NOVEMBER/DECEMBER 2007
Scrap processors have a multitude of options for the trailers in which they transport scrap and the tarps they use to cover them en route.
BY JIM FOWLER
Moving scrap from Point A to Point B is an essential part of the scrap processing business. Though scrap can travel by ship, barge, and railcar, at some point scrap enters or leaves just about any facility in a trailer. Whether it’s an end-dump, gondola, roll-off, or hooklift, manufacturers agree that scrap processors are looking for two things in their trailers: light weight for maximum payload and durability for greater longevity.
To legally hit the road, trailers often need to travel under cover—not under an alias, but under a tarp. Processors searching for the latest options in trailer and tarping technology should read on.
Good for the Long Haul
Scrap processors turn to end-dump and gondola trailers to move scrap over long hauls, the difference between the two being how they discharge their scrap. In recent years manufacturers have made trailers stronger and lighter by using new materials. Though some scrapyards use aluminum trailers, high-strength steels, particularly the Swedish-made Hardox 450, have become more prevalent. The use of new materials is the most significant innovation in end-dump trailers, one manufacturer says. “High-grade, abrasion-resistant steel is used to produce large-cube trailers with capacities approaching 100 cubic yards, compared with 50 to 60 cubic yards in years past. A bigger cube with lighter-weight trailers means a more profitable payload.”
One vendor expects further innovation in trailer materials. “They build aircraft from composites, so why not scrap trailers?” he says. “It’s just a matter of dollars and cents. Everyone wants durability, longevity, and light weight. You pick up extra tonnage with lighter containers, and it doesn’t take that many trips for the trailer to pay for itself. I see composites coming in probably two to three years.”
Processors are becoming more sophisticated in selecting the right trailer for the job, vendors say. “In days past, they would put whatever they had in the trailer, beat it up, and then buy a new one,” a manufacturer says. “That’s not the case anymore. Processors are matching grades and types of scrap they are hauling with the trailer that best accommodates that material.”
Trailer design innovations aim for greater payloads or lower fuel costs. One manufacturer has engineered the back doors to open into the trailer when it’s empty to allow air to flow through it, reducing drag and improving fuel efficiency. Another company is building trailers with rounded bottoms and straight sides. With this design, the manufacturer says, “by virtue of its shape, the number of side braces can be reduced. Eliminating side braces decreases the weight of the trailer and increases the cube. It also decreases wind drag and increases fuel efficiency.”
Another trend cited by one manufacturer is the smooth-side, or smooth-wall, tub and rear dump trailers that reportedly keep wind resistance and maintenance down. This vendor has developed extruded aluminum double-side panels that are stacked and welded horizontally. “We believe this design strengthens the side walls, especially when the trailer is being loaded or on the road,” the vendor says.
End-dump trailers are either framed or frameless. Frameless trailers are lighter, but some question their stability when dumping. “The issue of stability is still going on, but it’s not nearly as important as it was 10 years ago,” says one maker of frameless trailers. “Today the frameless trailer is recognized as a stable trailer.” A vendor of framed trailers disagrees. “Those who build frameless trailers maintain stability is not an issue, but it is,” he says. Frameless trailer designs vary, so potential buyers will want to carefully investigate the differences and their impact on stability.
Gondola trailers have come a long way from their early days, when scrap processors would buy a used flatbed trailer and weld sides and a back door on it. But refurbishing old flatbeds can be a risky business, one manufacturer says. There’s really no way to know the trailer’s condition, particularly the axles. “With our construction techniques, we’ve reduced the trailer’s weight and provided the customer with a totally new unit. The difference between a homemade gondola from a flatbed and a new gondola is often measured in the dramatic reduction in pull-over rates experienced by operators,” she adds.
Gondolas are not a good choice for carrying loads that must be dumped at the end of the line. If a magnet, grapple, tipper, or other lifting device can remove the load at your final destination, however, a gondola might be a good choice. “The gondola is lighter because it doesn’t require the hydraulics needed to dump the trailer, so it provides a bigger payload and costs less,” a gondola vendor explains. Her company’s trailers hold up to 113 cubic feet of material.
Carrying Removable Containers
For spotting containers at customer locations or other yards, roll-off and hooklift trailers are the two main options. In addition to weight and durability, prospective buyers should consider maneuverability, lifting ease, driver convenience, and cost.
