Transfer operations are characterized by mechanical and chemical deterioration of two of MSW managers’ most important capital investments: transfer tractors and trailers. Several professionals who spoke with MSW Managementhave accumulated years of experience that guides them in specifying equipment that makes their operations work as efficiently and as cost effectively as possible. One thing is certain in regard to specifying this equipment: One size or feature definitely does not fit all.
Driver Comfort, Durability Valued in Tractors
Transfer hauling is a hybrid between over-the-road and vocational trucking. Even if the driver is on the highway for 80% of a given haul, maneuvering the truck at a transfer station or landfill—or on side streets—can cause a great deal of repetitive motion and uncomfortable body positioning. The King County, WA Solid Waste Division, which services seven transfer stations with more than 50 Kenworth T800 tractors equipped with Caterpillar engines and 160 trailers, places a high priority on the driver comfort and safety that its transfer truck tractors afford, points out Ken Stephenson, division procurement program manager. This is largely because the service area of about 1.3 million is characterized by significant traffic congestion.
“[Ergonomics] is a big factor for us,” he says. “We’ve specced out a particular size of cab, and the Kenworth has worked out for us as far as ergonomics and space in the cab for the operator.” Adds Terry Brown, division shop lead, “We’ve got various sizes of drivers—tall ones, shorter ones, and big-around ones, and it works well for us. We’ve even got two automatics in the fleet now.”
|Photo: Mac Trailer
Durability and light weight are high priorities in transfer trailers.
Many of these comfort and ergonomic enhancements have been specified as a result of the division conducting driver surveys when the time comes to solicit bids on new tractors, Stephenson notes. “We also talk to people who actually repair the vehicles and get them involved in the bidding process—oftentimes, we’ll get feedback from them on what works well, and we’ll spec out a particular [anti-lock brake] system and make sure that we keep the fleet standard.” Brown adds, “We spec auto slack adjusters for the brakes, too. Every tractor and trailer has them. We’ve done everything we possibly can to make maintenance and life easier.”
The surveys have led the division to specify air-release fifth wheels on the tractors. “Those are a thing we’ve added for creature comfort and added safety as well,” says Stephenson. “Any time you keep the driver in the cab to release that fifth wheel, it’s a big help.” “We used to have lot of shoulder injuries because they might hook up the trailer 20 times a day,” adds Brown. “We’ve also gone to air-assist clutches; we have no more knee injuries, either.”
For driving safety, the division has focused on drivers’ visibility. “We went with one-piece windshields, and that really improves the visibility—it’s almost like driving a car,” Brown argues. Sloped hoods and rear corner windows have also helped to maximize visibility, he adds.
Off-road driving affects more than drivers, obviously. Basin Disposal of Pasco, WA, prioritizes frame and cab integrity, according to Darrick Dietrich, general manager. The company uses 13 Peterbilt Model 386 tractors and 24 trailers to haul about 135,000 tons of refuse annually from as far away as 75 miles. An all-aluminum cab is a key factor in the tractors’ low cost of ownership, says Dietrich. For structural integrity, corrosion resistance, and watertightness, the cabs utilize huck-bolt fasteners, lap-seam construction, and bulkhead-style doors.
The light weight of the cab is also intended to yield fuel economy. Dietrich points out that, while tractor manufacturers’ claims of fuel savings are tilted toward over-the-road trucking, the cabs are a contributing factor in fuel savings. “Over-the-road freight carriers are hauling 80,000 pounds in a different environment; all day long, our tractors are pulling 102,000 pounds—we load those trailers to the max,” he says. “The reality is, fuel mileage is nice, but it’s really the integrity of the cab that does it for us.”
Basin Disposal and King County each specify setback front axles for adherence to local weight laws. “That setback front axle helps out a lot,” says Dietrich. “In our trips to the landfill, we cross state lines into Oregon, and each state interprets the federal Bridge Formula differently.” King County’s T800s feature 48.5-inch setback front axles designed to allow the transfer of more of the vehicle’s weight to the front end for maximization of rated capacity.
King County also places a premium on frame durability, Brown notes. Its tractors are continuous straight rail constructed of heat-treated steel, and the gussets and cross-members are made of extruded aluminum for maximum rigidity at minimal weight. Additionally, “We’ve gone to air-ride suspensions and air-ride cabs—that seems to help the whole tractor,” says Brown. “We’ve never had cross-members or suspensions come loose.”
