In the face of long, grueling hauls and tough environments, fleet managers are able to keep their MSW transfer trailers rolling year after year.

By Charles D. Bader

With today’s longer and longer hauls of MSW from local transfer stations to distant landfills, the demands on transfer trailers have never been greater. And these demands are conflicting. On the one hand, there are significant advantages to reducing the weight of the trailers to an absolute minimum and thereby maximizing the payload possible under the legal over-the-road limits. On the other hand, transfer trailers are expensive, so haulers want them sturdy enough to withstand the combination of long, high-speed highway hauls and the often rough handling of MSW (or worse, C&D debris) at the landfills.

“It is inevitable that damage will occur to the trailers,” says Philip J. Bortz, vice president for sales and marketing at Mac Trailer of Alliance, OH. “After all, the waste industry traditionally is one of the most abrasive applications for equipment and subsequent maintenance. However, the level of damage can be minimized by looking to the trailer manufacturer as a resource that can draw from a history in understanding a hauler’s particular application and subsequently build a trailer that will best serve your needs.”

Too often, it would appear, haulers opt for the operational savings of the lightweight trailers, and they take their chances on how much damage their trailers will sustain and how much repairs and early retirement of the trailers will cost them.

Sidewalls of 5/32-inch aluminum on posts 2–3 feet apart certainly risk damage from loading and unloading. In fact, only Trinity Trailers of Boise, ID, makes its entire line out of steel. Trinity’s John Christofferson gives three reasons: “Steel is much more flexible and resilient than aluminum, allowing the trailers to flex without cracking, even in tough off-road applications. Steel is easier to repair or rebuild. Most all repairs and maintenance can be done anywhere with a common torch or welder. You don’t need huck bolts or rivets, which are commonly used when repairing aluminum trailers. And stainless steel stands up to damaging road salts and is far superior to aluminum when handling corrosive loads. Stainless steel won’t dissolve or pit like aluminum.

“Combine the advantages of steel with our unique frameless design, and you have a trailer that is remarkably light in weight, with superior strength and flexibility, and that will retain an uncommonly high resale.”

However, as Mike Riggs, product manager of J&J Truck Bodies in Somerset, PA, points out, “Weight is a key factor causing haulers to opt for aluminum. And even just increasing the thickness of aluminum to a quarter inch adds about 700 pounds to a lightweight trailer. That’s a significant reduction in the MSW payload that a hauler can legally carry over the highway. So it’s usually only a fleet manager who faces a particularly difficult situation involving perhaps five or six loads and unloads a day and a difficult environment who will opt for quarter-inch aluminum sidewalls or steel sidewalls. Most everybody goes for the lighter-weight walls.”

A relatively new trend is the use of extruded-aluminum panels—constructed like a hollow-core door—rather than the usual post-and-panel design. Such manufacturers as J&J Truck Bodies and East Manufacturing, of Randolph, OH, include these smooth work models in their lines, but it is Titan Trailers of Delhi, ON, Canada, that commits its entire line to its “Thinwall” design.

“Thinwall modules have aluminum sheets attached to interim posts so that there are aluminum sheets both on the interior and the exterior of the trailer,” explains Mike Kloepfer, president of Titan Trailers. “We use horizontal rather than vertical panels, with the interior ribs running the length of the trailer side. The thickness of the aluminum sheet is determined by the application. We offer four different panels with skins as thin as 3/32 of an inch or as thick as 3/16 of an inch. The horizontal ribs are much closer together than are the vertical ribs in a typical post-and-panel design, so it makes our panels much more resistant to big tears. Titan live-floor trailers are the most expensive on the market, but they offset their additional purchase costs by providing up to 10% more cubic capacity and earn fuel savings of up to 15% compared to post-and-panel trailers.”

Jack Yingling, fleet manager of Kephart Trucking, in Bigler, PA, confirms that claim. Although his 350-trailer fleet has four different brands of trailers, most recently he purchased smooth-sided trailers. “I paid about 5% more for them,” he says, “but it looks like they pay off in fuel mileage and durability. As a result, we are moving in that direction.”

