Liebherr unveiled three new cranes at its ‘2012 Customer Days’ event at Ehingen manufacturing facility in Germany.
This is the fifth such event held at Ehingen – starting in 1999 – and it attracted more than 1,800 visitors from all over the world on each of the two days.
The new cranes included the 750 tonne LTM 1750-9.1 All Terrain, the 220 tonne LTR 1220 telescopic crawler and the ‘flagship’ crawler crane – the 3,000 tonne LR 13000. Visitors were also treated to visits around the whole manufacturing site as well as equipment demonstrations and a spectacular firework/laser show finale.
The extensive testing of the LR 13000 is now completed, with the first machine sold to Mammoet and currently being shipped to a refinery contract in the USA, the second LR 13000 had to be made ready to be the centre-piece of the ‘four crane mobile’ in which the LR13000 lifted an LR11350, with an LR1350/1 on its hook, which in turn was lifting an LTR1100.
Liebherr also briefly talked about other cranes under development including a new crawler crane in the 1,000 tonne class to fit between the LR 1750 and the LR 11350, which is scheduled to be presented at Bauma 2013. Also to be shown at Bauma is a new five axle MK - the successor to the MK 100 mobile tower crane. A six axle long boom LTM crane is currently in development and it is also thought that a long boom 60 tonne capacity AT crane is also on the drawing board.
The highlight of the machine demonstrations was the LR 13000 lifting the three smaller cranes. This particularly tricky lift was the brain-child of Hans-Dieter Willim, Liebherr’s chief crane designer. The LTR 1100 weight 62 tonnes was the first to be lifted by the LR1350/1 and raised to a height of about five metres which meant that after all the lifts it would be at a height of about 20 metres.
The LR 1350 was equipped with a 30 metre main boom and lifting the LR1100 at a radius of 10 metres. The radius was chosen so that the joint centre of gravity of the LR 1350 and LTR 1100 was exactly at the centre of rotation of the LR 1350. Including counterweight and slings the LR 1350 weighed 288 tonnes making a combined load of 350 tonnes for the LR11350 to lift.
Two holding/guy ropes were used – attached to telehandlers – to stop the cranes swinging backwards and forwards in the wind. The LR 11350 then lifted the two cranes at a radius of 14 metres - 75 percent of its maxium capacity at that radius. The centre of gravity was located at a height of 8.2 metres.
Finally the LR 13000, fitted with a 108 metre Power (P) boom lifted all three cranes - with a combined weight of 1,430 tonnes, at a radius of 30 metres. The crane has a capacity of 1,521 tonnes at that radius and was therefore at 94 percent of its capacity.
The centre of gravity for all three cranes lifted was at a height of 18.3 metres. In order to ensure the lateral stability Liebherr used extra long rods connecting the cross head and the hook.
In this set up the LR13000 weighs 2,170 tonnes which includes 400 tonnes of basic counterweight. At a radius of 30 metres the load of 1,430 tonnes is almost in balance with the derrick counterweight which weighs almost 1,400 tonnes and was suspended at a radius of almost 30 metres. The combination of counterweights, base machine, booms and load meant that a total weight of 5,000 tonnes was applied by the LR 13000 crawlers to the concrete base.
The centres of gravity and weights of all the cranes had to be calculated very accurately as any deviation would immediately have affected the working radius of the crane lifting triggering a chain reaction.
The cranes and hook were then rotated by two telehandlers, even with the hooks roller bearings the rear telehandler had to apply a force of one tonne at a 5.5 metre radius. In additon to their role of turing the load, the telehandlers also provided some protection from lateral winds.
The LR13000 was then able to slew the load smoothly as both the counterweight and three crane load were in balance. To end the demonstration, the LR 13000 then tracked – very slowly - with its 5,000 tonne applying a ground pressure of only 70 tonnes per square metre. Additional mats could be used to reduce this to 30 tonnes a square metre.
The LR 13000 has a maximum load moment of 65,000 tonnes, maximum under hook height of 246 metres and maximum radius of 160 metres - When fitted with a 120 metre main boom and 54 metre luffing jib - at which it is able to lift 316 tonnes. However if the P boom is used it can lift 586 tonnes an increase of 85 percent – thanks to the P booms increased lateral stability.
Ehingen is the world’s largest production facility for All Terrain cranes, covering an area of 840,000 square metres with 220,000 square metres of buildings. The facility employs 2,800 and according to Liebherr has a market leading 44 percent share of the All Terrain market. Despite the recent global economy Liebherr-Werk Ehingen has grown streadily over the past 10 years and achieved revenues of almost €1.5 billion.
Deliveries this year should total around 1,450 cranes – up on the previous year. Eight years ago more than 60 percent of the revenues came from Western Europe, with Germany the main market. Last year it was less than 40 percent.
Investment in the facility continues with €30 million planned for 2012. Currently under construction is a new hall – 120 metres long by 90 metres wide - in the northern part of the plant to handle special projects as well as for testing.