Steel is stronger than aluminum, but it also is heavier. Consequently, to maximize payloads, aluminum is the metal of choice for many long-distance haulers. While steel trailers might be durable, aluminum trailers have come a long way.
"The manufacturers really have done a good job addressing some of the weak points of trailers," says Tom Wills, director of maintenance for Wills Trucking, Richfield, Ohio, a long-distance waste hauler operating 112 transfer trailers along the East Coast. "[Trash trailers] really started becoming popular in about 1987. Since that time, all the manufacturers have significantly improved the overall quality. All of our trailers are aluminum, and they last a lot longer than anyone expected."
"We try to get the maximum structural strength while keeping the weight of the trailer at a minimum," says Gary Goldberg, president of Specialty Transportation Services Inc. (STS), Portage, Ind., the nation's largest long-distance waste hauler. "We are constantly weighing maximum payload vs. structural strength, especially the strength of top rails, which receive a lot of abuse."
With stronger designs and longer distances traveled between transfer stations and regional landfills, aluminum trailers continue to be the workhorse in the long-distance hauling industry. Nevertheless, steel still has a place in the transfer station arena.
Distance Makes a Difference When distance isn't a factor, steel becomes a stronger choice, especially for the Palm Beach Solid Waste Authority, Palm Beach, Fla. The majority of the authority's 80 trailers are steel, which helps the trucks better withstand the rigors of top-loaded compaction, says Matt Chapman, the Authority's equipment maintenance supervisor.
Steel also is the choice for the city of Memphis, Tenn., which owns 12 steel trailers equipped with ejection systems. "You'd be surprised at how many ejection units still are out there," says Paul Patterson, Memphis' administrator of Solid Waste Operations, "but the trend is heading toward live trailers."
According to Patterson, Memphis has been using steel trailers since building its first transfer station in 1972. Of the three transfer stations operated by Memphis, two use steel trailers. The third and newest facility uses aluminum trailers with live floors.
This is because, like Palm Beach, distance isn't a factor for Memphis - all of the city's waste is taken to one of two nearby regional landfills. "We're blessed with relatively short distances to our disposal sites," Patterson says.
Steel trailers also are a common choice for long-distance construction and demolition waste. Silverole Trucking Inc., Rochester, N.Y., has 20 steel trailers in its fleet designated exclusively for demolition waste. Steel is good for demolition," he says. "It's a lot more durable, but you pay for it in weight."
Whether you choose steel or aluminum, live floors or tippers, most trailer manufacturers can accommodate the specific needs of any hauler. Quality has improved industry wide, and therefore, the lowest price prevails in most trailer purchases.
"We bid every time we purchase trailers because we're a government agency," Chapman says. "Usually, we go with the lowest bidder. Anybody can build a trailer to your specs these days."
But price isn't everything. Warranties and service also must be factored into any purchase. Memphis, for example, tends to buy from local vendors with good service records. "One of the things we consider when purchasing trailers is a vendor's ability to service trailers under warranty," Patterson says. "We need to know if we're going to get a reasonable response time on service."
Before purchasing new equipment, Patterson says city officials also make calls to sister cities for recommendations on equipment and vendors. It's common for a vendor to drop off a new trailer for Memphis to test for a month or two, Patterson adds. "We'll ask vendors to bring in a piece of equipment [so we can] run a test on it to see whether we like it and whether it works well with our applications," he says.
Unloading Choices In an ideal world, one type of trailer could be used at every transfer station, landfill or incinerator. But in today's solid waste environment, equipment is not always compatible, leaving many long-distance haulers trying to be all things to all facilities.
For example, some haulers may equip their trailers with live floors, especially if the trailers are not designated for one specific facility. This allows the hauler greater dumping and routing flexibility. For example, while one landfill in Pennsylvania might have a tipper, another in Georgia may not. Live floor trailers allow haulers the ability to take loads to any facility anytime.
"We use live floors when we're hauling out of transfer stations and going to different landfills," says Goldberg. Goldberg says this is especially true on the East Coast because, for example, there's a lot of volume coming out of New York and New Jersey, and it's not all going to one landfill.
"Many landfills have daily caps, so we'll take 200 tons to one landfill one day and another 200 to another. It changes daily," he says. "In these cases, we find it advantageous to have live floor trailers."
"We pretty much use all live floors [since] we deliver to several different landfills and burn facilities," adds Dean Desantos, president of Dart America, the Canfield, Ohio-based parent company of Dart Trucking, a hazardous and non-hazardous waste hauling company, and Dart Services, a waste brokering company.
