4 minutes | magazine 02/2021
“We’re glad we could help”
Uwe Langer is an acknowledged expert when it comes to particularly tricky hoisting work. The boss of crane and heavy haulage contractor Riga Mainz and his team have managed to meet a whole series of challenges by developing several new or particularly smart solutions.
Power Lift Tower meets Power Lift Crane
His latest baby is the PLT. It stands for power lift tower. And they can really move things. But what effect do the towers have on the heavy haulage vehicle that they operate from? To find out, Langer needed some serious support – so he called us. Would we be able to help? Of course we would. And we did. And we were delighted to do so!
Expert for tricky hoisting work – Riga Mainz boss Uwe Langer.
A little while later Uwe Langer then drove into the yard with five of his eight towers and a 22-axle SPMT (self propelled modular transporter). He parked everything at the Liebherr acceptance site between the LR 13000, which was fortunately at the test site at the time of his telephone call, and 1250 tonnes of test weights. These were attached to the hook of the 3000 tonne crane. For the load test, two PLTs are placed on the concrete floor and three are evenly spaced on the SPMT.
The entrepreneur from Mainz explained his latest idea which he had had built by Neuenstein-based Greiner: “Each power lift tower can hoist 500 tonnes, so with eight hydraulic lift towers we have a total of 4000 tonnes of hoisting power. The synchronous hoisting by the towers, which are operated using a standard site electricity supply and a wireless remote control, is controlled electronically.” He is also proud of the fact that the hoisting height can be increased using stacking elements and that neither hydraulic hoses nor additional power units are required. “And, of course, each PLT is completely autarchic.”
Five power lift towers and a 22-axle SPMT stand ready for a static load test.
In the dynamic load test, the PLTs had to raise the 1250 tonnes all on their own.
The thing that Langer does not yet know and wants to test is what happens to the SPMT when a load is placed on it in a specific position. He knows the theory thanks to simulations and calculations. But is that really what would happen in practice? To find out, he needed around 1200 tonnes of test weights and a crane for hoisting.
No problem – his call to Liebherr was all that was required. We had an LR 13000 at the acceptance site (the sixth so far, by the way) and we also had plenty of test weights. And there was no shortage of motivation on the part of our colleagues at the site – we firmly believe in developing close partnerships and we know that this has led to many products and processes being improved.
PLTs on SPMTs move prefabricated bridge components weighing up to 1850 tonnes to their final position in their first job.
And so the trial was made possible by collaboration and produced some pleasing findings. Firstly, the deformation suffered by the SPMT was significantly less than forecast, resulting in a high precision of the towers in the vertical. And then secondly, the synchronous operation of the lift towers ran like clockwork. The end result as far as we are concerned is that working with our customers is actually great fun and brings benefits to both of us. So all that remains it to wish full power to the tower!
This article was published in the UpLoad magazine 02 | 2021.
