Electric bus set for street trials

ARMED with a whopping 21,000Nm of torque, Australia’s first locally designed, locally built all-electric urban bus prototype was completed this week, in time for planned shake-down trials starting on the Gold Coast next month.

Queensland-based bus design and manufacturing operation Bustech – a division of Queensland’s biggest bus company Transit Australia Group – has already signed a contract to supply electric buses for a Malaysian government’s planned $170 million electric bus system.

Bustech already builds up to 250 diesel buses a year at its Burleigh factory, supplying single and double-decker buses across Australia, including Queensland where its parent company runs a fleet of more than 650 urban buses on government routes in towns and cities between the New South Wales border and Cairns.

The electric bus – revealed at a recent bus show in Victoria – was designed from the ground up by Bustech in collaboration with the government-backed Automotive Co-operative Research Centre (AutoCRC), the CSIRO, Melbourne’s Swinburne University and the Malaysian government.

Bustech claims that while the electric bus will cost customers about the same price as a conventional diesel bus, the electric drive system will be up to 80 per cent cheaper to service over its lifetime.

German company ZF supplied a range of components for the electric bus prototype, including the drive system that involves a pair of electric drive axles, each with a water-cooler electric motor producing peak torque of 10,500Nm for a total of 21,000Nm – ideal for stop-start urban routes.

To put that in perspective, Mercedes-Benz’s passenger-car torque champion, the twin-turbo 5.5-litre V8 S63 AMG L, produces 1000Nm, while a Kenworth road train prime mover can produce 2779Nm. The Army’s gas-turbine M1 Abram’s tank pumps out 3754Nm.

Each electric motor on the bus produces 120kW of power for a total of 240kW, and incorporates regenerative braking to top up the batteries in city service.

The 50-plus-passenger bus is said to have a range of up to 300km on full charge of its batteries. Power drawn for the air-conditioning system reduces range to about 200km in a hot climate like Malaysia’s, but Bustech says it is working on systems to improve air-con performance.

To service the Malaysian contract, Bustech has signed a memorandum of understanding with Malaysian vehicle assembler Go Automobile Manufacturing – builder of Great Wall Motors vehicles in its home market.

ZF Services – best known for its automatic transmissions employed by many car companies such as BMW, Jaguar, Volvo and Ford – already supplies a number of components for existing Bustech models. These include transmissions, axles, steering and suspension systems.

ZF Services Australia OE (original equipment) business manager Gary Bain said on Wednesday that Bustech and its partners had completed the prototype build this week.

“The all-electric bus ready for the market place,” he said.

The ZF electric drive units – suitable for both full electric and hybrid vehicles – not only include the motors but also the wheel bearings, disc brakes, axles and seals in a single unit.

Because the electric bus’s axle-mounted motors do away with the bulky diesel engine at the back, Bustech was able to re-design the floorplan.

The prototype shown at the bus show at the Melbourne Exhibition Centre was decked out as a luxury tourer. It included innovations such as touchscreen control the driver, LED lighting, and all-electric doors, electric air-conditioning and rearview cameras in place of mirrors.

The battery pack can be removed and replaced when newer, more efficient batteries come on the market.