In Edinburgh (Scotland), three Liebherr 630 EC-H 40 Litronic top-slewing cranes were involved in the Forth Crossing Bridge construction that was opened last year. This 2.7 km long bridge is the world’s longest cable suspension bridge with three pylons. In addition to the crane delivery, Liebherr was responsible for their overall development. This included a special design for the high wind speeds which prevail in this region, as well as the required calculations for the guying on the pylons and the loads for the caisson foundation.
630 EC-H 40 Litronic climb on bridge pylons
Each of the three tower cranes stood on a client-constructed steel foundation known as a caisson, on the bridge pylons in the water. The tower
cranes were installed using a barge, on which a crawler crane stood.
Previously, the individual crane parts were assembled on the mainland. 630 EC-H 40 Litronic tower cranes are ideal for such applications. The cranes are equipped with 36-metre jib and lift up to 18 tonnes at the jib head. At a radius of up to 18-metre, the cranes are designed for a 40-tonne capacity.
High loads – high handling capacity
This configuration enabled a particularly high handling capacity with heavy loads. This lifting capacity was also supported by the 110 kW high performance hoist gears from Liebherr which were in use on the project, and which guarantee fast lifting speeds.
Height under hook up to 212 metres
To adapt to the high wind speeds resulting from the open North Sea location, the cranes were specified according to wind zone “D 25” and configured with the particularly stable 24 HC tower system. The cranes were stationary mounted on 10-metre 630 EC-H undercarriage. In total, just five guying systems on the pylons were needed to reach the hook height of 212 metres.
The special guying systems were manufactured by the client, on the basis of designs and structural calculations provided by Liebherr. The company is keen on supporting its customers for their projects in India through its Mumbai-based subsidiary Liebherr India Pvt Ltd (Tower crane solutions).
For more details, visit www.liebherr.com