New York City’s Metropolitan Transit Authority is planning to increase the size of its diesel-electric hybrid bus fleet.
MTA has ordered an additional 500 Orion VII hybrid transit buses to increase its hybrid fleet to 825 units by the middle of 2007. The agency also retains an option that could add 389 more hybrid buses to city service.
The heart of the Orion VII hybrid bus is the HybriDrive propulsion system, built by BAE Systems of Johnson City, NY, which moves the bus with a single electric motor powered by a diesel-driven generator. A Cummins ISB 5.9-liter diesel, similar to the engine offered in DaimlerChrysler’s Dodge Ram pickup truck, provides additional power that also charges the hybrid system’s batteries.
The batteries are the source of additional electrical power for high demand situations, such as fast starts and hill climbs, said Andreas Renschler, the DaimlerChrysler board member in charge of commercial vehicles. Renschler noted that the diesel engine in a series hybrid like the Orion VII is optimized to run at relatively constant speeds.
“Every Orion hybrid on the streets replacing a diesel bus means a cleaner, quieter environment for all New Yorkers,” said Renschler. “The hybrid system means the diesel engine in each bus is nearly half the size of a standard diesel-bus engine. This smaller engine produces less pollutants and is quieter running.”