Initiatives in the field

The first hybrid dump truck

Hybrid gas-electric vehicles have already proven their effectiveness in reducing fuel consumption and limiting greenhouse gas emissions. However, until now, this has been difficult to achieve with diesel engines. It is with this aim in mind that Colas and Renault Trucks entered into a partnership to further the development of the only French dump truck prototype currently in use with a hybrid propulsion system (diesel + electric). Both the Chairman and CEO of Colas SA and the Chairman of Renault Trucks were on hand to witness the delivery of this first prototype to Colas Rhône-Alpes on September 15, 2009.

The foundation brakes and retarders on conventional trucks convert the vehicle's kinetic energy into heat that is released into the atmosphere, accompanied by brake dust, from brake pads and shoes, as well as fine metal particles. With the parallel hybrid system, the vehicle's braking energy is recovered to be converted into electricity and stored in batteries. Once the vehicle has come to a complete stop, the diesel engine turns off automatically. When the vehicle is put back in motion, it is powered uniquely in its electric mode (without noise or pollution) until it reaches about 20 km/h, at which point the diesel engine automatically takes over. Diesel mode is only used during the phases when it consumes the least energy, and thus not for starting up and accelerating after braking.

No more noise, exhaust gas or vibrations at red lights! This vehicle is ideally suited to urban and suburban environments (pending the availability of all-electric vehicles). It is more pleasurable to drive and a real boon for residents as well. Measurements carried out over the first 4,500 kilometers in standard use point to fuel savings of about 24%. Easier to handle and less noisy, the vehicle offers a very comfortable and effortless driving experience thanks to its robotic transmission. At the premises of our clients, the vehicle's noiseless maneuvers raise eyebrows and invariably lead to a flurry of questions. At this stage, the prototype only has the status of an "exploratory, experimental investment," but is expected to be followed by more extensive development in the years to come.

Credits photos: Renault Trucks

Download the pdf file