19 January 2000

MTA New York City Transit has ordered 125 buses equipped with a hybrid electric drive system designed to reduce emissions and fuel consumption while improving performance and reducing maintenance costs.

The order represents the mass-transit industry’s first large-scale purchase of hybrid buses and follows more than a year of technology demonstration by New York City Transit, which has operated a five-unit test fleet since the fall of 1998. The New York demonstration fleet has logged more than 100,000 miles, mostly on congested Manhattan routes.

Orion Bus Industries of Mississauga, Ontario, will build the buses, which will be based on a low-floor platform similar to those used in the demonstration fleet. They will be delivered in early 2001.

“We are very impressed with the performance of these vehicles and excited about the future of hybrid as New York deploys more clean-fuel buses,” said Lawrence Reuter, president of MTA New York City Transit. “These buses offer an impressive combination of environmental, cost and performance advantages we have not seen from other alternative fuels.”

The buses will be equipped with the HybriDrive™ propulsion system, produced by Lockheed Martin Control Systems. The system propels the vehicle with an AC motor powered by a diesel-driven generator and batteries that are recharged continually as the bus is driven. The diesel engine is smaller than that used in a conventional bus and operates at nearly constant speed, so it is more fuel-efficient than a standard bus and produces a fraction of the emissions.

According to Lockheed Martin, the hybrid system produces half the nitrogen oxides and 98% less carbon monoxide than buses fueled by compressed natural gas, while producing about the same amount of particulate matter and delivering twice the fuel economy.

“Diesel hybrid is an exciting technology that has the potential to become a significant part of our efforts to reduce bus emissions,” Reuter said. Another attractive feature of hybrid buses, he added, is that they do not require special fueling equipment and other costly depot modifications, as CNG buses do.

“We are extremely pleased that New York City Transit has demonstrated its confidence in our technology,” said James Scanlon, president of Lockheed Martin Control Systems. “A number of other transit agencies have expressed interest in our HybriDrive™ system, and we're looking forward to supplying these systems that not only provide economic benefits, but also improve our environment.”

Lockheed Martin said the hybrid configuration has been designed to offer operators the following other advantages:

  • The motor that propels the vehicle is connected directly to the drive wheels for faster, smoother acceleration compared to a diesel engine coupled to a mechanical transmission. Eliminating the transmission also eliminates costly maintenance and overhaul.
  • Because the engine does not constantly rev up and down like that in a conventional bus, it needs less maintenance.
  • The buses run quieter than a conventional diesel, a difference immediately evident to New York passengers.
  • A “regenerative braking” system reverses the motor's magnetic field during braking to slow the vehicle, generating additional electricity to charge the batteries and reducing brake wear.

Source: Lockheed Martin Control Systems