School Bus Transportation News at STN Media

The Environment and New Bus Service Life

by Dale Goby
Executive Director, Office of Student Transportation for Detroit Public Schools

Environmentalists are forever advocating a cleaner environment and a reduction in the use of natural resources and school buses are frequently one of their targets. We all want clean air and a reduction of the pollution in our environment for a healthier quality of life. And there is much we can do to improve our performance in this area.

In the Midwest and Northeast areas of the U.S. , it is common for school buses to operate on only a six, eight or ten year bus service life. As school transportation professionals, we can help obtain environmental objectives by considering the purchase of an improved quality bus designed and manufactured to provide a minimum 15-year service life. Think of the steel that must be processed and milled from raw materials to produce a single bus body, frame rails, cross-members, wheels, suspension systems, steering systems, and seat frames. A new bus body also requires considerable amounts of new glass, upholstery material, seat foam, and paint materials. Think of the steel that must be processed from raw materials to produce an engine block, cylinder head, transmission case and gears, axle components, etc.

15-year Service Life

Thanks to work already done in the over-the-road truck and transit bus industry, technology currently exists for a school bus that will easily deliver an extended 15-year service life. In order to obtain federal funding for ALL new city transit buses, they must undergo durability testing to survive a minimum 12-year, 500,000 mile service life. This is proof that the goal of a 15-year life school bus is attainable.

Currently available through some school bus manufacturers are upgraded high-strength 110,000 PSI chassis frame rails along with body structural reinforcement options. These components will end frame rail stress and tear failures. There are engines on the market that will deliver a 300,000 to 350,000 mile service life.

There is also the 12-year proven Allison upgraded MD World series transmissions that can also deliver a comparable service life. Only the Allison upgraded MD series product also has the option of programming the electronics at the factory that allows upshifting at greatly reduced engine RPM. With upshifting occurring at approximately 1,900 RPM instead of 2,400 RPM, fuel economy is increased approximately 1.8 MPG, a technique approved and appreciated by both environmentalists and the taxpayers who pay the fuel bills. Greater fuel economy means less fuel consumption and a reduction in harmful air pollution. With an overall reduction in engine RPM, engine service life before an overhaul is required is also substantially increased.

There are several anti-freeze/coolant products available that requires a longer six-year change interval. Oil change intervals can easily be extended to twice annually with a considerable benefit to the environment in reducing the need for oil purchases and reduced oil and filter disposal. For many transportation departments, that is a reduction of four to six oil changes annually. For about $150 extra, we can purchase 23 percent larger (8? inch wide) rear air brakes that provide shorter, safer braking and up to a 50,000 mile lining life. This is in place of the normal 30,000 miles life. All of these options help the environment.

Powder Coating

In recent years, all bus manufacturers have invested heavily in powder coating facilities to help reduce common corrosion and rust-through metal perforation failures. Let's put these financial investments to work. Some of the manufacturers now offer optional stainless steel stepwells to end expensive and troublesome corrosion and rust-through metal perforation failures in the stepwell area. The added cost of powder coating and the more expensive stainless steel in body construction can easily be cost justified in most harsh operating environments. .

While we frequently think we are "saving dollars" in electing to purchase a less expensive new bus with a projected six to eight year service life, we may actually be making an imprudent decision that is also not environmentally friendly. By buying the less expensive bus, we are requiring far more resources to be utilized resulting in far more environmental contamination than if you chose to spend a few more dollars (20 percent or so) and purchase the option of a longer life bus. Even if a ten-year bus owning cycle is used, we are still purchasing three rounds of buses over thirty years as compared to only two purchases for the same period for a 15 year owning cycle.

By expanding the new bus purchase cycle by 50 to 150 percent, we would all, including the bus manufacturers, be doing our share to help clean the environment and prudently optimize the management of our natural resources. Purchasing an environmentally friendly, more durable, longer life school bus with increased operating efficiency would prove a wise decision that would please conservationists everywhere. It's time for all of us to contribute our part towards improving our industry and, at the same time, reduce environmental impact.