Project: Whisper city busses, Apeldoorn

The city of Apeldoorn is test track for future of city bus technology - without any noise and pollution in the inner city. While saving up to 50% fuel, Whisper buses help the city of Apeldoorn to meet strict air quality regulations. And e-Traction thankfully gains the opportunity to test and demonstrate TheWheel^® SM500/3, our new in-wheel direct drive. Key advantages with TheWheel^® and the e-Traction system^®:

• A Whisper bus is 50% more fuel efficient compared to the standard diesel equipped bus
• A Whisper bus sustains extended zero-emission driving - key in achieving inner city emission standards.
• A Whisper bus is silent and keeps the inner city free of motor noise 

News and Events

May 2011

Project Whisper will be presented at Eindhoven University of Technology during the 'International Automotive Congress'. This date is also the formal closure of the project. We welcome you to take a drive in our Whisper buses at the Congress, May 16.

January 2011
Project Whisper is being continued in 2011 with two busses! At this moment, the Whisper is entering its second phase. With updated exterior in upholstry of transport corporation 'Syntus', the first green coloured Whispers will operate in Apeldoorn around spring 2011.

What makes the Whisper a revolutionary bus concept

Motor drives, axle and suspension
TheWheel^® is the core of the impressive energy efficiency of the Whisper; it saves up to 40% compared to an ordinary EV drive line. For more information see our TheWheel overview section

Energy storage and supply
The next step in transition is adding an energy buffer. As described in the e-Traction system section Li-Ion batteries are installed. The capacity of this buffer allows zero-emission electric driving up to one hour of operation.

Range extender and auxilliaries
A well designed buffer allows the use of a smaller power source. Every Whisper bus is equipped with a small diesel generator. Its size is comparable to a small SUV motor as is its fuel consumption.

The Whisper (and TheWheel^®) in action

In the film below you'll see the Whisper bus performing a test. For this test we've placed a camera underneath the bus next to one of the TheWheel^® SM500/3 motors.

Testing the Whisper