Since 2005, the county has also utilized automatic lubrication systems, to the benefit of frame integrity, Brown reports. “The reason we use them is that the tractors go through a truck wash every day and we found that we were losing kingpins at 75,000 miles,” he says. “Now we go over 150,000 and haven’t lost a kingpin yet. I haven’t had any complaints about the trucks pulling to the right or to the left, and we’ve cut the front-end alignments by more than half. I’ve been the shop lead since 2000, and I’ve seen the change. We used to have to manually lubricate S-cam bushings and S-cams; now we can do a round or two of brake shoe replacements without greasing the bushings.”
Fuel economy and frame integrity are design features of International Truck’s PayStar and ProStar tractors. The PayStar 5900 SBA (setback front axle) model can be specified with single or dual 10.25-inch frame rails to replace the standard 12.25-inch frame rails that can save about 90 pounds, according to the manufacturer. Aerodynamic design features include low-profile fender openings, a precision-designed sloped hood and a minimized bumper gap. A key new development for the ProStar series cabs is a higher-clearance vocational front bumper that became available in fall 2009.
The models will be equipped with MaxxForce 11 or MaxxForce 13 engines that utilize exhaust gas recirculation (EGR) technology, in contrast to selective catalytic reduction (SCR) technology, to meet 2010 EPA emissions regulations mandating reductions in nitrogen oxides. EGR technology recirculates a portion of an engine’s exhaust back to the engine cylinders and burns off excess pollutants. Because exhaust is recirculated into the intake stream, gases displace some of the normal intake, slowing and cooling the combustions process and reducing nitrogen-oxide formation. The PayStar will be available with the 15-liter Cummins ISX engine until about the second quarter of 2010, according to the company.
Trailers: Where Light Weight Meets Integrity
Not surprisingly, professionals who spoke with MSW Management say they place a high value on the same attributes in trailers as in tractors: light weight and durability.
“In our business, we’re moving weight, so the biggest thing with us is having a lightweight trailer but also one that’s going to hold up for us,” says Frank Carter, terminal manager with TAC Transport in Washington, DC, a growing company that was serving Washington, DC, Philadelphia, and parts of Maryland and Virginia with about 200 tractors and 250 trailers as of summer 2009, and that is expanding into New York and New England. “We’re looking to keep trailers for 10 years or better. When we start our spec, we look at getting it as light as we can get it and also getting it to stand up to the pounding.”
|Photo: John Trotti
For many, tippers are a popular choice.
|Photo: John Trotti
Up, over, and out
In regard to the aluminum East Manufacturing Genesis Smooth-Wall trailers that the company has increasingly specified over the past five years, Ron Adolph, president and chief executive officer, adds, “We spent a lot of time going through the spec, making sure that the integrity was there, that it would hold up at transfer stations where, of course, it takes a beating.” But the trailers are holding up well, Adolph says. “We don’t feel like we have to baby them along and not use them in certain situations. We’re a standard waste hauler—MSW and [construction and demolition] are about as far as it goes.”
The trailers have 2-inch-thick extruded sidewall panels supported by internal ribs every 3 inches. According to the manufacturer, the rib spacing gives eight times the support of external posts positioned every 25 inches. Carter acknowledges that the top rails on transfer trailers take a beating from front-end loaders, but the company’s aluminum top rails have held up very well. “Another thing: We used to have a lot of cracks under the frame that holds the tandems up, but we haven’t had any cracks on these frames.” Besides the inherent lighter weight of aluminum, another design feature yields fuel economy, adds Adolph. “[Aerodynamics] is a big priority for us because there are big fuel savings, too. The trailer has provided us with fuel savings—you don’t have side posts holding you back when you’re going down the road.”
TAC Transport still uses steel sheet-and-post trailers for 10%–20% of its fleet, although it stopped purchasing steel units about five years ago. “I look at it depending on where we’re going in, the type of loading taking place—demo versus MSW—I take all those things into consideration. For C&D jobs, I tend to look more at sheet-and-post, but for my MSW, I want to run my smooth sides because you can get your payload and you’re not going through that high stress of loading big concrete blocks or dropping something into it.”
