Dickinson ISD operates 28 propane-powered school buses and plans to add more to its fleet in the future.
Dickinson Independent School District
Growing green, fleet to facility
When Dickinson Independent School District’s (ISD) transportation staff moved into their new facility last August, they began one of their newest green initiatives: operating propane-powered school buses.
Fleet Manager Ken Winters says 25 of the district’s 28 2012 Blue Bird propane buses were funded by Department of Energy and Texas Commission on Environmental Quality grants, and a refueling station was also secured through grant funding.
“We’re going to keep adding to the fleet as the budget allows. Our goal is to have more than half of the fleet on propane,” Winters says.
Propane use extends to the white fleet as well. Two trucks have been converted to run on the fuel, and vans will soon be converted.
The operation’s 57 2005 and newer diesel-powered school buses are equipped with crankcase filters, and they are electronic fuel injected and feature EGR technology.
Beyond the fleet, the new facility is on an energy management program. T5 high-bay lights, which Winters says are bright but have low amperage use, are used in the facility and the maintenance garage. Moreover, some of the parking lot lights operate on 50-percent power in the middle of the night, and the rest turn off.
“We have a strict policy on not leaving any lights on in offices if you know you’re going to be out for more than five minutes, and all computers and monitors have to be turned off overnight,” Winters adds.
The employees further reduce their carbon footprint by recycling glass, paper and plastic in an EcoRewards dumpster on-site.
On the maintenance end, waste oil and antifreeze are recycled, and used tires are recapped. Tires that aren’t recapped are sold back to the manufacturer. Winters says they receive about $65 per casing, which goes toward the purchase of new tires.
Increased fuel economy and emissions reduction are also important to the team.
Tire air equalizers with sight indicators have been installed on the buses’ rear dual tires to help maintain proper tire pressure. Winters says this reduces the chances of running a tire low on air, which would damage it and affect fuel economy. He says the fuel savings from proper tire pressure is approximately 10 percent.
If the technicians notice poor fuel economy in a bus and have ruled out a mechanical problem but notice that it has extensive brake wear, they share with drivers ways to not only improve buses’ fuel economy, but also to help increase the vehicles’ life through their driving habits.
When the transportation department’s new facility was built last year, a propane refueling station was installed on site, and steps were taken to preserve the trees around the building.
The techs recommend such practices as easing up on the throttle when approaching a stop, refraining from hard acceleration, and not hitting potholes and running over curbs.
“We’ve seen that driving habits are very crucial on propane buses,” Winters says. “If you have a lead foot on a propane bus, it can really make a difference in fuel economy.”
To reduce exhaust emissions, drivers are only permitted to idle their buses for up to three minutes.
Routes have become more efficient through the use of GPS and routing software. Winters says this has helped Dickinson ISD to reduce mileage, and there is an added safety benefit: The software helps create routes that require a minimal number of left-hand turns across traffic for school bus drivers.
“We don’t let our students cross any major roads,” he adds of creating routes. “We feel it’s much safer if students can exit on the curb.”
— KELLY ROHER
School buses: 85
Alternative fuels used: Propane
Students transported daily: 5,000
Schools served: 13
Transportation staff: 120
Area of service: 68 sq. miles