Truck-mounted tower cranes, or mobile construction cranes, as Liebherr terms there, are, in many places, a rare, and often completely absent, crane type. In Cranes Today's hometown, London, they can be seen working in restricted environments, reaching over roofs: our medieval street plan and compact financial district make the most of their key features. But they have not been taken up everywhere.
Aleksandra Meissner, general manager of mobile construction cranes, believes fleet owners are missing out, and suggests 15 to 20% of each crane hire fleet should be mixed with mobile construction cranes.
Meissner's goal, since starting in the role at the start of 2019, has been to persuade customers of the crane's benefits. But finding clever ways for equipment owners to complete jobs is not a new task for her. After starting her career in equipment sales with Hilti, she moved over to Liebherr's in-house Tower Crane Center and later Tower Crane Solutions. This group at Biberach melds crane sales and engineering services, helping customers with tough jobs—like building Europe's tallest tower in Russia, or erecting a crane on Germany's highest peak, the 'Zugspitze'—find not just the equipment they need, but the best way to use it.
It is, Meissner says, "All about speaking the language of the customer. If you listen carefully, and understand the needs of the customers we have the engineering skills." As Meissner speaks six languages, she has a clear head start when talking to global customers.
Meissner traces the development of the mobile construction crane business right back to the start of Liebherr, with the TK 10. Launched in 1949, this was a folding tower on a rail-mounted carrier, that could also be put on tyres: one stands proudly outside the Biberach factory.
It wasn't, she notes, a big seller: "But that's the construction business—sometimes you have to sell the concept." Liebherr's first true truck-mounted tower came with the MK 45. While the TK 10 is a museum piece, some of these are still working, 35 years after production.
Selling this concept has, again, been taking time. "The standard answer," from customers who never worked with a mobile construction crane, Meissner says, "is 'we've never done it like that' or 'we've always done it like this'." The starting point for mobile construction cranes sales is, she says, "The interfering edge: the enemy of the all terrain, is the key selling point for us.
"When our customers have worked with MK cranes they see the advantages. Benefits like working in the night, one man erection, reduced space consumption on the job site and the very silent working with electrical power soon convince."
“Offering a very good service is extremely important for us”, Meissner adds. “This is key for our customers. Here we get a lot of help from our colleagues of Liebherr Ehingen.”
"On the MK 140, you can go up to 65m, reaching over an interfering edge of 35m. You can reach a long way from the centre of the machine, without a Y-guide."
This ability to reach easily over buildings comes with fast set up. The MK cranes can be rapidly erected, within the envelope of the carrier, making it ideal for taxi duties.
"This is how the Dutch use it, three-to-five jobsites a day, to do some special lifts, then move on." But this is not the only pattern of use. "In South Korea, they use it early in the job, for ground preparation, then bring it back for steel work.
"The tendency, as you go into modular construction, is for shorter time on the job site, with less workforce in less space. With this crane, you get exactly this."
In Germany, Meissner says, the crane can be used with a manbasket.
"For jobs like working in a chimney, an additional switch cabinet is available, so you can rescue crew if they have been lowered into an enclosed space. This makes it ideal for jobs in refineries. You also have the option for spark free operation."
While the crane's quick and easy set up and reach over obstacles is key to its use on site, its roadability is also a core selling point. Liebherr's main rival in the segment, Spierings, recently launched a hybrid-power crane capable of all electric transport and operation.
Liebherr's Biberach tower crane factory sources its carriers from the nearby mobile crane plant at Ehingen. Meissner says, "We focused on this as a construction machine, working on the jobsite. The travel is not the main focus, it is not when the customer is earning the money.
"How do we do this, in the world of diesel hydraulics? With a diesel electric concept: drive with diesel, but then plug into 32A (three phase industrial) at the jobsite. The power grid is protected from the crane, and the crane from the grid. While it’s working, you can still hear the birds, it’s near silent.
"We focus on reliability. So we stick to the clean technology of the full electrical operation. But the operator, and the CEO investing in the machine, need to know there will be zero downtime.
"At Biberach, we have 50–60 years of experience with electric power; and at Ehingen, expertise in the diesel carrier." That expertise, combined with the two plants' global parts and service network, gives Liebherr an edge, Meissner believes, in keeping cost of ownership low and avoiding downtime.