Another benefit is inherent in using aluminum trailers, Adolph says. “The other thing is the appearance on the road. You haul trash, but you don’t have to look like trash. It’s important to us that the sidewall gives us a look and feel on the street that we can be proud of and puts us in good stead as we deal with the DOT and our customers and the communities we serve.”
The Sacramento County, CA Municipal Services Agency, which collects up to about 350,000 tons of refuse a year, utilizes aluminum walls on all of its 39 trailers hauled by a dozen tractors. Matt Tedrow, waste operations manager over transfer operations, says that the superior rigidity of aluminum provides a durability advantage over steel. “Top loading is going to be tougher on trailers than anything, and that appears to be the primary industry method, at least locally,” he says. When possible, the agency bales its refuse using two balers. “We’re just a little different because we made that investment in the baler. When you use an excavator to tamp down garbage, you have a tendency to put pinch marks on the sides of the trailers and possibly bow out the sides,” he says, adding that the steel-walled trailers the agency used to operate were subject to bowing problems. “We’ve been pretty lucky; I’ve gotten eight to 10 years out of our trailers. A lot of that has to do with bailing most of the stuff and just keeping up on maintenance.”
An optimal combination of minimal weight and maximum structural integrity are also high priorities for C&W Trucking Inc. in Winter Garden, FL. The company operates about 75 tractors, 100 live-floor trailers, and 25 tipper trailers from Mac Trailer Manufacturing in serving central Florida and southern Georgia and hauling up to 450,000 tons of refuse every year. Kevin Creeden, vice president of operations, has noticed that on “shuttle hauls” from transfer stations to landfills, trailer tare weight is not as much of an issue. But for situations in which trucks are not empty on either the front or back haul, Creeden says the company has specified slightly lighter-weight trailers. “There are other operations where we actually go into a lighter-weight trailer, what we call a chip trailer—which Mac really doesn’t make—if it’s just for a wood chip business that you don’t need such a durable trailer.”
|Photo: Titan Trailers
A Titan Trailer with a V-18 unloader system walks off a load.
Creeden sees benefits in welded sheet-and-post side panels as well as in the Mac Vertical Panel (MVP) smooth-side extruded aluminum panels, depending on the situation. The company has purchased several MVP trailers for longer hauls for better aerodynamics. However, “We have not yet worn out any of the side panels on any of the [horizontal] sheet-and-post or the vertical post panels we run,” says Creeden. “I’m not saying we don’t have some wear there, but nothing more than standard. We haven’t had any issues with the cross-beams, up at the top and with the tailgate being open. Some [transfer stations] load where they have to reach all the way over the top of the walls; some load with a front-end loader, others are loading with what they call a knuckleboom with a claw on the end. You put that knuckleboom on the inside of the trailer and open it up and pull it back out and you usually end up catching the top rail or cross-beam, and that’s where the damage gets done.”
Like most transfer haulers, C&W Trucking focuses on top-rail reinforcement. “We usually spec a little heavier-duty top rail because we’ve had so much of a problem in the past, and we have not had problems lately. Once in a while, the tailgate gets out of alignment. I can’t say that’s a wear problem—I think that’s a loader damage issue where they hit something back there.”
Key Components: Floors, Tarping Systems
Live floors provide fleets with significant flexibility. Some landfills are not equipped with tippers serving either MSW or C&D, or, in some cases, the tipper might not be available in a timely fashion. Some haulers, like TAC Transport, are trying to serve a new type of customer, and loads must be dumped in locations not originally intended for them.
“We have to have the Walking Floors to go into waste energy plants because, typically, they don’t have tippers,” says Adolph, noting that only about 5% of TAC Transport’s trailers are equipped with Keith Manufacturing’s Walking Floors. The Walking Floor operates in a four-stage process. Floor slats or planks slide underneath the load in groups of three, one group at a time, toward the cab. In the fourth and final stage, all of the grouped slats/planks move together toward the discharge end of the trailer, pulling the load along in that section of the floor.
“I’m sure Frank will say that he likes to have them in the mix because there are days when you like to have some options. The name of the game is tons per load and turns per day—that’s what our business is driven by. We can get more weight on a tipper than on a Walking Floor, and we’re trying to increase the number of tippers we have.” Adds Carter, “On those days when you go into the landfill and you can’t get to the tippers, you like to have your Walking Floors,” he says. “Also, you leave yourself open for specialty work that may show up. If the tipper goes down for whatever reason, you still have that option.”
