When tasked with lifting 20.4 t components up to 62 m to erect a 25 t capacity Potain MDT 569 tower crane for the Karlsruhe Institute of Technology’s new city center laboratory construction project, Spira called on fellow German rental company Bott’s 400 t six-axle Grove GMK6400 all-terrain crane to get the job done quickly and efficiently.
Potain tower cranes are world-renowned for their quick and easy assembly no matter the jobsite complexity. They are designed to be transported in as few containers as possible, many elements can be preassembled, and the Manitowoc CCS (Crane Control System) reduces configuration time from more than three hours to just 15 minutes.
This incredible efficiency seems hard to beat but it can be increased even further by using a Grove all-terrain crane to erect and/or dismantle the tower crane.
Working together, Potain and Grove cranes save time and money – a fact which German rental company Spira took into full account when tasked with erecting one of its Potain MDT 569 tower cranes to help construct a new laboratory for the Karlsruhe Institute of Technology (KIT).
KIT is situated in the city center and access to the jobsite was constrained by a narrow driveway close to tram tracks. Assembly of the tower crane needed to take place as quickly as possible to minimize disruption to the ring road traffic – and using a mobile crane that was narrow enough to navigate the confined site and strong enough to lift all the elements of the 25 t capacity tower crane. The heaviest component was the 48 m boom section, which weighed 20.4 t.
To complete the job in just two days, Spira called on the support of fellow equipment rental company Bott, which boasts a powerful yet compact 400 t six-axle Grove GMK6400 all-terrain crane in its fleet of 40 cranes including 23 Grove all-terrain models.
“The Potain MDT 569 is one of the few topless cranes in the 25 t capacity class – and the optimized size of the crane components for truck transport, ease of installation and ergonomics of the assembly were ideal for this job to construct a new laboratory,” said Yves Dupré, who is joint manager of Spira along with his brother Philippe.
“For a week, we meticulously planned the pre-assembly and logistics together with Bott and we were impressed by the relatively compact size of the strong 400 t Grove machine, as well as the speed and ease with which it was set up and lifted all the elements of the Potain MDT 569,” Philippe Dupré added.
The Grove GMK6400 all-terrain crane provides long reach and strong lifting capacities in a compact package, enabling it to access, maneuver and carry out complex lifts on even the most confined inner-city jobsites. The optional MegaWingLift provides rigidity when working with long boom/jib/counterweight combinations to increase the load chart on the main boom on the luffing jib.
Daniel Matheis, who is responsible for operational planning at Bott, said: “For us, the Grove GMK6400 has been a pleasure to work with ever since we acquired it as a used machine from KranAgentur Werner in April 2020. It has the best load charts in its class, combined with small outrigger base dimensions and fast set-up times. We often use it in place of a seven or eight-axle crane, which helps to save time, money and effort.”
The Grove GMK6400 has a 60 m main boom and up to 79 m of luffing jib available, giving it a maximum possible tip height of 136 m and the ability to handle loads out to a maximum radius of 96 m. When combined with the patented self-rigging MegaWingLift, the crane’s capacity on the main boom is increased by 70% (e.g. lifting 64 t on a 60 m main boom) and by up to 400% when using a luffing jib.
On the KIT jobsite, the Grove GMK6400 was configured with 20.3 m of main boom, a 55 m luffing jib and 115 t of counterweight to give a maximum load capacity of 19.4 t within a 48.8 m radius. In just one and a half days, the compact 400 t all-terrain crane was rigged, did the job, was disassembled and left the confined jobsite, saving the customers time, money and effort.
The Grove GMK6400 helped install the Potain MDT 569 to a hook height of 48.9 m with 60 m of jib from which it can lift 8.9 t at the tip. The customer’s requirements included being able to lift elements from 15 t at 35 m and 8 t at 60 m.
The tower crane will remain on site for 17 months where it will handle large, prefabricated components to construct two buildings – one with six floors and the other with two floors. Once complete, Bott’s Grove GMK6400 will return to disassemble the Potain MDT 569 as quickly and efficiently as it assembled it.