Moving-Floors vs. Tippers
Another area where the quest for low weight is beginning to dominate is in the design for moving-floor trailers, once the standard of the industry. They are now being supplanted by tipping-platform trailers. Mark Sabol, product manager of solid waste equipment at East Manufacturing Corp., of Randolph, OH, says that the company’s sales of tippers are now approaching those of moving-floor trailers. Riggs of J&J Truck Bodies goes even further, stating that 80% of his company’s trailer sales are aluminum tippers.

Many haulers have become advocates of belt-driven systems.

“This is remarkable, when you think about it,” Riggs says. “Since tipping mechanisms at landfills cost $250,000, few haulers can afford to own one. Therefore, they have to wait in line while landfill operators do the tipping, and I presume they pay plenty for the service. But the trend toward tippers is unmistakable—80% vs. 15% for moving-floor trailers.”

Sabol explains the reason simply: “Not only are moving floors expensive,” he points out, but they are heavy, weighing about a ton and a half to two tons more than a tipper trailer. “That’s a lot of payload lost for haulers operating on thin margins. Even though a hauler with a moving-floor trailer can unload quickly and without waiting at the landfill, a ton and a half of payload lost on every haul represents a lot of money lost.”

A compromise solution is offered by  Christofferson, who says, “Trinity trailers have a low-maintenance conveyer unloading system, consisting of tough, flexible pieces of conveyer belt attached at the leading edge to high-tensile–strength steel pintle chains. This creates a continuous yet flexible chain and flap belt inside the trailer bed.”

Rich Grant, of Rich Grant Trucking Company of Ogden, UT, has been leasing trailers from Trinity and is a strong advocate for the company’s belt-driven unloading system. “We can unload an entire trailer in just five minutes,” he says. (Rick Franklin of City Recycling in Portland, OR, claims his drivers can do it in three minutes.) “The belt-floor system works just great, and they weigh only half what a moving- (shuffle) floor unloading system would cost,” Grant goes on to say. “Weight was an important factor in our 42-mile haul. We had to be right on the money, hauling 24.5–25 tons on each haul every day.”

With few exceptions, then, most haulers are opting for lightweight, inherently fragile trailers for frequent hauls involving loading and unloading every day. Despite the risks of this approach, however, haulers and trailer manufacturers alike predict that haulers will use their trailers for seven to eight years, and that after they sell them (to what continues to be an active secondary market), secondary haulers with less stringent requirements can expect another four or five years of useful life.

How are haulers achieving this? “There always seems to be a second, third, fourth, or even fifth life for such trailers,” Bortz says. The value continues to be determined by the year, condition, construction of either steel or aluminum, and severity of the applications for what it will be used. The balance of this article describes what wears out and what manufacturers and haulers are doing about it.

Beware of C&D Waste
Occasionally, haulers can use the same trailer for several different applications. Every day, for example, Franklin’s trailers take MSW to the landfill, load up boiler fuel and take it to the incinerator, and take wood chips to a recycling center. However, most haulers of MSW do not use these specialized new trailers for anything else—specifically C&D debris.

Grant recalls that his hauling company was using a trailer model designed for MSW to haul C&D. Not only did the heavy chunks damage the steel sidewalls, but they also damaged the belt. “Usually we’d bend back the damaged sidewalls and crossbars, but sometimes we’d have to replace parts. The MSW never damaged anything.”

Yingling had similar problems with C&D waste but developed ways to find out exactly what the trailer would be hauling. “As long as we know what we will be hauling,” he says, “we can apply the proper loading procedures.”

Work With Operators
Since haulers are at the mercy of loading personnel at the transfer station and unloading personnel at the landfill, damage during these operations is outside their control. However, there is a way to mitigate this problem. Christofferson of Trinity Trailers suggests the following: “While our trash haulers have heavy-duty tarp bows, they can be damaged by careless loader operators.

Today, the load demand on trailers is greater than ever before.

