Equipment Focus: Truck Trailers

November/December 2015

Transporting scrap puts unique demands on trailer systems. Consider where you move your material, how much of it you can transport at a time, and what regulations may affect your choices when making your purchasing decision.

By Kenneth A. Hooker

Scrap recyclers have to do a lot of hauling. Whether you transport scrap from manufacturing plants and other sources back to your yard for processing or carry processed scrap to other facilities for further processing or consumption, or both, vehicles and containers tailored to the purpose and material at hand can accomplish the task efficiently.

One option for scrap companies is to buy specialized straight trucks that combine tractor and container in a single unit. If an operation is large enough to support and regularly use a large fleet of vehicles, that can be an attractive option, though it has some drawbacks. Trucks are expensive, and every hour you’re not using a specialized truck represents additional costs. Furthermore, if your dump truck engine needs repairs, the entire unit is out of commission until the work is done. For these and other reasons, many scrapyards choose to meet their varied hauling needs by acquiring specialized trailers.

Scrapyard managers say they select trailers that have adequate capacity for the loads they need to carry, that workers can load and unload safely and efficiently, and that are sturdy and durable enough to provide reliable service over the long term. The director of operations at one Midwestern scrap company distinguishes between trailers that receive materials for processing (such as luggers, gondolas, and roll-offs) and those that more often are for shipping material after it’s processed (such as vans, walking floors, and dumps).

Inbound Trailers
When customers or sales reps call and request that the company drop off a roll-off box at their site, the vehicle used depends on the site needs, according to the Midwestern operations director. This company operates both roll-off trucks and trailers. “We use straight trucks for accounts that have tighter access, where we can’t get the tractor and trailer in,” he says. “We’d prefer to always use a truck and trailer. It’s a question of downtime—if your truck is [on site], the whole unit is out of commission and you can’t pick up a container [elsewhere]. As a spare, it’s a lot less expensive to have an extra tractor than another whole truck. At some sites, we might use a lugger. Those are smaller containers, running from just a few yards up to 22 [cubic] yards,” whereas roll-off boxes range in size from 10 to 90 cubic yards. “Ours run from about 30 [cubic] yards up to 90,” he says.

An operations manager from a company that both hauls scrap metal and produces trailers cites another factor in the choice between straight trucks and trailers: “There was a big push, for a time, where companies were replacing their straight truck roll-off chassis with short roll-off trailers,” he says. Now, though, he sees “many companies holding on to their straight trucks due to driver shortages.” An advantage of straight trucks, he points out, is that they require only Class B commercial driver’s licenses. “With combination units, you get the flexibility to be able to drop a roll-off trailer and hook to a dump, flat bed, or open-top [trailer] and keep your power unit running, but this requires the operator to have a Class A CDL,” he says.

One manufacturer of roll-off trailers says his company has addressed space and maneuverability concerns by engineering shorter, more nimble trailers that still handle a sizable payload. While roll-off trailers typically are 40 feet long (and up to 47 feet long in Michigan), “what we’re making now are trailers that are only 26 feet long that go behind a power unit [a tractor] and can do everything a roll-off truck can do, but better,” he says. “They’re only about 12 inches longer than a roll-off truck, but they pivot, so they can get into tighter spaces. And because of how we set up the axles, they can carry 50 percent more weight than a roll-off truck in many cities and states.”

