A trailer that's right for one hauler may be wrong for another. To narrow the choices, a buyer must consider cost, warranty, gross vehicle weight (GVW) limits and durability. The type of system that will be used to dump the trash - a tipper at the landfill or a built-in mechanism such as a live floor or pusher - also should be considered.
Dan Adrian, president of AWT Transfer Services, St. Paris, Ohio, says it was easy deciding which trailers to purchase because the company knew its needs.
"We knew what our tonnage [per day] was, how long a distance we had to go and how many trips we had to make," he says.
AWT switched from steel transfer trailers to aluminum in 1982, and now has 30 aluminum top-loaded models. Aluminum trailers are lighter than steel, enabling them to carry more trash without exceeding GVW limits. This factor, along with quality workmanship, were key factors in the company's purchasing decision, Adrian says.
"We basically bought the lightest trailer we could find," he says.
Specialty Transportation Services Inc. (STS), Portage, Ind., hauls garbage in several states, so the company must consider each state's road weight limits and the garbage density when deciding the length, width and capacity of its trailers, says Gary Goldberg, president.
For example, Oregon and Nevada have higher road weight limits than other states, so the company can purchase larger trailers with greater cubic yard capacities to haul there, he says. Garbage in New York and New Jersey tends to be denser and wetter than trash in the Carolinas, so the company must purchase shorter, narrower trailers to haul it because the trash is heavier and takes up less space, Goldberg adds.
Goldberg also prefers aluminum trailers because their lighter weight means they can haul heavier loads than metal trailers, yet they still are durable. "The construction is better than it ever was, and the aluminum itself is very strong," Goldberg says.
The company has 750 aluminum trailers - 500 tipper trailers and 250 with moving floor systems.
Dave Nyblom, solid waste procurement supervisor for the King County
Solid Waste Division, Seattle, says to meet state road weight limits, the hauling capacity for the county's aluminum trailers is 26 tons, while the limit for steel trailers is 23 tons. The county keeps trailers for about five years before replacing them.
Mark Carroccee, vice president of R&J Trucking Inc., Youngstown, Ohio, says buyers must spec suspension, top and bottom rails, and cross members thoroughly.
The company specs 48-foot long, 102-inch wide live floor trailers, and 51-foot long, 102-inch wide tipper trailers. The standard width is 96 inches, he says. A good maintenance shop with a welder on hand is crucial for keeping up with repairs, he adds.
Mr. Bult's Inc., Burnham, Ill., has 400 top-loaded aluminum trailers and 15 rear-loaded aluminum trailers with compactor units. Tony Schmidt, general manager, says the main factors the company considers when purchasing the equipment are price, weight, longevity and maintenance costs.
John Ray, maintenance manager at Englewood Disposal Co. Inc., Venice, Fla., a division of Waste Management Inc., Houston, says durability, not price, was the most important factor when the company bought its five aluminum transfer trailers.
Ray says he looks for trailers that can last a long time with periodic maintenance and repairs. One of the company's trailers has been on the road since 1981. He also looks for a warranty of at least one year.
"We are a small privately owned company," he says. "When we buy something, we have to make sure it lasts."
Englewood started with smaller trailers but upgraded to larger ones when its garbage volume increased.
Down in the Dumps Deciding on a disposal mechanism is another step in selecting a transfer trailer. There are two options: Trailers designed to back onto tippers that dump the trash or trailers with built-in disposal mechanisms such as moving floors or pushers.
"It all depends on the individual job," says R&J Trucking's Carroccee, whose company dumps garbage at 20 landfills with a combination of 60 live-floor and 60 tipper trailers.
Using a moving-floor makes sense if the hauler dumps smaller loads or will use the trailer to haul garbage to more than one landfill, Carroccee says. The live floor trailers are more versatile in the sense that they can dispose trash at virtually any facility, but the tipper trailer must go to a facility where the hauler owns or rents a tipper.
"People use live floors for flexibility," he says. "But it really depends on the actual site you're involved with, and if you've got a pretty high volume waste stream dedicated to one landfill."
Goldberg says STS buys a tipper if the company has at least 15 trailers hauling to a disposal facility. Some facilities rent tippers to haulers.
"Wherever possible, we try to put a tipper at the landfill," he says. "Each of them - tippers and live floors - has its own place in the industry. "
Many haulers retrofit trailers with live floors instead of purchasing new trailers. Live floor systems add approximately 2,000 pounds and increase the trailer's cost.
The King County Solid Waste Division uses live floor trailers exclusively, about 140 of them. Seven of its transfer stations have top-loaded steel trailers with moving floor systems, while one transfer station now uses rear-loaded aluminum trailers with compaction systems inside.
King County's Nyblom noted a difference in the tire replacement between the two unloading types - tipper trailers back onto smooth ramps, which does not wear the tires as fast, he says.
AWT's Adrian likes tippers' speedier disposal times. However, if there's a long line of trailers waiting to back up to a tipper, or if the tipper breaks down, the faster time vanishes.
Not Afterthoughts Finally, when purchasing trailers, don't forget the details.
For example, when the Montgomery County Solid Waste Services Department's, Dayton, Ohio, trailer tarps started coming loose, causing the trash to fall out, they had to make modifications, says Jack Gearing, solid waste manager.
