Electric crawler cranes new from Liebherr

In an online global launch on 1 December Liebherr announced a pair of new crawler cranes powered by electricity.

Two models are available, the 220 tonne capacity LR 1200.1 unplugged and the 250 tonne capacity LR 1250.1 unplugged. Unplugged in the model nomenclature indicates electric power – in this case either from a mains cable for stationary operation and charging, or from a set of lithium-ion batteries allowing untethered free movement and full operation of all functions. Electric cranes produce no pollution at the point of use, are quieter than their diesel counterparts and need less maintenance.

Gerhard Frainer, managing director, sales at Liebherr-Werk Nenzing, said, “Especially the year 2020 has shown that one must be open-minded and bold to break new ground. With our unplugged cranes we offer our customers an alternative drive design. As we have already seen with the LB 16 unplugged, the first battery-powered drilling rig, the strategy is a complete success. Strict requirements regarding environmental sustainability in tenders for construction projects increase the demand for advanced technologies. For us, it was clear that we extend and successfully establish the design in further product groups.”

Liebherr has calculated that over an operating period of 10,000 hours, the new electric crane will have eliminated consumption of 70,000 litres of diesel and reduced carbon dioxide emissions by 180 tonnes. The lithium ion battery is 95 % recyclable, the company said.

The new cranes were developed in-house by Liebherr-Werk Nenzing (LWN) in Austria, with the assistance of external engineering specialists. They are fully tested and ready for production. This size of crane was chosen because it is a popular capacity class, especially in urban applications, where the advantages of electric cranes are particularly beneficial.

Orders have been received for the new models and the first unit delivered, of the 250 tonne model, was to crane rental specialist Kynningsrud in Norway. The first unplugged unit for the UK goes to Select Plant, the construction equipment arm of Laing O’Rourke. It will also be the 250 tonne capacity model and will be delivered in March 2021. It will expand the fleet, supporting the pipeline of major infrastructure works in the UK, the company said.

Alternative energy

Structurally the new cranes are based on the existing diesel versions, as LWN explained. “Our main goal was not to develop a new crane, but to be able to offer the extremely successful diesel version as an electric version as well. So, if the customer decides to buy the electric version, he will buy a crane with all the previous advantages plus the extended advantage of zero emissions.”

As such the new machines use 255 kW electric motors as part of a 700 Volt DC electrical system instead of a diesel engine to drive the hydraulic pumps to power the crane mechanisms and track drives. A lithium ion battery sits in the space otherwise occupied by the diesel engine. The batteries are included in the purchase price and are not rented separately as has been the case with some electric cars.

So-called range anxiety, also familiar in the context of electric cars, is not an issue, LWN explained, “When plugged in, full power is available throughout the day. In the unplugged state, the crane can be operated for four hours. On request, the unplugged performance can be increased by up to 33 % with the help of a larger battery.”

According to the amount of site power available the recharging time from discharged to fully charged is as follows: with a 32 Amp supply: 9 hours; with a 63 Amp supply: 4.5 hours. As an option, a 125 Amp charger is available which takes just 2 hours and 15 minutes.

In terms of lifting capability, how do the charts compare with those of the diesel versions? Liebherr said the LR 1200.1 unplugged has the same load charts as the diesel version –  even slightly better than those of the diesel version, because the small extra weight of the batteries acts as additional central ballast.

It is the same story for hoisting speed, slewing speed, and other mechanisms’ performance. Liebherr said the performance as a whole is almost identical. “The direct response of the electrical system gives the driver the impression that the movements are sometimes faster, which is true. Sometimes we even had to reduce the speeds. Drivers perceive the direct response behaviour as an operating advantage,” a Liebherr-Wek Nenzing spokesperson said.

On the subject of price, it costs more to buy than a diesel version but Liebherr said it has worked hard to keep that extra to a minimum. In addition to keenly observing developments in this sector, ICST looks forward to a wider application of electric drive technology, in the form of new electric wheeled mobile telescopic cranes, telescopic boom crawlers, rough terrains and truck mounted cranes. More information on these new cranes is published in the next issue of International Cranes and Specialized Transport magazine and in our online feature at www.khl.com soon.