Steel skins form trailer skirts that cut drag, boost fuel efficiency
June 2014 - Con-way Freight, a subsidiary of Con-way Inc., recently partnered with Wabash Composites, a division of Wabash National Corporation, to outfit its line-haul trailers with the DuraPlate Aeroskirt, a trailer skirt designed to reduce wind drag, carbon emissions and ultimately improve fuel economy.
After testing various models, Con-way Freight chose Wabash Composites’, DuraPlate Aeroskirt, based on its design, one of many initiatives that Con-way implemented to improve gas mileage and reduce its carbon footprint.
Con-way Freight is an EPA Smartway-approved carrier expanding its environmentally conscious efforts by adopting such technologies as the DuraPlate Aeroskirt. Wabash Composites introduced the DuraPlate Aeroskirt in 2009 after recognizing customer need for improved fuel economy. Con-way Freight believed this product was the best fit for its line-haul equipment because it best met the company's needs for effcient installation, consistency, durability and minimal maintenance.
The DuraPlate Aeroskirts use a four-panel design consisting of two external steel skins fused to a high-density polyethylene core, equipped with a proprietary spring bracket system that allows the skirt dexterity alongside over-the-road endurance, reducing damage to the undercarriage that road debris will often cause. These heavy-duty panels are manufactured using recycled domestic steel at Wabash National’s facilities in Lafayette, Indiana, which are then fitted to Con-way’s 28-foot line-haul trailers. Each steel panel weighs 48 pounds, with an additional 45 pounds of installation hardware, making it 93 pounds of additional weight to the trailer. When asked about the additional weight and its effect on fuel consumption, Con-way Freight senior director of maintenance Tim Killilee said his company conducted extensive road tests—placing trailers with the DuraPlate Aeroskirt side by side with trailers not fitted with the same equipment.
“We ran these units during our pilot tests that had these trailer skirts in the same lanes as trailers that didn’t, so you had like configuration of units running the same miles and the same lanes, i.e., Minneapolis, Minnesota to Des Moines, Iowa, so we could run those side by side and [each truck] would [face] the same contributing factors.”
So although the skirt added to the trailers’ gross weight, the equipment significantly reduced wind drag, diverting air away from the trailer, streamlining it and ultimately reducing resistance and improving fuel economy.
DuraPlate Aeroskirts have achieved fuel savings of up to 6 percent with annual fuel savings from 900 to 1,000 gallons, Wabash Composites sales director Brian Fanelli disclosed. With U.S. diesel prices at the pump averaging $3.67 the last week of May, that’s a projected savings of $3,303 to $3,670 per year, per outfitted trailer.
In addition to the environmental benefits of the DuraPlate Aeroskirt, it helps provide the driver with greater safety and a smoother ride. Over-the-road tests showed improved trailer stability by eliminating cross winds that create a “lifting” effect which, at high speeds, can make the trailer sway. Additional advantages to the Wabash Composite design include its lower maintenance and cost of ownership if any damages were to occur, the manufacturer claims
Con-way Freight has not fully deployed every trailer skirt it bought yet; about 50 percent of its line-haul trailers are fitted to date. Con-way Freight reports no significant damage to any trailers thus far and, in terms of stability and safety, it has received positive feedback from drivers.
Con-way plans to outfit about 16,000 trailers and complete installation by August 2014.