King County Metro tests diesel-electric hybrid

Published 11:54 am Thursday, February 21, 2008

King County Metro is test-driving a one-of-a-kind 60-foot hybrid diesel-electric bus throughout the county in the coming weeks, although riders won’t be able to board this bus.

Instead of people, Metro has loaded it with five dozen 40-gallon barrels of water to simulate a full load of passengers sitting in every seat and standing in the aisles. This way, Metro officials can drive the hybrid 12 to 18 hours a day to test its hardiness and ability to handle on-the-road challenges such as the Queen Anne Counterbalance and the Renton S-curves.

The hybrid articulated bus is the only one of its kind in the world. It was made for Metro by New Flyer Industries, with a hybrid electric drive supplied by Allison Transmission, a division of General Motors.

The bus works much like current small hybrid gas-electric cars. In the bus, electricity is generated by a computer-managed diesel engine. That electricity is stored for future use, and can reduce fuel consumption by 20 to 40 percent.

The new bus could significantly increase transit productivity, while protecting the environment by decreasing harmful emissions.

If all goes well with the road testing, Metro could order up to 200 hybrids next spring to replace the aging Breda buses that now travel cross county and through the downtown transit tunnel. King County is currently looking at ways to make the tunnel work for both buses and Sound Transit’s light rail project. Metro officials say it appears this hybrid could work very well in the tunnel alongside light rail trains.

During the upcoming road testing, the hybrid will be given a unique route, designed to put the hybrid through a variety of situations and accumulate data on how it handles the wear and tear of daily driving.