In contrast, the Sacramento County [California] Municipal Services Agency—a public entity that operates a landfill—uses live floors exclusively. The reasoning behind this specification, according to Tedrow, is financially driven. With live floors, “You don’t have to set up your landfill with a tipper, which is an expensive piece of equipment,” he says. “I’d have to retool the whole fleet. For us, using live floors is simpler because they’re self-contained—you don’t have to drive to the landfill, back the thing onto a tipper, and have the whole thing lifted up into the air. I would imagine there would be some wind and weather conditions where that would actually be hazardous. I think baling is a cleaner operation.”
Noting that live-floor trailers are more susceptible to getting stuck in landfills, Creeden shares a technique that C&W Trucking has discovered for getting trucks unstuck. “If they get stuck in these landfills, usually nobody wants to get out, hook up a chain and walk through the landfill,” he says. “Lately, we’ve been speccing the trailers with pusher bumpers on the back, so if they do get stuck, the compactor can come up behind the trailer, scoop up some garbage against the trailer, and try to push it out. Otherwise, if they if they don’t get square on it and try to push it out from the back end, they might skew the tailgate or something.”
Another major live-floor manufacturer, Hallco Industries, uses a two-way, variable-speed hydraulic power unit that moves the floor and allows for controlled loading, unloading, and precision metering. The deck slats move together, taking the load with them. They then return to their starting position, with every third slat moving in unison. The stationary slats hold the load in place until the next cycle begins. The system features a rectangular steel subdeck designed for high impact strength and the subdeck is also available in aluminum for weight savings. The decking is leak-resistant, with overlapping slats to lock out debris. The bearings have side “wings” that snap into place above the bottom legs of each slat, and bottom lips designed to fit snugly around the subdeck to hold the bearings in place.
A key truck component that limits material loss in transport is a tarping system. Ed Heston, terminal manager with Ruan Transportation in Reno, NV, reports that the company specifies Roll Rite’s side-to-side (STS) Series Systems for its fleet of 17 Peerless trailers, which are hauled by 16 tractors. The company is a contract hauler for Waste Management in Reno, hauling about 600,000 tons through seven Waste Management transfer stations annually. Ed Heston, terminal manager for Ruan Transportation, says the company prefers the STS model, which may provide more trailer side clearance and a higher payload, and which anchors across a ridgepole, over the manufacturer’s Front-to-Rear system.
The system, which tarps trailers up to 53 feet long and 102 inches wide, uses knuckle-pivot technology designed to keep tarp height to a minimum and reduce overhead hazards. It uses a TarpStretcher gear motor designed for side-to-side tarping that stretches the tarp down around lock-down accessories provided with the system’s Axle Kit, which is available with or without ridge poles. Ridge poles are recommended for watertight solid-tarp applications.
“The main reason we went with the side-to-side was Workers’ Compensation claims,” says Heston. He explains that the system eliminates the need for the driver to manually close flop gates with a pole, a potentially dangerous situation in windy conditions. With the side-to-side, you eliminate that completely—the driver just stays in the truck and makes sure the tarp rolls over and stays secure in its position.”
Two more transfer trailer side-roll tarping options are available from Shur-Co. Eighteen-ounce vinyl, combination 18-ounce vinyl and mesh, or mesh tarp material options are available for both systems.
The manufacturer’s premium belt and ratchet (PBR) fastens down with belts or cables on the side of the trailer. Belts attached to the tarp tube and ratchets located on the side of the trailer put tension on the tarp. A rope in the center is used to pull the tarp to the closed position and a crank can be inserted into a square-key weldment to roll open the tarp.
Another product, the Shur-Lok, is equipped with a latch plate along the side of the trailer, under which the tarp rolls to hold the tarp tightly closed. The crank handle applies the necessary torque to keep the tarp tight and a 21-tooth spline U-joint and tarp tube weldment is used to tighten the tarp under the latch plate. A standard flex crank stays attached to the tarp tube and is stored along the side of the trailer, allowing the operator full access to the rear gate or doors without the need to climb on top of the trailer. Several front return options and an optional rear return are available.