I met with Mark Roush recently at the Technology & Maintenance Council (TMC) annual meeting a week back to talk about advances in trailer engineering. He‘s a favorite contact of mine - an engineer always thinking outside the box, aiming for new and different ways to build the products the trucking industry relies on day in and day out to deliver freight for customers.
Three years ago, Roush - director of engineering for Vanguard National Trailer Corp., Monon, IN - and I sat down to talk about future concepts for trailers: how could they be built differently to reduce weight, improve longevity, reduce use of wood, etc. One of the more innovative things turning over in his mind back then revolved around gluing trailers together with “super adhesives.”
Today, that concept is a reality - he showed off two 28-foot “pup” trailers to me at TMC with sidewalls literally glued together, with rivets only used along the top and bottom. It took three guys just 15 or so minutes to put a sidewall together using adhesives, he told me - something that took three times the amount of workers to achieve in the same time frame using rivets.
(To watch a video report on Vanguard's 'glue trailer,' just click on the link below)
Roush reminded me, though, that this is only the start of the process: after TMC, those two trailers are set to undergo some serious durability test track trails to see if they‘ll hold up under real-world stresses. In the meantime, he‘s got a 53-foot trailer model with glued-together sidewalls being prepped for the Mid America Trucking Show.
“Glue doesn‘t rust and it holds just as well on brackets as rivets do -- even better in some cases,” he told me. “What people don't realize is that the glue we‘re talking about has a sheer strength of 2,000 psi [pounds per square inch], whereas your average rivet has a maximum sheer strength of 1,200 psi. So you‘re using something that theoretically has a much stronger bonding force between the sidewalls of a trailer and its structure, not less.”
(Vanguard's 28-foot pup glue trailer on display at TMC)
And again, by using glue, trailers can be manufactured faster and cheaper, without compromising strength and durability. “One of the most costly parts of manufacturing a trailer is the man-hours it takes to rivet the sidewall to the frame, and every rivet represents a metal-on-metal contact point where rust and corrosion can develop over time,” Roush says. “With glue, you‘re using one single sheet of aluminum sidewall without rivets. You‘re taking a tremendous amount of hours out of the production process, yet giving the trailer more durability in terms of corrosion prevention.”
Reducing the number of weld points on a trailer is another benefit to using adhesives, he explained to me. “Welds create a weak point where corrosion can gain a foothold,” Roush said, “We pre-assemble as many components as possible and try to maximize corrosion protection by taking the pieces of the trailer with the most weld points and galvanizing the entire section. But if you can go to adhesives, you totally eliminate that problem.”
Roush is no stranger to this kind of innovation, as over his engineering career he‘s designed and tweaked a wide variety of trailer models, from flatbeds at Dorsey Trailer to refrigerated and insulated units for Kidron.
Finding ways to make trailers less expensive yet more durable has been a challenge wherever he‘s worked. And Vanguard is no exception, where the focus is now on finding ways to better protect cargo and minimize corrosion while reducing weight and maintaining durability.
That‘s not all he‘s cooking up in his research lab, either. Right now he‘s working on a trailer floor made with a “pultruded” composite material - lightweight yet durable resins “pulled” into specific shapes with specialized machines before they harden. The benefit here is that Roush could slice 700 pounds out of a standard 53-foot dry van using a composite floor, while also improving traction and longevity.
The perennial problem with wooden floors is that over time, they get wet and start to rot. While Oak is the best in terms of resistance to rot, it‘s also one of the most expensive woods on the market. Roush is already addressing that by using metal flooring at the trailer door end, with less-costly Maple wood flooring for the rest of the interior.
He‘s even starting to visualize making an entire trailer via pultruded-style materials, with sidewalls, floors, and doors built separately and then combined mainly with adhesives, with bolts and rivets at major connection points. That would really save on trailer unit weight, he believes.
But Roush also cautions that there is a limit to how far you go in reducing trailer weight. “When you are trying to save weight, you usually have to give up something -- either take something out of the structure, which can compromise the integrity of the unit, or change the design,” he explains.
Still, it‘s great to see all these innovative ideas being applied to what truckers have long considered just plain old boxes on wheels. Whether they work out or not in the long run, one thing is for certain - it‘s a sign that trailer engineering isn‘t playing second fiddle anymore to anything in trucking these days.
