Say hello to the pantograph, the ancient device invented in the 1890s that’s currently mounted on e-trucks on test tracks in Germany. Pantographs have been used on trains and trams to connect them to overhead wires, and it’s a key component in the future of road freight. Cable harness experts from inContext are designing the e-trucks’ wiring.
Road freight is increasing year by year with no signs of slowing down. This puts pressure on vehicle producers as well as legislators to cooperate in developing sustainable solutions for road freight. In 2016 Sweden opened the world’s first stretch of eHighway for e-trucks, south of Gävle. Soon afterwards Germany launched an ambitious eHighway project, with Italy following suit, and UK planning a pilot project as well.
Most likely the green truck of the future will utilize a mix of technologies, including battery and hydrogen power, in combination with eHighways allowing the e-trucks to charge batteries while driving.
The e-truck friendly autobahn
5 km of overhead catenary lines are in operation on the A5 south of Frankfurt, one of the most heavily polluted roads in Germany. The catenary cables are supplying electricity to specially designed trucks with a pantograph mounted on top, connecting them to the wires. Additional sections of road are being tested near Lübeck and in 2021 the A5 will be supplied with another 7 km of catenary lines, together with another trial starting in Baden-Württemberg.
A large Scandinavian truck manufacturer has previously provided the project with five hybrid trucks modified with a pantograph. Now seven additional 2nd generation e-trucks are being developed. inContext is doing the tailor-made wiring on these improved vehicles working as a subcontractor.
Key component for e-trucks to succeed
eHighways will probably become the backbone for electrified freight transport by road, and we are really proud of being part of this effort to build a key component of the electrification solution of the future, says inContext engineer Albert Mola.
We’re especially thrilled by the fact that we’re not only doing the design of the cable harness for the e-trucks, but also manufacturing and testing harness prototypes at inContext’s own electrical workshop. In this way we’re taking the solution all the way from design to manufacture.
According to Albert Mola, inContext is working on two different e-truck prototypes:
One is a fully battery powered truck
The other a hybrid truck with batteries as well as combustion engine.
Both have charging capabilities due to their roof-mounted pantograph and with their CCS charging port. This means the truck can charge its batteries while connected to the catenary cables. When leaving the eHighway it switches to batteries or combustion engine.
A tight fit
This is a completely new design compared to the first batch of trucks. They have extra batteries, and the hybrid version can carry a bigger load than its predecessor, Albert Mola explains.
He and his colleagues are facing numerous challenges developing the new e-trucks, which are still in the prototype phase. For instance, integrating the pantograph, delivered by a large German manufacturer, into the existing electrical infrastructure of the vehicle. Also, they have to handle both the high voltage connections going from the pantograph to the batteries and drivetrain, and the conventional low voltage signals flowing through the vehicle, for e.g. CAN communication.
On top of that, we are working under some tight design constraints. For one thing, the modifications we are doing should be minimally invasive, due to production cost. Also, the tower is crowded and contains a large number of components, so there’s not much room for the wiring. Furthermore, the high voltage cables are very stiff with a bending radius that doesn’t allow for much flexibility. So, there is a lot you have to take into account.
From design to workshop
Albert Mola is especially proud of the fact, that he and his colleagues are not only doing the schematics of the cable harnesses for the e-trucks. They are also manufacturing actual physical prototypes at inContext’s own cable harness workshop.
It has been really interesting to align our design group and our manufacturing team. For instance, we’ve created a form board, which is a 1:1 scale flattened representation of the cable harness for manufacturing. It contains all necessary information to build up the cable harness such as length to branch points and all required components.
In this way we can take a new harness all the way from design to manufacture. The next step is to go to the truck manufacturer’s assembly workshop for prototypes to see if everything fits into the vehicle. All this will give us input for the second iteration of the design.
Investing heavily in eHighways
The new prototype generation of pantograph-equipped e-trucks are expected to be released in Q1 2022.
When you look at the current eHighway projects in Germany, UK and other European countries, the demand for trucks with pantographs will be growing, says Albert Mola.
It would make good sense to put them into serial production, and that’s something we would be very happy to see, since we’re part of the prototype concept. Moreover, I believe that overhead catenary lines probably will become an important component of the electrical long-haul infrastructure of the future.
In any case, Germany is investing heavily in eHighways, planning on having between 100 and 300 km operational by 2024, increasing to 4000 km by 2030.