ALE demonstrates record heavy lifter

What is claimed to be the world's highest-capacity land-based crane has been unveiled in the iron. ALE has shown its 4,300 tonne capacity AL.SK90, pictured undergoing load testing in early September, to customers and potential users. It is rated at 96,000 tonne-metres.

The double lattice boom crane has some interesting and unusual features. Instead of the ballast swinging at radius behind a central slewing point, usually near the foot of the boom, the SK90 slews around its ballast. For lighter lifting jobs a 600 tonne capacity winch system can be used instead of the group of 900 tonne capacity heavy lift strand jacks. Boom luffing is achieved using a large hydraulically driven chain type pendant system.

Primary applications for the AL.SK90 are construction of modular buildings and the onshore construction of offshore oil platforms and other large modules.

All parts of the AL.SK90 are within the size of standard 20 or 40 foot shipping containers and weigh 36 tonnes or less, ALE said. As pictured, there is 4,000 tonnes of ballast in the grey containers at the rear of the crane while the test load is around 1,500 tonnes suspended using four 900 tonne capacity strand jacks from 130 m of boom at a radius from the pin (at the foot of the boom, not the centre of the ballast) of around 40 m.

Parts of the AL.SK90 can be combined with others to build the 5,000 tonne capacity AL.SK120 strand lifting system. Preparations are underway to create this 134,000 tonne-metre giant.

For more details on this crane see the October issue of International Cranes and Specialized Transport magazine.