Transfer trailer specifiers seek equilibrium between payload capacity and durability in an attempt to maximize profitable hauling.
Municipal solid waste haulers are increasingly striving for flexibility in their operations, and transfer trailers are key pieces of equipment for implementing a flexible operation. Fortunately, MSW managers now have more flexibility than ever in specifying transfer trailers. And it’s a good thing, because several haulers who recently spoke with MSW Management say the most significant trade-off they face when specifying transfer trailers is balancing payload capacity versus maintenance requirements.
As in any trucking business, payload is the name of the game when hauling municipal solid waste. Maximizing truck utilization means maximizing the profit margin per truckload. But truck utilization is also about keeping trucks running, period. The more durable the floor and sidewalls, the more time the truck stays on the road and the less time it spends in the shop.
The problem is that maximum payload capacity and minimal maintenance are, to some extent, mutually exclusive goals. Some haulers have found that available trailer components provide both performance characteristics to a degree, while others have to prioritize one over the other according to particular situations.
An Elusive Equilibrium
Because they take a tremendous beating during both the loading and unloading processes, sidewall material and design are major considerations. Weight reduction is important, too. Some haulers think that the marketplace has provided them with equilibrium between structural integrity and weight savings.
Jack Yingling is fleet manager at Kephart Trucking in Bigler, PA, based in the north-central part of the state. Kephart operates three remote waste-processing facilities: Evansburg, PA, to which the company long-hauls waste from the New York–New Jersey area; Laconia, NH; and Grand Prairie, TX. Yingling manages a trailer fleet of about 500 units, including about 400 transfer trailers. At the beginning of 2007, the company purchased 24 transfer trailers from East Manufacturing Co. and another 10 from Mac Trailer Manufacturing.
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| Jay Alexander, general manager of the Wayne County (PA) Landfill, specifies aluminum wall panels. |
Structural integrity was at a premium for Yingling and Kephart. “The most damaging thing to the life of a trailer is the loading procedure—90% of damage to trailers happens at the loading facilities,” he points out. “With over-the-top loading, you’ve got buckets involved and cranes, and it’s very easy to damage a trailer, the top rails, and things. That’s where 90% of your damage is. With any manufacturer, I always look for the design of the top rail on the trailer—that really takes a beating. There are some things in newly designed transfer stations that limit [damage from buckets], but it still is always a concern.”
Yingling and the company opted for Genesis Smooth Walls on its eastern trailers. The walls are designed with a top rail that is flush with the outside of the wall but that overhangs the inside edge for added strength and protection against loading damage. The wall panels are 2 inches thick, reinforced with internal ribs spaced every 3 inches, and continuously welded together vertically. The double-wall design protects the outer walls against dents to enhance resale value. Three-inch spacing on the ribs is said to provide eight times more support than external posts at 25-inch spacings. Cross-members and floor plates interlock into the bottom rub rail to form a pocket into which the sidewall panels then interlock; the convergence is designed to strengthen a critical stress point.
“Ultimately, our feeling is that the Genesis style is stronger; it also has the advantage, particularly in our long-haul division, of a better fuel mileage profile because of less wind resistance,” Yingling says. One trade-off he has had to accept is that the trailer is slightly heavier than other available aluminum trailers.
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| As in any trucking business, payload is the name of the game when hauling municipal solid waste. |
Wayne Roskop, the Spartanburg, SC–based director of maintenance for First Tee Transport of Roseboro, NC, indicates that weight savings were a higher priority than structural integrity when he recently specified four new trailers for his fleet of about 380 for hauling MSW and construction and demolition (C&D) material in the Carolinas, Georgia, and southern Virginia. For this reason, he always specifies fully aluminum trailers. “Everything we run is aluminum; we do it for weight so we can get more payload,” he says.
Still, he always makes sure to have wear plates built into the rearmost 20 feet of the sidewalls. “That’s where you get the majority of the wear on your trailer—where the garbage is exiting the trailer,” Roskop says. “The loading will give you the beating on the top rail, but [as for the] the walls, you’re going to get it because [loads are] very abrasive and you’re trying to take the garbage and push it along the wall.”
Mark Cole, owner and president of M&T Trucking in Pavilion, NY, notes that, because his operations are confined to Upstate New York, M&T’s trailers from Mac Trailer probably take more punishment in hauling 600 tons of waste a day than those of most MSW haulers. He believes he’s getting a happy medium of durability and light weight in his fleet of 50 transfer trailers. “A lot of people unload once or twice a day; we unload six to seven times a day, so we run the last half of the trailer with one-quarter-inch sidewalls. That gives us longevity,” says Cole, who has purchased about 35 new trailers since mid-2006 due to company growth.
Durability and Low Maintenance
Many companies haul C&D material as well as MSW, placing durability at a premium for their transfer trailers’ floors. Also, some of their trailers have to be equipped with moving floors due to landfill requirements; brand loyalty plays a major role in specifying these types of floors.
