With the increasing demand faces to handle larger components, UK-based company Abnormal Load Engineering Ltd (ALE) kicked off in development and unveiled their first machine built in 2008 – ALE AL.SK90. The 4,300 tonnes crane was designed specifically for a petrochemical contract in Saudi Arabia. The crane completed its first of several major lifts in early 2009 at the plant in Jubail – a 69 metre long depropaniser column weighing 755 tonnes. Working at 84 metres radius, the AL.SK90 allowed engineers to complete foundations and pipe racks in advance of the column installation.
In addition, with a little modification – basically just widening the base, the crane’s capacity can be increased to 5,000 tonnes, making it an AL.SK120. The crane can also be equipped with a standard hoist system for lifts up to 600 tonnes, while strand jacking is employed for the heavier loads.
ALE began the design in December 2006 after the major crane companies showed no interest in such a crane. By the end of 2007, fabrication work involving 65 companies from around the world had begun with the launch less than a year later when it was lifting 3,000 tonnes at 31.5 metre radius on a 130-metre main boom. Other tests completed includes 1,500 tonnes at 69 metres and 540 tonnes at 114 metres radius.
The original name of the crane was changed from AL.SK90 to AL.SK190, which figure 190 indicates the crane’s maximum load moment of 190,000 tonnes/metres.
The transportation concept is similar to Mammoet PTC series ring-type crane which can be fitted in standard shipping containers, which double as ballast boxes. The ring is set up in sections rather than an entire ring and can move around either using rails or self-propelled modular trailers.
Mammoet unveiled plans for its Platform ringer Twin boom Containerised crane, the PTC120DS (PTC140DS) and PTC160DS in the 2009 summer as well.
First Lift in North America – AL.SK190 carried out its first lift in North America which the crane was used to replace 6 new coker drums weighing up to 471 tonnes each. The crane first lifted a 1,400 tonnes derrick structure which was positioned on top of existing coker drums at a height of 100 metres and set on the ground. It was the 4,300 tonnes crane first time complete derrick assembly consisting of triple drill towers and cutting deck removed and replaced in a single piece. As the lift requires complex tackle arrangement with 12 point pick up, only AL.SK190 is possible to do the job.
First Lift in Turkey – Together with Turkey-based crane company Izmir Vinc, ALE used AL.SK190 to upright a 600-ton vacuum tower and an 800-ton crude column, lifting the load over a 20 metre high pipe rack at the Greenfiled petrochemical site in Aliaga, Izmir province. The tallest item measured over 80 metres in height.