3 March 2005

BAE Systems and Orion Bus Industries announced they completed the delivery of the first 125 diesel-electric hybrid buses for MTA New York City Transit and has begun delivering the next set of 200. If the deliveries are on schedule, by the end of 2005 the MTA transit will operate 325 hybrids—the world’s largest fleet of hybrid electric buses.

The MTA started tests with a fleet of ten Orion VI hybrids in late 1998. The order for the 125 Orion VII buses was placed in 2000, and was filled during 2004. By now, the MTA has accumulated about two million miles of revenue service with hybrids.

The buses utilize the HybriDrive™ series hybrid propulsion system by BAE Systems. The system propels the bus with a single electric motor that is powered by a diesel-driven generator and an energy storage unit. The system benefits are:

  • A smaller engine compared to that used in conventional buses, which runs at optimum speed for clean operation and efficiency.
  • Quicker acceleration and a quieter ride.
  • A regenerative braking system to save energy (MTA recorded a fuel consumption reduction by 40% relative to standard diesel buses).
  • Reduced maintenance on brakes (the brake life was about doubled due to the regenerative braking) and transmission (which is eliminated in the series hybrid).

The Orion VII HybriDrive buses are powered by a 5.9-liter, 260 hp (194 kW) Cummins engine with a 120 kW traction generator and a 250 hp (186 kW) traction motor.

In total, MTA operates a fleet of more than 4,000 buses, this number including 481 CNG fueled buses.

Another order for Orion/BAE hybrids came from the Roosevelt Island Operating Corp. of the State of New York, who will receive four Orion VII hybrid buses for use in the island’s transit-bus fleet. The buses are scheduled for delivery in 2006.

The largest fleet of hybrid buses of over 200 vehicles is currently operated in Seattle, WA. The Seattle buses, manufactured by New Flyer, feature the parallel hybrid powertrain by GM’s Allison Transmission and are powered by Caterpillar C9 ACERT engines.

Source: BAE Systems (press release)