Overdrive Magazine | Trucking Business News & Owner Operator Info
Issue link: http://read.dmtmag.com/i/856429
56 | Overdrive | August 2017 T he only thing more eye-popping than the aesthetics of Navistar's CatalIST Super Truck project is its $7 million price tag, but that's only a small part of the $40 million spent on the joint project with the U.S. Department of Energy. DOE's goal for its Super Truck projects with truck makers is to boost freight efficiency, a combination of equipment weight reduction and improved fuel efficiency, by 50 percent. Navistar says its CatalIST obliterated that target with a 104 percent improvement. "Freight efficiency is lit- erally how much freight X miles per gallon at 65,000 pounds GVW," says Navistar's chief engineer of advanced vehicle technologies, Dean Oppermann. Shedding weight To reduce the rig's weight, Oppermann and his team shaved 2,000 pounds off the trailer, but added 1,500 pounds back through aerody- namic devices such as slotted skirts, a boat tail, gap treat- ment and 48-volt solar pan- els. Aluminum landing gear and lightweight axles helped shed pounds, as did the thin- ner DuraPlate walls on the Wabash trailer. Working with an LT tractor, the team pulled out 2,300 pounds. The skirts and hood are carbon-fiber, and the wedge-shape cab is a car- bon-fiber skin over a steel structure. The windows and windshield are polycarbonate, which is lighter and stronger than glass. Super-single tires and alu- minum tanks round out most of the 2,800 pounds deleted from CatalIST, improving freight efficiency 8 percent. Aerodynamic design Oppermann added a boat tail that extends well below the trailer's underride guard and acts as an extension of the skirts at the rear of the truck. A full-width reinforced car- bon-fiber bogie treatment acts like a boat's hull, separating the airflow coming into the trailer axles. CatalIST's segmented Wabash trailer skirts flare inward as they reach the end of the trailer. The reduced aerodynamic benefit result- ing from the slotted skirt, Oppermann says, is offset by the skirts being lighter and having other advantages, such as having segments that can be replaced individually when damaged. At full height, the skirts ride well above curb level, so they're not easily deformed. The trailer's aerodynamic improvements reduced drag by more than 30 percent. CatalIST shed its mirrors, which slashed aerodynamic drag and wind noise and improved side visibility. Mirrors were replaced with exterior cameras and interior pillar-mounted monitors. Oppermann says most driv- ers who've tested the truck say it takes them about 20 miles to fully adapt to using the monitors. I got the hang of it in less than that. The wraparound wind- shield design provides excel- lent visibility of traffic. The polycarbonate windshield also allowed designers to keep airflow attached to the truck longer as it comes over the A-pillar. During my drive around Chicagoland, when rain droplets hit the wind- shield, they barely moved. The ones that did were forced left or right by air crossing the windshield rather than straight up. A side effect of keeping the air close to the truck around the A-pillar is additional noise reduction. With the truck at freeway speed, there was no noticeable change in tone when I rolled down the window. I didn't have to raise my voice to account for wind The performance of International's CatalIST more than doubled the goal of boosting freight efficiency by 50 percent. GREAT GAINS Savings on weight and aerodynamics give International's Super Truck high yields on efficiency BY JASON CANNON Photos by Jason Cannon DRIVE TEST