In real-world trials for MAN electric buses in and around Hamburg, the Conti Urban HA3 tyre from Continental has helped shape the data in developing electric local public transportation.
Hamburg Plans an Electric Future for Its Bus Fleet
For local transport operators Hamburg-Holstein GmbH (VHH), the switch in 2020 to procuring exclusively zero-emission vehicles for its bus fleet was very much about the future potential of solely electric vehicles. The company’s elexity brand brings together all aspects of sustainable mobility – from new depot infrastructure to electric mobility. Currently, VHH has 32 electric buses with plans to double that number by 2021, with ambitious plans to convert the entire fleet to zero-emission drivetrains between now and the following decade. MAN has been instrumental in VHH’s change to zero emissions, with the introduction of the Lion’s City bus, which has an electric motor and energy supplied by battery modules with a capacity of 480 kWh.
Continental Works Towards VHH being Carbon-Free
To ensure the tyres are adapted to the weight of MAN’s Lion’s City buses, Continental has been stepping up the load capacity of the Conti Urban HA3 tyre. This increase in the load index is just one of several criteria that need taking into account electric vehicle tyres. For several years now, Continental has been acquiring valuable experience in real-world tests, such as this one with MAN. The demand for suitable tyres is growing fast, with the 2019 EU Clean Vehicle Directive a crucial reason for the changes across European municipalities.
The minimum targets for CO2 reduction by low and zero-emission buses in local public transport in Germany stand at 45 per cent by the end of 2025 and 65 per cent by the end of 2030. At least half of these minimum targets for urban buses will have to be met by zero-emission vehicles. “Zero-emission” means that they will have to be electric or fuel-cell vehicles that emit less than 1 g CO2/km.
“For several weeks now, the 17 electric buses from MAN have formed part of our first fleet of electric buses, carrying our customers to their destinations in and around Hamburg in an environmentally compatible way,” says Toralf Müller, CEO of VHH. CO2 emissions have drastically reduced, but Müller explains that a core element is the necessary charging infrastructure. “For us as a company, electric mobility is uncharted territory, there are no role models to follow, no ‘copy & paste’ options. Together with our partners, we have to break new ground while keeping a constant eye on the technology, which is progressing so fast.”
How Continental is Paving the Way for a New Electric Age
“Developing a tyre for electric urban buses is particularly demanding in technical terms,” explains Hinnerk Kaiser, head of tyre development at Continental. Tyres for electric buses have to cope with greater loads than their counterparts on buses with combustion engines. At the same time, they need to deliver the same mileage and meet the same safety standards. “Tyres on electric buses are exposed to higher torque when pulling away and accelerating,”
Going further, Kaiser adds that deceleration is a core element to invest in as the power required for the drive axle tyres is substantial. He also adds that for urban traffic, the noise must match the comfort-enhancing benefits of the electric motor.
“Field tests like the one with VHH in Hamburg prove very valuable in terms of experience for us because they help us to develop our tyre lines to meet the needs of the new electric buses and trucks,” concludes Hinnerk Kaiser.