The Airport Technology division of Goldhofer AG is equipping its zero-emission SHERPA E cargo and pushback tractors and its PHOENIX E towbarless aircraft tractor with battery-powered motors and inverters supplied by ARADEX AG of Lorch, Germany. For airport operators, ground handlers and airlines, this solution is the key to extremely economical and environmentally friendly baggage and cargo transportation on the apron and aircraft handling with a maximum take-off weight of up to 352 tons. The electric powertrains developed by ARADEX have been designed in the framework of a partnership with Goldhofer to meet the specific requirements of airport operations. They offer very high torques as well as balanced and finely tuned power transmission. The compact power packs are mounted directly on the axle and do not require a gearbox. This saves space and weight.
Productive Collaboration
Goldhofer began developing battery-powered towbarless aircraft tractors back in 2014. ARADEX AG, which is located only 120 km from Memmingen, was already noted for its years of experience with electric commercial vehicles. The company’s portfolio at that time included electric powertrain solutions for trucks, mining vehicles and ships but not yet for cargo and aircraft tractors. Since electrically powered ground handling vehicles also have to meet extremely strict specifications in terms of function and safety, intensive and constructive cooperation between the two companies was called for. Goldhofer presented its first SHERPA E at Inter Airport Europe in 2017.
“At airports around the world, cargo and aircraft tractors have to satisfy extremely tough requirements each and every day. This also applies to electrically powered vehicles. I am all the more delighted therefore that, together with Goldhofer, we have succeeded in optimizing the configuration of our high-torque drive train so that it is not only very robust but also ensures reliable and balanced towing operations with maximum sensitivity and control,” says Thomas Vetter, founder and member of the executive board at ARADEX AG, with regard to the results of this successful partnership.
The same view is expressed by Lothar Holder, member of the board at Goldhofer AG and Head of Airport Technology: “Together with ARADEX, we have developed a highly sustainable and perfectly tuned powertrain solution for our fleet of electric tow tractors. It not only provides enormous power but also develops and delivers it finely controlled.”
High Performance, Smooth Power
The newly configured electric powertrain is used in both the SHERPA E and the PHOENIX E. Together with the inverter, the electric motor is mounted directly to the axle. The finely tuned system ensures impressive and at the same time smooth power transmission without the need for a gearbox.
“This is the key to a design with compact dimensions and low deadweight,” says Vetter.
The result is a torque of up to 1,200 Nm in the case of the SHERPA E and no less than 4,000 Nm in the case of the PHOENIX E delivered to the drive axle with maximum control. This means all standard passenger and cargo aircraft with up to 352 t MTOW, such as the B777, can be moved quickly, safely and above all with zero emissions. With the PHOENIX E, the finely tuned ARADEX powertrain offers additional benefits: With the aircraft nosegear piggybacked on the towbarless tractor, the precision-tuned power transmission ensures optimized and safe traction and braking.
After numerous studies and extensive testing – including at Zurich, Munich and Los Angeles airports – it was clear that emission-free apron handling with the SHERPA E and PHOENIX E is both technically feasible and cost-effective. The successful development work was well noticed.
Holder says, “Since 2019, more and more of our cargo handling customers have been opting for the extremely high-performance solutions integrated in the SHERPA E. Demand is increasing at a fast pace. Also, with the delivery of the first PHOENIX E to our customer Lufthansa/LEOS in December 2021, Goldhofer’s battery-powered solution with ARADEX drive trains is demonstrating its performance capability and efficiency – also in the context of the demanding operational profiles of towbarless towing – and setting the benchmark in this market segment.”
