Kirk Altrichter, vice-president of maintenance for Gordon Trucking Inc., can tell you more than few things about trailer skirts and how to choose the right ones. His search began about nine years ago, when they were barely heard of, and while he’s settled on Freight Wings, he continues evaluating various devices to stay abreast of what’s out there.

His main advice is to look beyond initial purchase price to a product’s serviceability, and its total costs over what should be a long lifetime. That requires the right materials and design.

“We started with aluminum and moved into thermoplastics,” Altrichter said by phone and e-mail from the fleet’s headquarters near Seattle.  “Aluminum did not hold up; the first installation didn’t even make it through one trip. Rivets started pulling through the aluminum,” which rigidly resisted wind and vibration.

Further into the search, flexible thermoplastics began being used and some seemed promising, so Altrichter began looking for fuel-economy results by doing three separate TMC-SAE Type IV tests over five years. The first was in 2004 and all involved Freight Wings on 53-foot vans. 

The Type IV tests were run on I-90, in Washington, between Bellevue and Spokane, he said. The tests indicated definite fuel savings, and regular service with Freight Wing-equipped trailers shows an improvement of 0.3 mpg.

Just as important, the skirts and their supporting structures flex to avoid damage. Materials and configurations have changed.

“We’re on the eighth or ninth iteration,” Altrichter said. “Mounts now are almost like carbon-fiber tent poles. They will bend 60 or 70 degrees. The skirts also give.”

In 2009-10, GTI installed 1,800 sets. All but three, which were damaged beyond repair in wrecks, are still in service.  Altrichter expects them to last 10 years or more.

Subsequent purchases have come in batches.

“Since 2009, GTI has made numerous purchases of Freight Wing products,” he said.  “Our typical purchase quantity is a trailer load of 250. We currently have 4,600 sets of Freight Wing trailer skirts,” which constitute 72% of the 6,400-trailer fleet.

“We do not have any other skirts running in quantity, although we have evaluated most of the competitions products and continue to evaluate,” he said.

In deciding what to use, price is just one consideration, Altrichter said. Look also at the ease of installation, which improves with experience, and whether you can buy without incurring the federal excise tax on new equipment.

Buying skirts separately and installing them after the trailers are in service for six months or so can get around the FET. Always get sound financial advice on FET matters.