But the problem has not completely been solved. "We're open to suggestions," Gearing says. "We want to see what other people are using."
The county initially purchased six rear-loaded trailers with hydraulic compactors and later bought 12 open-top aluminum trailers without compacting equipment to reduce maintenance costs. WA
A transfer trailer purchase should be based on well-defined hauling needs and well-informed trailer spec'ing.
The strength-to-weight balance is critical. A trailer should be strong enough to meet hauling demands, yet light enough to yield the greatest payload potential.
Hauling Needs To determine your hauling needs, consider the distance to the landfill; the number of tons moved per day; the weight per cubic yard of the refuse mix; and whether trailers are top-loaded or compactor loaded.
Two popular trailer types are the aluminum live floor transfer trailer and the tipping transfer trailer. The live floor transfer trailer has been the industry workhorse for awhile, but the lighter, tipping trailer has established a niche as well.
For either type, compare the trailers on the market, paying attention to the different grades of aluminum, metal thicknesses and the overall design and construction. The payoff is longer trailer life with less maintenance.
Strength-to-Weight Ratio To achieve the best strength-to-weight ratio, consider:
* Trailer Size and Design - To determine trailer capacity needs, use this formula: Legal payload capacity in tons/pounds per cubic yard of refuse = trailer capacity in cubic yards. For example, with a 25-ton legal payload (50,000 pounds) and a compaction ratio of 400 pounds per cubic yard, the operation would need a trailer capacity of 125 cubic yards. For better handling and a safer, more stable pull, spec a trailer with a low center of gravity. Also, payload potential and cubic yard capacity may increase with higher walls.
* Trailer Wall Thickness - Specify high yield aluminum within the industry standard range of H32-34 for greater metal strength. The H factor is the metal's hardness, with a higher number denoting a harder metal. A larger number of loads and heavy construction and demolition (C&D) waste may require thicker walls. Spec trailer walls between 51/432 inch and 11/44 inch. To withstand the rigors of compactor loading, side wall thickness should be a minimum of 11/44 inch. Additional horizontal bracing at the rear 8 feet to 10 feet of the trailer also is recommended.
* Floor Crossmember Depth - Overhead loading puts substantial stress on the crossmembers and bottom rail. The deeper the crossmember, the greater its resistance to bending-moment, and the stronger, more durable the floor substructure will be. Most range in depth from 4 inches to 511/44 inches.
* Top and Bottom Rail Extrusions - Top loading demands strong top rails to withstand hits by the loader bucket. Spec sturdy, reinforced top rails to prevent damage to the side walls and to reduce side bow. Rail size varies among manufacturers from 4 inches to 9 inches. The top of the rail should be at least 51/48-inch thick.The bottom rail extrusion should be as deep as possible to repel load shock. Most trailers have 4-inch deep bottom rails.
* Live Floor Slats - To better absorb load impact, haulers should spec a 311/42 inch wide slat with a 31/416 inch belly thickness and a double ridge design. C&D haulers can strengthen the 311/42-inch slats by upgrading to a slat with a 11/44-inch belly and 31/44-inch ridge height for extra support. For compactor-loaded trailers, spec'ing longer wear pads on a live floor of 6 feet to 10 feet, depending on the type of compactor, gives added protection.
The most effective trailer maintenance policy that waste management professionals can adopt for their operations is prevention. Routine inspection and basic preventative maintenance (PM) practices will help optimize trailer service life and productivity, limit expensive repairs and downtime, and increase trailer resale value. Below are PM practices generally applicable to all transfer trailer models.
General Trailer and Suspension:
* Lubricate all latches and grease points weekly.
* Check fifth wheel and king pin for cracks and unusual or excessive wear. Lubricate fifth wheel weekly.
* Inspect support legs, mounting plates and bracing for cracks. Use proper weld techniques to arrest cracking.
* Tighten loose fasteners and lubricate support legs.
* Visually inspect for excessive wear and cracks on all suspension components, including leaf springs and air springs. Replace air springs that have cuts or tears.
* Check all hoses for cracks, pinching and abnormal wear. Replace as needed.
* Check air pressure in tires following the manufacturer's recommendations.
* Check brake valves, linings and drums for unusual or excessive wear. Replace as needed.
Hydraulic and Floor System:
* Keep hydraulic reservoir full and hydraulic oil clean by filtering. Change filters per manufacturer's instructions.
* Check for loose fittings, cracked or chaffed hoses. Replace as necessary.
* Check couplers and hydraulic cylinders on the floor for leaks. Tighten or replace as necessary.
* Ensure floor slats are properly torqued to the cross drive and adjust floor-switching valve as needed.
* Check the double acting telescopic cylinder for leaks and scarring. If leaking, tighten or replace O-rings and packing as needed. Check for loose stage rings. Depending on scarring severity, replace or repolish the cylinder stage.
* Make sure blade is running true inside the trailer and not obstructed by any damaged side walls.
* Ensure wiping seals are in good condition. Replace if needed.
Also, consult with trailer manufacturers, who are a valuable information resource for advice on best maintenance practices for a specific situation.