For those interested in carrying more trailers with fewer tractors, double-hauling trailers that use “B-train” attachments, long used in Canada and Mexico, have just come to the United States. The B-train connector “eliminates the whip of the converter dolly on an A-train system,” one manufacturer explains. In this design, “a standard tractor picks up a container on a trailer no longer than 281/2 feet. A sliding suspension from the back of the front trailer reveals a fifth wheel to which a second trailer is fixed.”
This vendor believes B-train trailers will draw scrap processors’ interest, especially in states such as Texas and Oklahoma, where processors have long hauls of unprepared scrap from customers and feeder yards. “The B-train allows you to haul two roll-off containers, which means you can call on two accounts and drop two boxes using only one tractor,” he says. “The result is greater efficiency and reduced costs.” Further, he says, “in addition to running the trailers as doubles, you can break them apart and run them as singles.” In a similar vein, one vendor plans to introduce a new, lighter, two-box roll-off trailer.
Another manufacturer sees growth in the short end of the trailer market. He has introduced a roll-off trailer that’s just 26 feet long. “With a tandem-axle tractor, the unit is nearly as short as a roll-off truck, but it hauls more legally,” he says. “If a processor is not making full use of his tractors, he can use this trailer for $40,000 rather than buying a new roll-off truck for $150,000.”
Scrap featured hooklift hoists in the July/August 2006 issue, but at least one manufacturer has made a notable change in its hooklift design since then: It switched from a rectangular sliding jib to a hexagonal one. “We did this to add structural integrity and strength to the booms—to keep them from flexing from side to side—to make the jib more durable, and to ease the replacement of wear pads, which now takes only 20 minutes,” the vendor says. “With the other versions available, it is probably an 8- to 10-hour job.”
One more note on trailers: Companies operating in Canada should be aware that Ontario has reportedly changed its regulations dealing with the location of lift axles on trailers. Under the new regulations, lift axles have to be steerable. “Trailers in service today are grandfathered from these changes,” one manufacturer notes.
Put a Lid on It
Once a yard has purchased a trailer, the next consideration is how to cover it. Manufacturers have created a wide array of tarping systems, some of which are specific to certain types of trailers. “Driver-friendly” is what most vendors aim for in tarp system design. After all, a vendor notes, “the driver decides how he’s going to operate the tarp system and how he’s going to take care of it.”
Manufacturers suggest that processors looking at tarping systems develop a checklist of their specifications to find the product that best fits their needs. They should make note of
• the size of the container(s) and/or trailers they’re covering,
• the type of scrap they’re hauling,
• how they will load scrap into the container, and
• how many times a week they will use the unit.
Tarps with arm systems are the most common in the scrap industry. In the simplest terms, arms mounted on the side of the trailer pull the tarp, which is fastened to an axle roll behind the tractor. The axle roll is either attached to the gantry mounted on the truck or attached to the arms. Arm systems vary from manufacturer to manufacturer in arm material, design, and power source.
Companies typically make tarp system arms from aluminum extrusions, aluminum extrusion composites, or steel. Each material has different benefits and drawbacks in terms of weight, strength, durability, and repair and replacement cost.
The power source might be hydraulics or electrically powered springs. One tarp-system maker says hydraulic systems are 95 percent of what he sells for roll-off trucks. “You tie into the truck’s hydraulics either by building in extra valve banks with the hoist or by using our cover control valve to run it,” he explains. “The advantage of running it into the truck’s valve banks is that you eliminate an extra control valve. By having only one source, you can control what goes in and what goes out of each valve, so there is less chance of contaminating the hydraulic oil.” The hydraulics power a rack-and-pinion system that rotates the arms and controls their speed moving forward and backward.
One vendor cautions against the use of hydraulics in smaller operations that don’t have skilled mechanics capable of working on them, however. “If you don’t have trained people, you probably want to use an electric system rather than tapping into the truck’s hydraulic system.”
One alternative to a hydraulically powered system is an electric motor with spring technology. One vendor describes his electric tarping system like this: “There is a series of six individual springs on each side of our pivot box—up to 12 springs for longer container trailers. When you lift the tarp out of the spool, the springs are pulling the tarp back and the brake on the motor is controlling the speed of the tarp’s flow. To untarp the load, the motor reverses and cranks the tarp back onto the tarp spool while pulling the tension back on the springs.”
