Washington, July 29 : A Michigan-based company carrying on its business operations as Fisher Coachworks has officially launched a lightweight urban transit bus, which has double the fuel efficiency of conventional hybrid buses.
The 40-foot green technology bus also has insights from Oak Ridge National Laboratory, and funding from the Department of Energy for its commercialisation.
The bus features a high-strength stainless steel body and chassis and a hybrid power system that drives it primarily with stored electrical energy.
This approach reverses the paradigm of conventional parallel hybrid designs that use electric energy only to supplement the acceleration and torque requirements of a diesel engine.
Experts behind this bus have revealed that it has a chassis made of Nitronic 30, a nitrogen-strengthened stainless steel that is stronger and stiffer than conventional steel.
According to them, these attributes translate into less material required for a chassis, resulting in reduced weight.
"Nitronic stainless steel is incredibly durable and enables our chassis designs to have significantly longer service life vs. ordinary steel vehicles. The fact that stainless is also 100 percent recyclable and more environmentally friendly to produce than aluminium makes this an ideal green raw material for vehicle structures," said Bruce Emmons, president of Autokinetics of Rochester, Michigan, which developed the bus
Emmons says that another advantage of Nitronic 30 is that it makes for excellent mechanical properties at sub-zero and elevated temperatures, along with low-temperature impact resistance and superb resistance to high-temperature oxidation.
He agrees that this material is more costly than conventional steel, but insists that the additional cost is offset by design innovation, parts consolidation, and streamlined manufacturing processes.
"The benefits of improved strength-to-weight performance quickly compound to all other vehicles systems such as smaller tires, lighter brakes, batteries, motors and so on. By optimizing the total vehicle we have been able to cut the weight almost in half, which has led to performance improvements, most notably fuel economy gains," Emmons said.
Deliveries of the bus, which made its debut on Monday, are expected to begin in 2009.
Gregory Fisher, chief executive officer of Fisher Coachworks that licensed the technology, says that besides its reduced weight and hybrid power system, the bus will also incorporate a number of advanced design features and advantages.
He says that improved vehicle safety for passengers, lower cost, reduced noise, and improved ride dynamics are some of the advantages.
The major advantage, though, will be in cost to operate, according to Fisher.
Emmons hails ORNL for its contributions to the creation of this bus.
"ORNL was the first to suggest the possibility of applying Autokinetics' light-weighting ideas and technologies to the bus field. Without that insight, this program would never have happened," Emmons said.
Phil Sklad of ORNL's Materials Science and Technology Division, who served as the program manager and technical monitor, said: "This is a perfect example of how the Department of Energy, a national laboratory and the private sector can collaborate to produce something that is potentially of great value to society."
Fisher Coachworks, located in Troy, is planning to use this patented technology for transit buses, and other commercial vehicle market segments that would benefit from vastly improved fuel economy in urban stop and start applications.