15.04.2009

Liebherr LTM11200-9.1 tandem lift

Two 1,200 tonne Liebherr LTM 11200-9.1 All Terrain cranes owned by Dutch lifting specialist Mammoet, have teamed up for a tandem lift in Germany.

The two cranes came together for what is possibly the first LTM11200 tandem lift, in Cuxhaven, North Germany. The local Mammoet team from Leuna, assisted by the company’s head office in Schiedam, Holland, planned five large tandem lifts to erect a portal crane with a total weight of 1,000 tonnes.
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The two Liebherr LTM11200-9.1's lift one of the two beams weighing 250 tonnes, into place.

The massive crane will be used by Cuxhaven Steel Construction to build a new type of foundation system for offshore wind farm turbines. The new foundation design, called a Tripile is a three legged concrete and steel structure weighing 490 tonnes. Lighter and more compact than the usual monopile foundations.

A team of six with headed by Gernot Öder of Mammoet Germany arrived on site a week prior to the two cranes, in order to prepare and plan the series of lifts.

Each of the five lifts had to be carried out from different positions involving four relocations following the initial set up. The fact that the LTM11200 can travel with a large portion of its counterweight in situ (30 tonne axle loads) helped save time and effort, allowing the job to be completed in a single day.

The heaviest lifts were the two bridge beams, each weighing 250 tonnes and measuring almost 70 metres long by five metres high, which had to be lifted to over 40 metres. However this was a relatively simple tandem lift compared to placing the trolley and machinery house.

The 30 by six by six metre trolley weighed 155 tonnes and had to be lifted to a height of 50 metres, turned through 90 degrees and then placed on to the two crane bridges.
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The most challenging lift, placing the 155 tonne trolley/machinery house on top of the crane

With one crane having to lift over the crane structure at a radius of 23 metres, it was decided to rig it with the shorter 50 metre main boom plus 30 metre luffing jib. The other crane was simply rigged with the longer 100 metre main boom and Y- Suspension system and 52 tonnes of counterweight (The maximum with which the crane can ‘walk’)

With just three metres of boom clearance and increased wind speeds forecast the last lift was a delicate task. However the load was successfully lifted turned and placed precisely on the crane.

After the lift Öder commented: “Up to now I can only speak good about this crane. It faultlessly fulfilled the load parameters and we were able to complete the erection in Cuxhaven in just a day. A strong piece of equipment!“