Same for tarps and top rails. I’ve noticed that trailer owners who have control or influence over the loader operators seem to enjoy longer trailer life and have fewer overall repairs. If a loader operator knows there is a large chunk of concrete that must be loaded, he can add to the trailer life by loading a cushion or layer of garbage prior to lading the heavy piece of debris. Dropping large chunks of concrete or heavy metal objects onto the bare floor of a trailer will accelerate its repair cycle and reduce useful life.”

 “The problem is just as bad at the landfill when landfill personnel are operating the tipping platforms,” Riggs says. “If the operator tries to dump the load too fast, he may tear up the rear end of the trailer and/or the landing gear. I’ve seen some operators damage landing gears by bouncing the trailer to get all the MSW out, and I’ve seen them blow the gate right off because they forgot to raise it first. The hauler has to just stand there, so all he can do is try to develop a relationship with the landfill operator so that he understands the proper unloading procedure.”

Yingling has achieved that relationship with the three or four major landfill operators Kephart hauls to.

“We now can exchange information and ideas that will improve the total disposal operation and work together. Every day the situation gets better and more cost-effective.”

Maintenance
MSW haulers take maintenance seriously. To a man, they follow the manufacturers’ service manuals as well as the federal CDL safety requirements. And Bortz concedes that while preventative damage-control measures can be taken at time of spec review and manufacturing of the trailer, a structured preventive maintenance program becomes a proactive daily measure that can reduce repair costs and extend the life of equipment once in operation.  Some haulers go beyond the PM programs recommended by the trailer manufacturers. For example, Phil Harless of Valley Aggregate Transportation in Sacramento, CA, insists on a pretrip inspection of tires, lights, cracks, lugs, tightness, coolant levels, and air pressure, in addition to a rigorous 90-day PM schedule. Yingling says Kephart has two maintenance shops that operate year-round, 24 hours a day, in order to support drivers with any maintenance issues that may occur. Its PM schedule is 30 days. City Recycling also maintains its own service, inspects trailers every day, and greases and inspects brakes every 5,000 miles. In other words, they all take care.

Specification standards have evolved over time in terms of function and versatility.

But of course even the best maintenance program does not preclude incidents that damage even the sturdiest transfer trailers. When questioned as to the most likely parts of the trailer to be damaged, the haulers and manufacturers interviewed for this article identified trailer walls, toprails, and floors.

Aluminum sidewalls are particularly prone to damage, although steel sidewalls are not immune either. The loading process by transfer station operators using loader buckets or clamshells can gash the aluminum and bow the walls out. (Harless complains that rivets on the inside post give and have to be replaced.)

According to Sabol, the rear 4 feet or so of the sidewalls are at greatest risk, and he says haulers often add 4-foot-high overlays to the sidewalls to protect this area. “Some haulers add the overlays as soon as they procure the trailer,” he says, “but every hauler should inspect this area and add overlays before the wall structure is too badly damaged.”

Christofferson agrees, saying, “We typically line the floors and inside walls with 3/8-inch HMW plastic. This liner serves as protection, but also ensures the load will not freeze to the walls and will unload cleanly and smoothly. While rare, the consistency in trash and wood debris is such that you never know when some jagged or unusual object will gouge or damage a liner. Most loads usually undergo some type of screening or sorting, and most liner life is ultimately determined by the abrasiveness of the loads over time. We can weld simple cuts or holes, but if the damage warrants liner replacement, it, too, is a simple process.”

Construction debris is one of many heavy substances with which haulers must contend.

While Kloepfer insists that extruded smooth-wall panels resist all but the most severe damage, such as that caused by a fire or a trailer rollover, Titan has taken steps to allow ready removal and replacement of sidewall panels. Kloepfer estimates that two men can remove and replace a panel that runs the length of the trailer in about 20 hours. He adds that they also can patch a section of 4 feet or so in 10 hours.

Toprail Repair
The combination of excessive zeal and lack of care on the part of loading personnel at transfer stations can bend out and sometimes break the toprails of trailers. Most haulers can bend top rails back into position, but few have the capability to repair a broken toprail. An exception to that is Kephart Trucking, with its maintenance shops. Yingling says they can repair and re-weld top rails to repair the company’s trailers.

