Diesel engines are still the norm everywhere, not only for all kinds of trucks, but also for Trailer Refrigeration Units (TRUs). Since 2012, Schmitz Cargobull offered its own cooling engine, as an alternative to the widely known TRUs of Thermo King and Carrier.
The German trailer builder opted to build its own TRU to take full responsibility within the Chain of Responsibility and to offer a complete solution. The package includes the trailer, axle, telematics and the TRU. Also, Schmitz Cargobull sought to close the data-chain at the same time.
The Schmitz Cargobull TRU is already proved and known in the business but the attraction is the operation of the whole trailer, which can be done from an app, and the registration of the temperature inside the trailer at all times.
Enter the electric engine
At the 2018 IAA Commercial Vehicles Show, Schmitz Cargobull unveiled its fully electrical TRU without a combustion engine. The maximum cooling power of this system is 16kW at 30°C ambient and 0°C setpoint temperature, the heating power of the machine is little more than 9 kW. The batteries feeding the system are located in the landing legs of the trailer. Their power is roughly 65 kWh at maximum. Before operators buy a trailer with such an engine, a lot of homework needs to be done, to make sure that the electric engine works when it should, which means that batteries have to be loaded every now and then.
Axles and allies
In 1996, Schmitz Cargobull decided that it would produce its own axles, instead of purchasing them from equipment specialists like BPW and SAF-Holland. Slowly but steadily, the Rotos axles of Schmitz Cargobull gained market share all over Europe. Now, Schmitz Cargobull says that 85 per cent of all of their trailers leave the plants on Rotos axles.
Combining the developments of the cooling engine and the customers wish for an emissions free, stand-alone refrigerated trailer, development of an e-axle, generating electrical power during braking, began.
The Germans point out that with this axle, the cooling engine remains silent at all times. Loading the batteries takes much less time as the e-axle recuperates energy and charges the battery. All data will be integrated in the Smart Trailer data-system of Schmitz Cargobull. All responsibility and liability stay with Schmitz Cargobull as well. During the trip, batteries are loaded. Once parked, even during a longer time, the machine can be fed from the grid via a plug. Maintenance costs will come down, oil is no longer needed.
Schmitz Cargobull plans a field test with customers starting in Q4 2020. After this round of testing, which will take a year at least, the trailer manufacturer intends to bring the development to serial production.
The EcoDuo transport concept by Schmitz Cargobull – two standard semi-trailers connected by a dolly and towed by a prime mover – was recognised for its efficiency and reduced environmental impact at the 2019 European Transport Award for Sustainability. The EcoDuo vehicle combination can be divided flexibly, for example at national borders, or in defined areas on two prime movers.