Another new type of trailer addres­ses growing concerns with violations of the federal safety limitation of 80,000 pounds for gross vehicle weight, he says. “The trailers that were built 20 or 30 years ago were very robust and could pick up 100,000 pounds, which was both illegal and dangerous,” he says. “New trailers can pick up 60,000 or 70,000 pounds, which is still illegal, but they’re engineered to weigh less—about 16,500 versus 22,000 pounds, so they can [legally] carry more. We reduce the weight by using a ‘stinger’ tail, which allows us to use one less axle and one large reeving and lift cylinder rather than the two medium-sized cylinders we use on our conventional trailer.”
According to this manufacturer, the trailer also accommodates larger roll-off boxes. “The standard roll-off box is a 20-, 30-, or 40-yard box—they’re all 26 feet long, 8 feet wide, but different heights. This trailer will handle up to an 80-yard box, which is 36 feet long, 8 feet wide, and 8 feet high,” he says. “An 80-yard box empty is about 11,000 pounds, whereas a 30-yard box is about 5,500 pounds. You’d typically go with the bigger box because you need the volume—when you have lightweight material but a lot of it.”
Gondola trailers have gained in popularity in recent years, as Department of Transportation requirements for hauling crushed cars have become more stringent, operations managers say. Haulers previously transported crushed cars on flatbed trucks, but in some states, the DOT now requires that they be carried in a container with sides enclosed at least by netting to keep scrap from falling out. The Midwestern director of operations says that his scrapyard has “gone to more gondola trailers” [for crushed cars] since the rule change “because we feel they’re a safer alternative compared to the netting. There’s less risk of scrap falling off the trailer and hitting a passenger vehicle or something else.”

One manufacturer of gondola trailers says his company has seen increased demand because of the stricter regulations. “For a while, we saw smaller scrapyards building their own gondolas and mounting them on flatbeds, but they seem to be moving away from that, mostly because of the extra weight involved,” he says. Further, “if your trailer doesn’t pass a DOT inspection, it can generate an audit. Inspectors will be looking at aftermarket axles and other aftermarket components. If a small scrapyard is just welding something together on its own, it might not be as safe or as structurally solid as a trailer coming out of a factory.”

Outbound Trailers

The Midwestern operations director says his company generally uses vans, walking-floor trailers, or dump trailers to ship processed scrap, and these tend to be longer hauls than its pick-up runs. “We tend to buy scrap locally and sell it more regionally,” he says. “Once it’s a finished product, it can travel further than we’d be willing to haul it as a purchase. Partly that’s because of the value—processed scrap is worth more because the worthless material has been removed. It’s also a matter of customer service—you want to be able to get to your customers’ location quickly and efficiently when they need you to.”

The gondola manufacturer has noticed a trend toward dump trailers, especially in the South and Southeast. “Dump trailers are starting to become more prevalent because companies are trying to use their labor more efficiently, and you don’t need to use a grapple to unload a dump trailer. It’s quicker because you’re basically dumping and going,” he says. “What we find up North, when they’re looking to transport [shredder] fluff to the waste facility just to get rid of it, they’re concerned about uneven ground in a waste facility where they’d be dumping. There are labor efficiencies with a dump trailer, but unless you have a really good operator, there’s a greater risk of tipping a dump trailer.”

Some scrapyards opt for tub-shaped or rounded-bottom dump trailers, believing they empty more easily. Others say the rounded bottoms are helpful when dumping gravel or aggregate but offer little benefit for dumping scrap metal. While gravel is homogenous and has no voids in it when loaded in a trailer, scrap has a lot of voids and can hang up on dents or holes in the trailer, the Midwestern operations manager explains. “Homogenous scrap such as busheling, shredded scrap, [and] nonferrous aggregate all would flow well out of a dump. Non-homogenous scrap such as heavy melt, cut grades of ferrous scrap, [and] aluminum siding would not dump well,” he says.

Walking-floor trailers are either open-topped gondola or van trailers with hydraulically driven slats on the floor that “walk” the material out the back of the trailer. “The use of [walking-floor trailers] has increased over the past five years, primarily because of the increasing value of the nonferrous components,” according to the Midwestern operations director. “People are using eddy-current systems to separate the nonferrous materials in house instead of taking them to a centralized processor. The walking-floor trailers let you get a lot of volume [in the trailer], and nonferrous materials don’t tend to be as heavy as ferrous scrap.”

Several recyclers said they seldom use walking floors for metal scrap, however, because the material tends to get caught in the slats. One trailer manufacturer says he typically sees them only as transfer trailers or as stationary bunker-type units at recycling facilities, where processors use them to move materials inside the plant.

Weighty Issues

Because regulations limit GVW to 80,000 pounds in nearly every state (Michigan being a notable exception), and because scrap companies want to maximize the payload when hauling product, trailer manufacturers have sought ways to reduce the weight of their equipment through design and materials changes. Although the industry has welcomed these efforts, several people say the results have not been completely successful.

