 6t version as part of its NC-B series in the form of the NC-B 6-62. The series is specifically designed to meet the requirements of price-sensitive markets and customers, the manufacturer adds, and short delivery times are available for both series without compromise on in-house technologies – thanks to the production site in Pune, India, Liebherr is able to manufacture cranes in the region for the region.