Training the Wind

A tight tarping job can save you time and money

Successful tarping is a twist of art and a tug of science. No two loads are tarped the same. “Every load is different, and every load has to be secured differently,” says Rosco Wood, driver for Denis Gray Trucking in Sumner, Wash.

Adds Fred Jones, an owner-operator leased to Davis Transport of Missoula, Mont., who figures he’s spread tarps for 25 years, “There’s a lot of thinking to running a flatbed and tarping.”
You’ll know quickly if you’ve done a good job tarping your load. If your tarp is billowing or flapping at highway speeds, it’s time to pull over and start over. A lackadaisical tarping job costs you time and money.

“The best thing to save money and reduce drag is to get the tarp on and keep it tight,” Jones says. “It’s well worth the time spent at the start.” Understanding wind flow will help in tarping your load. When winds blow over the top and flow behind your cab, they have to go somewhere; they flow off to the sides where they create a vacuum, Jones says. If your tarps aren’t tied tight, the wind will catch the edges. “I’ve heard of troopers giving tickets for the obstruction,” he says.

“Tarping loads isn’t an exact science,” says Robert Twiss, driver for Nashville-based Western Express. Even so, when positioning tarps, ensure you’re placing the flaps and corners properly to reduce drag. On the front of the trailer, the end flap overlaps the corners, while on the back of the trailer, the corners overlap the flap. “Any open edge is going to catch air,” Twiss says. “You want to keep the sides as flat as possible. And you want to start your bungees from the rings closest to the trailer head.”

Start at the back of the trailer with a tarp and secure that tarp first, Wood says. Take another tarp from the trailer front and overlap the first tarp. “Start at the back because you want the one on the front to overlap the other for less wind resistance,” he says.

Taper your tarps to the shape of the load you’re transporting, Twiss says. Streamline the shape and elongate it as much as possible. “You want to make it narrower going into the wind,” he says. If you’re tarping a load with uneven heights, start with the highest part.

If your load is higher in the middle, begin tarping in the middle.

If part of your load is higher than the rest, the best location to place it to reduce wind resistance is behind the cab. If that part of the load is heavier, however, you have to be concerned about weight and spreading the weight over all the axles, Jones says. When loading, request that heights be evened out where possible. “Many forklift operators will try to make it level in height,” Jones says. “I’ve never had a customer argue with me and say, ‘This is the way we load it, and that’s it.'”

On a tall load, make sure your tarp is touching the trailer deck and tuck in the edges. Depending on the size of the load, you can use one or two tarps. “If it’s going to get wet, it’s going to get air,” Twiss says. “Any open pocket that collects water is going to collect air. You want to streamline it where possible to eliminate the pockets.”

If you have large deck gaps between items, you may need to improvise. Jones says one solution is to make “v-boards” out of two-by-fours and duct tape or a strap to create a shape that can be tarped. “I had a load where there was about a 10-foot gap between the pieces,” he says. “I took two v-boards, overlapped them about a foot and duct taped them. When I put those two boards together, it bridged the gap, and the tarp had something to lay on.”

Secure your load tightly, but not so tight your tarps are going to rip on corners or edges. If a tarp is too tight, the wind will tear it, Twiss says. “You not only lose revenue on the fuel, but you lose revenue on the tarps,” he says.

While bungees are popular, Jones uses rope instead. He says rubber bungees will stretch or even break if the wind catches them, but once rope is placed tightly, it will stay tight without stretching. “Some people don’t want to take the time to use rope,” he says. “You can leave the rope in the tarp when you roll the tarp up. Rubber bungees you have to take off and restring them in every hook, every time.”

Cover for a sensitive load
Rosco Wood’s load of a magnetic resonance imaging machine put his tarping skills to the test. The Denis Gray Trucking driver was transporting the $2 million machine and other equipment from Seattle to a hospital in central Washington State. He had made three stops to pick up the device. The trip involved passing through the windy Cascade Mountains.

The magnet was tarped inside a metal cage, and Wood had placed two more tarps of his own over the cage and secured them with bungees. Before he headed through the mountain pass, he strung three straps over that part of the load for extra holding power. “Because I don’t have the load in a single piece [with different heights], the wind is going to catch this and pull my trailer all over the place,” he said before hitting the road. “It’s going to take my tarp and pull it to the side. I have to keep it absolutely dry under there.”

While you’re sitting waiting to get loaded, watch the veteran drivers and how they tarp their loads. They know the tricks of the trade and often are willing to help, says Fred Jones of Davis Transport. “Nine times out of 10, if you ask someone for help, they’ll actually come over and help you,” he says.