Jay Alexander is one manager who places a high priority on floor durability. He is general manager of the Wayne Township Landfill, which is owned by the Clinton County Solid Waste Authority and serves about a 75-square-mile area in central Pennsylvania. “We process about 150,000 tons per year, but the supply of space outweighs trash,” he says. “That’s what made us launch our hauling business with transfer trailers. We also do a lot of C&D hauling, so contractors don’t need trucks, permits, licenses, insurance, and drivers. We have eight tractors of our own and 22 transfer trailers.”
The landfill bought three new transfer trailers in 2007 and has bought two or three of these units in the past four or five years. Alexander feels that the engineering of the aluminum sidewalls on the landfill’s J&J Truck Bodies and Trailers units gives them sufficient structural integrity to equal or exceed the life of steel trailers. But the punishment from the C&D material prompted the landfill to devote its new trailers to C&D. “With all of the demolition that we’re hauling, we’re tearing floors up, and they’re a minimum of $10,000 apiece to replace,” he says. “We needed something to get a longer life out of the floor.
“He and I sat down and I explained to him what some of our problems were,” Alexander says of his sales representative. “Fuel mileage was one, floors that were taking a lot of abuse, and capacity—meaning cubic-yard capacity. The price needed to be competitive, but we needed to gain efficiency on fuel economy; we needed to gain efficiency on tons per load; and we needed to gain efficiency on the life of the floors.”
The sales representative’s proposal included Keith Manufacturing’s steel V-Floor, which has ridged slats that withstand contact from C&D material; J&J’s smooth wall panels designed to improve aerodynamics; and 115 cubic yards of capacity. Alexander thinks that the V-Floors will solve his most pressing trailer durability problem—floor damage. “The bottom V doesn’t move; it’s fixed to the floor,” he notes. “The top floor is what does the walking, so you’re trapping liquids, sand, and material that would lie at the bottom of the standard moving floor and either seep through or get in between the slats and tear the rubber seals out.”
From now on, Alexander envisions using the new trailers for tough C&D loads to save wear to the rest of the trailer fleet. “We thought we could probably lengthen the life on the rest of our trailers by having a few V floors and just planning properly,” he says. “You give up some weight with the steel, but we thought that if we had a few of those trailers in our fleet, we could schedule accordingly with these demo contractors, put those floors in when the abrasive material is there, and extend the life of the rest of our trailers. That’s why we bought three at once.”
Other haulers have conventional slatted moving floors on some of their trailers to handle situations where transfer stations cannot accommodate tipping trailers. Moving floors use a conveying system that deploys the slats under a load by pushing them into a side-by-side position toward the front of the trailer. The slats then are pushed toward the back of the trailer and pull the load along until it is unloaded.
“In Upstate New York, they don’t use tippers in the landfills,” Cole points out. “The thing up here is that we don’t have the same size of landfills that they have in the Midwest. I don’t think they have the working space capacity to get a tipper in there. We’d love to use tippers because you get more payload, but it’s not an option here in the Northeast.”
M&T’s transfer trailers use Keith high-rib Walking Floors. “It’s a high-impact floor, and there again the reason we do that is that we’re doing multiple loads in a day and we need the wear structure that’s been very, very good,” he says.
Similarly, Yingling needs to equip part of his fleet with moving floors. “In the cases where I use the moving floors, normally at the customer’s request or the landfill’s inability to tip the trailer, normally it would be smaller jobs where it would not be financially prudent to bring in the tipper.”
Gary Gray, owner and president of Gary W. Gray Trucking Inc. in Delaware, NJ, prioritizes payload capacity when specifying floor material on his company’s transfer trailers. Gray Trucking runs about 600 trailers, some of which are tippers and others of which use moving floors. The company hauls about 7,500–10,000 tons of both MSW and C&D every day and operates a demolition division as well. “We’re constantly buying transfer trailers,” says Gray, adding that his company has purchased more than 1,000 units from Mac Trailer. “We’re constantly buying just because of attrition.”
The nearly 100% aluminum trailers give the company sufficient durability, Gray adds. “Everything’s aluminum; the only thing on our trailers that is not aluminum is the suspension and the upper coupler plate area,” he says. This includes the Keith Walking Floors. “There’s no sense in us sacrificing. Weight is the most critical issue for us—if we can take a few pounds out of a trailer, we do that. We’re so weight-conscious that we literally specify everything that goes in a trailer once we figure out what works for us to keep the weight down to a minimum, so that’s why we stay away from steel.”
Roskop specifies Hallco moving floors for his transfer trailers when possible. The reason is ease of maintenance. “As far as maintenance needs, it’s the easiest floor to work on,” he says.
Although the majority of his fleet consists of tipper trailers, Roskop says that he has about 60 moving-floor units. These floors have snap-on slats for quick installation and replacement, and the floors are constructed as single units. The length, width, and thickness of the slats are designed according to the hauler’s common applications. During operation, a two-way hydraulic power unit moves the slats in unison, and the slats take the load along with them. As the slats are returned to the starting position, every third slat in the floor moves in unison while the other stationary slats hold the load in place until the next cycle starts.
