Revolutionary green technology bus

Jul 28, 2008
Fisher Coachworks' lightweight hybrid bus, which achieves twice the fuel economy of current hybrid buses, has some Oak Ridge National Laboratory roots. Credit: Fisher Coachworks

Insight from Oak Ridge National Laboratory, commitment from two Michigan companies and funding from the Department of Energy have led to the commercialization of a lightweight urban transit bus with double the fuel efficiency of conventional hybrid buses.

This new green technology 40-foot bus features a high-strength stainless steel body and chassis and a hybrid power system that drives the bus 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.

At the heart of the bus is a chassis made of Nitronic 30, a nitrogen-strengthened stainless steel that is stronger and stiffer than conventional steel. 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," said Bruce Emmons, president of Autokinetics (www.autokinetics.com/) of Rochester, Mich., which developed the bus. "The fact that stainless is also 100 percent recyclable and more environmentally friendly to produce than aluminum makes this an ideal green raw material for vehicle structures."

Additional advantages of Nitronic 30 include excellent mechanical properties at sub-zero and elevated temperatures along with low-temperature impact resistance and superb resistance to high-temperature oxidation. While this material is more costly than conventional steel, Emmons noted 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," Emmons said. "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."

In addition to its reduced weight and hybrid power system, the bus will incorporate a number of advanced design features and advantages, said Gregory Fisher, chief executive officer of Fisher Coachworks (www.fishercoachworks.com/), which licensed the technology, has produced a prototype and plans full commercialization. The bus made its debut today and deliveries of the bus are expected to begin in 2009.

Some of the advantages are improved vehicle safety for passengers, lower cost, reduced noise and improved ride dynamics. The major advantage, though, will be in cost to operate, according to Fisher.

Specific contributions from ORNL included computer crash studies and infrared thermal imaging to evaluate the quality of some of the initial laser welds in the structure. Early tests showed some problems with the laser welding technique, so Autokinetics chose to use resistance spot welding in most places and tungsten inert gas welding for the remainder of the joining needs.

But even before its technical contributions, Emmons said ORNL had a huge impact.

"ORNL was the first to suggest the possibility of applying Autokinetics' light-weighting ideas and technologies to the bus field," Emmons said. "Without that insight, this program would never have happened."

Phil Sklad of ORNL's Materials Science and Technology Division served as the program manager and technical monitor and noted that DOE's $2.5 million investment in this project is being rewarded with a revolutionary bus.

"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," Sklad said.

Source: Oak Ridge National Laboratory

Explore further: Boeing 737 factory to move to clean energy

add to favorites email to friend print save as pdf

Related Stories

Climate change could leave cities more in the dark

3 minutes ago

Cities like Miami are all too familiar with hurricane-related power outages. But a Johns Hopkins University analysis finds climate change will give other major metro areas a lot to worry about in future storms.

Mathematicians prove the Umbral Moonshine Conjecture

4 minutes ago

Monstrous moonshine, a quirky pattern of the monster group in theoretical math, has a shadow - umbral moonshine. Mathematicians have now proved this insight, known as the Umbral Moonshine Conjecture, offering ...

How electrons split: New evidence of exotic behaviors

9 minutes ago

Electrons may be seen as small magnets that also carry a negative electrical charge. On a fundamental level, these two properties are indivisible. However, in certain materials where the electrons are constrained in a quasi ...

Recommended for you

Cook farm waste into energy

5 hours ago

It takes some cooking, but turning farm waste into biofuels is now possible and makes economic sense, according to preliminary research from the University of Guelph.

Developing a reliable wind 'super grid' for Europe

8 hours ago

EU researchers are involved in the development of a pan-European 'super grid' capable of dispersing wind power across Member States. This will bring more renewable energy into homes and businesses, help reduce ...

Boeing 737 factory to move to clean energy

Dec 16, 2014

Boeing said Tuesday it plans to buy renewable energy credits to replace fossil-fuel power at the factory in Washington state where it assembles its 737 commercial airplanes.

User comments : 2

Adjust slider to filter visible comments by rank

Display comments: newest first

thku4grace
4 / 5 (1) Jul 28, 2008
Sounds great! But I don't see any information on how much a greater range this bus can manage. I also don't see how much more this bus will cost. "More costly" could mean $2.5 million a bus if we aren't careful.
lengould100
not rated yet Aug 14, 2008
I suppose the new bus is a worthwhile demonstration of a new materials process, but "more recyclable than aluminum"? And perhaps some aircraft engineers could help if you're having trouble with aluminum at low temperatures.

Should put a shorter leash on the PR flaks, it damages credibility.

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.