Tarp arm systems can come with fixed- or adjustable-length arms. A processor that always hauls containers of the same length can go with a fixed-arm system, which is less expensive and, one vendor says, stronger than an adjustable arm. Adjustable-length arms are a necessity for yards that own a variety of container sizes, however. Methods of adjusting the arm length vary. One manufacturer mounts cylinders horizontally along the truck frame. “The slider moves the pivot forward and backward, so by adjusting it you adjust the position of the arm and can tarp a variety of different-size containers,” he says. Another manufacturer uses a fixed pivot with telescopic arms that move in and out to accommodate different sizes of containers.
The latest automatic tarping trend is systems that keep the driver off the load and out of the truck cab when operating the tarp. “We don’t want the truck moving while the driver is operating the tarping system,” one vendor says. “There is too much risk of the driver running into something. We also want drivers out of the truck so they can be aware of clearance issues around the trailer when they operate the system. We want them parked and stationary.” Some vendors offer lever controls mounted on the truck; others sell wireless remote-control systems that allow the driver to stand away from the truck and get a better view
of the tarp while it’s moving.
The tarp gantry, located behin d
the tractor, can be raised and lowered hydraulically by using either the truck’s hydraulic system or a separate hydraulic pack. Raising the gantry keeps the tarp from dragging across the scrap during the tarping and untarping process. Processors who are hauling minimal loads and cannot justify the cost of an automatic system can look for semiautomatic gantries that allow drivers to pull the tarp out manually. But vendors say safety and efficiency concerns are making automatic systems more prevalent.
One manufacturer claims a flip-style tarp is the most efficient for end-dump trailers. His system mounts springs in the middle of the trailer at the bottom. Arms on the side lift the tarp up and over the load either electrically or manually. (Most of his customers choose the electric option, he says.)
Another manufacturer has developed a “dual-lid” tarping system for gondola trailers. “Just picture a trailer 8 feet wide and 40 feet long with a rotary actuator on the front of each corner,” he says. “There’s a panel 4 feet wide and 40 feet long on each side” that’s made of a hard plastic mesh. To uncover the trailer, “the panel is going to flip up, rotate, and hang right along the sides of the trailer—it does a 270-degree rotation on both sides.” This system costs less and is easier to maintain compared with side-roll tarps, he says. “Side-roll systems are expensive to maintain. The replacement cost for the tarp is $350 to $400, and it takes two people a couple of hours to replace it. One person can change a dual-lid flip tarp in 15 to 20 minutes. It’s definitely a maintenance issue.”
A low-cost alternative to all of these tarping systems is disposable, light polypropylene netting. Designed for one-time use, the material can cover a 36-foot gondola trailer for about $10, the vendor says. “It is easily cut to size with a utility knife” and secured to the trailer with cable ties, he says. A processor who has been using the material for two years says that even though the driver must climb on the trailer to spread the netting over the load, the company has not experienced accidents because of that.
And one manufacturer is truly thinking out of the box—or in this case, off the truck. It sells a manual tarping system for roll-off and lugger boxes sitting in a yard. The unit can be mounted to the box or, with the addition of legs, be portable and easily moved with a forklift. Auto recyclers, industrial scrap generators, and scrap processors are using the stationary system with a solid, vinyl tarp to keep material such as oily engines, motor blocks, or turnings dry. Uncov-ered containers tilt as they are loaded onto trucks or trailers, the vendor explains, and water that has collected inside can spill and contaminate the ground. Covered containers avoid that problem.
Which tarping solution is the best? Vendors of automatic systems say to consider the potential cost of workers’ comp claims if a driver is hurt manually tarping a load and the cost to replace ripped tarps damaged during manual tarping. Vendors of manual systems say to consider the weight of the tarping system and the impact of that weight on your payload. Other ownership cost considerations include durability, longevity, maintenance and repair costs, warranties and guarantees, and the potential expense of fines for loads not tarped if the system does not work or the driver doesn’t use it.
Whether automatic, manual, or one-time-use, a tarp of some kind is essential. “Federal law requires that any roll-off container that has something protruding above the top edge must be tarped,” one manufacturer cautions. “Some states have become very stringent, to the point that if you have a container on the road, you’d better have it tarped.”
Jim Fowler is retired publisher and editorial director of Scrap .
Scrap processors have a multitude of options for the trailers in which they transport scrap and the tarps they use to cover them en route.