Experience Shapes Preferences
Experience operating their transfer trailers in off-road conditions some of the time has shaped these managers’ preferences of suspensions. Ease and amount of maintenance are major factors in choice of suspension.
Cole has enough confidence in the durability of his trailers that he specifies spring-ride suspensions. “A spring-ride suspension typically can be kind of hard on a structure because of the pounding versus the air ride, and I agree with that,” he says. “The air ride is definitely easier on a trailer, but we also do a lot of drop-and-hooking, and the dolly legs with the air ride sometimes can be a dangerous situation.”
Cole’s trucks use Reyco Granning spring-ride suspensions exclusively. “We really like it,” Cole says. “It’s durable. We have a time or two that we have to replace a spring, but for the most part, the bushing life in it has been very good to us, and parts are very accessible and easy to go with.”
“Modern air-ride suspensions, from a ride standpoint and driver feedback, are pretty equivalent, but from a maintenance standpoint we firmly believe that we can maintain a spring-leaf suspension for less money in this work environment,” adds Yingling, who specifies the Reyco Granning 21B suspension. “It just seems to be the most durable for us and also the easiest for our maintenance staff to maintain and repair. It’s lightweight and yet has good durability, particularly with live floors.”
Durability is also the key for Roskop in specifying spring-ride suspensions. “Everything that we build is basically [spring ride], just to take air bags out of the issue; and being in landfills, it’s one less thing to get damaged or punctured,” he says.
An all-other-things-being-equal view of less-expensive spring-ride suspensions has prompted Alexander to specify this type of suspension for transfer trailers. “We run all-air-ride tractors to start with, so when we start looking at the trailer suspension, in our eyes, it isn’t as crucial because we have the air-ride suspension,” he says. “We’ve got the driver pretty well isolated from the abuse and the vibration. The air-ride suspension we have confidence in, but it was basically an economic decision. We looked at the overall price of how we originally specced it out, and we needed to back off a little bit.”
Air ride is the suspension used on Gray Trucking’s dump trailers and tankers, which occasionally haul liquid waste. For the company’s transfer trailers, though, the spring-ride type is the suspension of choice. “We standardize on a Reyco 21B suspension with single leaf springs,” he explains. “We’ve found that suspension to be very stable; it doesn’t have a tendency to lean in the corners. The durability of it and the ease of maintenance is the key. It’s been around for a long time. It’s pretty simple with cast steel–type hangers; the durability and weight savings and the longevity are good.”
Results of Choices
Ultimately, the driving force behind these purchase decisions is economics. These managers point out that the choices of these components have directly affected the bottom line.
For Gray, the positive results of his purchase decisions emerge when it comes time to sell his used trailers. “Optimizing my payload and then the resale value when we get done with them” are the biggest benefits he reaps from his choices. “When we go to get rid of them, we have no trouble getting top dollar. People know our fleet, and they’re pretty anxious to buy our stuff. Once in a while, for getting rid of a group of, say, 10 or 12 in a shot, I’ll take them to an equipment auction someplace, and they just blow the others away in price.”
He adds that while the company is utilizing the trailers, going as light as possible on tare weight has resulted in measurable profitability per load. He says that Gray Trucking loads every tractor-trailer to the maximum 80,000 pounds and that an additional 200–300 pounds per load that is yielded by a lighter tare weight, multiplied by 300–400 loads per day, adds up to a significant aggregate payload.
M&T Trucking has experienced great strides in profitability due to lower maintenance costs on its trailers, Cole says. Because the company limits its operations to the state of New York, cubic yardage per trailer is what really counts under the state’s divisible overweight permits, he points out. “We’ve never really looked at a really small tare weight because we can never get to our maximum permitted weight anyway,” he says. “So we’re looking for structural strength, because we’re hauling the heavy loads and we’re maximizing the cubic yardage of the trailer, and we look for durability more than the weight. We’re looking for durability.” His transfer trailers have certainly delivered on that count.
“We don’t have to work on the structure of the trailer at all,” he says. “We do the dings and things that happen here and there, but as far as structural breakdowns, there are virtually zero. The longevity is there and it takes us from having to run it through the shop every two months to where we can go every six months and run it through and do a complete makeover on it.”
Yingling believes that 15 years of specifying transfer trailers has allowed him to actually budget for maintenance costs with reasonable accuracy, because Kephart has entered the realm of preventive maintenance—the ideal in any business that uses heavy equipment. The benefits the company has gained are “a combination of the ability to haul bigger legal payloads and still keep your maintenance costs to the profile you’ve put forth when you first estimated the job,” he says. “In particular, with these trailers, we feel that we have as bulletproof a trailer as we can build with what’s available on the market right now. And we have a good handle on those maintenance costs and have the [cost] controls that we need.”