King County Metro Transit has signed a contract to take delivery on 213 new hybrid diesel-electric buses. The order also includes another 22 hybrid buses for Sound Transit.

The two transit agencies are looking to replace more than 200 dual-mode buses that now operate in the downtown Seattle bus tunnel, as well as the surface streets throughout King County. The agency’s current fleet of Breda tunnel buses is aging, and a new bus was needed that could operate in the tunnel alongside a future light rail line.

"We needed a large bus that was clean, efficient, and met some unique operating needs," said King County Executive Ron Sims, who also chairs the Sound Transit Board. "We are currently designing ways to make our downtown transit tunnel work for both buses and light rail. We needed a bus that could take us in a new direction."

Metro has been testing the new technology extensively over the past year. The agency bought one demo hybrid bus last fall and proceeded to put it through intensive stress testing and then placed it on regular routes with passengers.

"The new hybrid was able to go anywhere in Metro's system with ease," said Metro General Manager Rick Walsh. "There are no limitations to its application, because it is fuel efficient and not dependent on overhead wires."

The order for the new 60-foot articulated buses was placed last week with the New Flyer Corporation. New Flyer will manufacture the buses to Metro’s and Sound Transit’s specifications, using a General Motors Allison electric drive system and a Caterpillar engine. Each bus costs $645,000.  The purchase will give Metro the largest fleet of hybrid buses in the world.

The big bus works much like the small hybrid cars that are becoming so popular with consumers these days. 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 hybrid bus is also extremely clean when it does burn diesel. Like every other Metro bus, this vehicle will use Ultra Low Sulfur Diesel fuel. Carbon monoxide and hydrocarbons are reduced by as much as 99 percent over the Breda’s emissions. There is no diesel exhaust odor, fuel efficiency is increased, and on-road performance is improved.