Titan has a unique method that allows ready repair of a broken top rail. The company provides a toprail extrusion that can be cut to the length needed. Rather than remove the broken top rail, a hauler can simply fit and weld the new extrusion on the broken toprail. This way, the trailer is not out of service for a lengthy time, waiting for a new top rail and having it professionally installed.

Floors
Floors don’t wear out quickly, but when they do, the repair expense is substantial. Harless had to replace a floor, so he now takes great care of his trailer floors, keeping his trailers clean of corrosive and abrasive garbage when not in use and doing a daily inspection to detect such things as rivets whose heads have worn off. “We inherited several 1998 trailers when we bought out another hauler,” Harless recalls. “We could see that in one of them, the floor was starting to get thin between the cross members, and we saw that it would soon give way. You can’t go halfway when you replace a floor. You have to take everything out and replace it with new parts. That includes new cross members, wiring, and plumbing. And you coat parts so they won’t corrode. It’s an expensive proposition, but if you do it right, it will extend the life of that trailer for years.”

Harsh Environments
Kephart Trucking is located in the Northeast, and Yingling blames the winter temperatures and harsh salts and chemicals for damage to his trailers’ electrical lighting and wiring. “Over 50% of our maintenance repair orders are for electrical problems,” he says. “Now some of the trailer manufacturers are providing better wiring protection that at least helps avoid open junction boxes.”

Potentially corrosive garbage is yet another maintenance hazard.

Valley Aggregate has a brutal 250-mile route from Placerville, CA, over the mountains and through the Donner Pass to the Reno, NV, area. In the winter, particularly, the combination of low temperatures, snow, and snow melting products combine with the stiff grades to create a problem. Harless says that this twice-a-day regimen causes problems with axles, brakes, and suspensions, all of which can corrode and rust. He has no magic solution for this situation, other than an insistence on top-of-the-line parts and a PM program that includes thorough pretrip inspection and greasing whenever the driver elects to make the journey between the mandatory 45-day service appointments.

Tires: The Big Wear Item
Although tires do not contribute to the useful life of transport trailers, they eat up a large portion of a hauler’s O&M budget. Therefore, controlling tire costs is a significant factor, and most haulers take care to maintain tire pressure and inspect both tread and sidewall conditions thoroughly every day.

One issue that is controversial is whether trailer tires should be recapped—and if so, how many times. All but one of the haulers we interviewed recap their tires. Sabol of East Manufacturing says his hauler customers tend to buy a standard tire, run it for a while, and recap it several times until sidewall damage dictates buying a new one. Riggs of J&J says his experience is somewhat different. “Because tires are so cheap these days, retreading may not be worth the effort.”

Another tire issue is whether to use the newer super-single wide-based tires or stay with the traditional dual-based tires.
The super-singles offer a number of advantages, according to Kloepfer: “They are lighter, so you can carry a greater payload; they are 18-ply as opposed to 14- or 16-ply. You need only two of them per axle, and they offer better fuel economy and longer tire wear.”

Yingling was the only hauler we interviewed who had converted to super-singles, however, and he is one hauler who buys top-of-the-line tires. He says, “The savings with lesser brands have not proved out in terms of wearability and durability.”

Harless also opts for top-of-the-line tires, in this case, the Michelin X2E. But then Harless believes strongly in using only the best (and most expensive) parts. He hasn’t done a cost-benefit study to prove that this policy is the best, but then few haulers do cost/benefit studies. Instead they rely on their experience, and the good performance and long-life of their trailers seem to support their approaches.

Bortz agrees with Harless’s policy and points out that many companies like Valley Aggregate that own and maintain their transfer trailers have established a “standard” set of specifications that have evolved over time for functionality, versatility, and of course the tradeoff between structural design versus weight of the trailer. “And,” Bortz says, “such initial investments to have a stronger trailer have paid return dividends over the years from reduced maintenance costs and higher resale values years later at the time of trade or sale. The more intimately the trailer manufacturer understands what may be unique to a hauler’s application, the better assured that hauler will be that he will have a trailer built to withstand the abuses associated with his haul.”

Based in Los Angeles, Charles D. Bader writes on diverse technical topics.

MSW - September/October 2006