Steel versus aluminum. One way trailer makers have tried to reduce weight is by substituting lighter materials for the traditional steel frame and containers. At least one manufacturer produces dump trailers using aluminum for both components, which it says makes them lighter without sacrificing strength.

 “With aluminum there is obviously a weight savings,” says the scrap hauler that also makes trailers, “but buyers have commented to me that the price they had to pay for the trailer versus the weight savings was not what they had expected. As for durability, time will tell, as they are fairly new to the market. Steel frames are still the most popular, [and] steel frames continue to be [the] industry norm.”

The Midwestern operations director explains why his scrap company has stuck with steel: “The reason we’ve stayed away from [aluminum] is that it’s more complicated to repair them. Aluminum frames are also more expensive. If we have a steel frame trailer that cracks, we have the capability to weld and repair it. If an aluminum trailer cracks, that’s a much bigger challenge for us and, I think, other scrapyards.”

Lighter steels. Some trailer manufacturers have addressed the weight issue by modifying the steel they use. “We use a special steel called Hardox, which is very durable but also relatively lightweight,” says one manufacturer. “We know that the tare weight may be a little bit higher than if we included aluminum components on the trailer, but we also know our units are going to last. As a steel material, Hardox can be welded and repaired without any special techniques or equipment. It’s a specialized AR-450 material that is not only durable but has memory—it can flex and come back.”

Frameless trailers. Another way to reduce trailer weight is to eliminate a separate steel frame. One company makes a frameless roll-off trailer, introduced in 1965, that it says can carry up to 8,000 pounds more payload than other roll-off trailers. It and several other companies produce frameless dump trailers as well.

As with aluminum trailers, though, some have questioned the frameless units’ benefits and suitability for the scrap industry. “A frameless roll-off trailer is not as stable,” says one trailer maker. “We used to make one, but it wasn’t accepted in the market, and the main reason was the lack of stability. Frameless dump trailers can work well for certain applications—it depends on the materials they’re dumping and where they’re dumping. If the materials are more uniform and flowable, they’re less likely to hang up during dumping and cause shifts.”

 “Frameless trailers are used more commonly in agricultural applications, where the density of the loads is more consistent and it’s harder to misload it,” the Midwestern operations director says. “Without a frame, the trailer is less stable and more likely to lean to one side if the load isn’t properly balanced inside.”

Michigan specials. Michigan is a special case for trailer options because the state does not impose the 80,000-pound GVW limit. There, as in Canada, trailers can carry more weight as long as the load is distributed over several axles. This exception has led manufacturers to produce trailers up to 50 feet long with as many as eight axles. According to one manufacturer, the price for these largest trailers—with a legal GVW of 137,000 pounds—starts at about $95,000 and can exceed $100,000 with upgraded lighting and other options. For scrap companies operating in these areas, however, the significantly higher cost of these trailers can be offset by larger payloads over their service life.

Options to Consider

In addition to offering the various configurations and sizes discussed above, manufacturers of trailers serving the scrap market offer smaller, basic-level trailers with standard equipment, which buyers can upgrade with options, some of which come as standard equipment on the company’s other models.

LED lighting is still an option on some trailers, though sources suggest it’s quickly becoming the industry standard. Air-ride suspension systems—an upgrade over standard spring suspensions offered on both trucks and trailers—cost a few thousand dollars extra, but they can reduce vibration and improve driver comfort on long hauls. Drum winch hoists are still standard on some smaller roll-off trailers, but larger-capacity trailers use cylinder reeving systems far more commonly.

Some manufacturers have promoted super-single tires as an option to save weight, but dual tires still predominate in the scrap industry. “If you get a flat on a dual tire, you can go back to your yard or maintenance facility to fix it, while with a super single, you are down,” explains the Midwestern operations director.

“Many of us haulers would like to move into [super-singles], but, to be frank, the mills we deliver to and the scrap processors we work for do less than the best job at keeping roadways and scrap pads clean,” adds the scrap hauler and trailer maker. “Super singles are far too costly just to ruin [them] with punctures due to scrap.”

Kenneth A. Hooker is a writer based in Oak Park, Ill.