Again, like steel vs. aluminum trainers, distance is the complementary factor to weight. While live floors add weight, for shorter routes such as in Palm Beach, where all the waste is collected at one of five in-county transfer stations and hauled to the in-county burner, payload isn't a big factor.
However, for long-distance haulers, maximizing payloads is perhaps the biggest concern. "What we've found through running proformas is you have to run it both ways - the distance from the transfer station to the landfill and the number of loads per day vs. the capital expenditure of investing in a tipper," says Wills. "I don't know what the break-even point is."
But the cost factor is a moot point if a landfill doesn't operate a tipper, Wills adds. Wills Trucking has considered tippers on some larger contracts, but the company currently does not operate them.
On the other hand, STS currently operates 22 tippers at landfills across the country, and 700 of its 1,250 trailers are tipper ready. "When we know the municipal solid waste (MSW) is going to go from a transfer station to a designated landfill, we'll put a tipper [there]," Goldberg says. "First of all, it has to be for long-term, high-volume contracts."
T&J Trucking, a Boardman, Ohio-based long-distance hauler servicing several markets east of the Mississippi River, also operates tippers. "We have our own tippers, or we have operator contracts with third parties that aren't associated with the landfill," says Mark Carroccee vice president.
Trailer maintenance costs are another factor. Garbage generally is not forgiving to trailers: Compactors crush; MSW is not all soft kitchen trash; side walls get scraped; brakes get worn; and lights burn out and need replacing.
Desantos says Dart America conducts monthly visual inspections to check the tires, lights and bushings, as well as to adjust the brakes. Every six months, the hydraulic drive unit of the floor, the floor itself and the bearings that support the floor are checked for wear.
"What history has shown us is that we have to rebuild the drive unit and replace the bearings in the floor ... [based on] ... how many loads you off-load," he says.
"We off-load an average of four loads per trailer per day. Longer haulers with less off-loads might not have to replace their floors as often."
To maximize the life of its live floors, Silvarole Trucking, rotates them every two to three years as part of scheduled maintenance to promote even wear.
"Normally the back of the floor wears out before the front does," explains Neil Silvarole, company president. "We'll pull out the floor and turn it around. There's no set schedule. We go by looks."
Every time Silvarole Trucking rotates a floor, all 990 plastic bushings are replaced, which, according to Silvarole, is less expensive than replacing worn-out slates with new ones. And, he admits his trailers probably get used more than most, which increases the frequency of his floor rotation schedule compared to other hauling companies.
"It's kind of like rotating and changing tires on your car," he says. "Where a taxi might need a new set of tires every three months, the average guy only buys tires every three years or so."
The Best of All Transfer Station Worlds Overall, most haulers are satisfied with the quality of today's transfer trailers. But they'd like to see more cooperation among transfer station and landfill personnel. In some cases, lines are getting longer at many regional landfills because haulers will cross state lines for cheaper, available airspace. But for a hauler, time is money, so efficiently getting trailers in and out of transfer stations and landfills is crucial.
"It's getting to be a nightmare for the truckers waiting in line at large landfills," says Carroccee. "A trucker's time should be spent on the road, not waiting at the landfill."
To shorten the turnaround times at larger landfills, Carroccee recommends multiple dumping faces and better scale traffic management. Landfill roads also can be improved, he says.
For example, large tractor trailers are a relatively new phenomenon at landfills, and many have not made the adjustment to accommodate the requirements of the big rigs. While a rearloader may be able to navigate through the muddy roads leading up to a landfill's working face, long trailers brimming with compacted loads are prone to getting stuck.
Transfer station operations also need improvement. Goldberg sees a trend toward contracting the loading operations at transfer stations. STS prefers to load its own trailers to ensure maximum payloads and protect its equipment. "We take better care of our equipment," Goldberg explains.
Additionally, turnaround time at transfer stations could be quicker. According to Patterson, Memphis is considering investing in yard tractors for trailer spotting. Currently, the city's tractors both haul and trailer spot. According to Patterson, a yard tractor could maximize empty trailers by pre-loading them instead of waiting for a tractor to return from the landfill.
Improving transfer station design ergonomics also is a necessity. Poor design can lead to trailer damage from day-to-day. "Transfer station design is one of my pet peeves," Silverole says. "Engineers never make the doors wide enough so that they are level with the tipping floor walls. A lot of trailer sides are wrecked because of it." He says door openings should be flush with the tipping floor walls.
Overall, improving transfer station efficiencies is all about time, distance and maximizing payloads. The equipment is available to properly get the job done. As with other industries, efficiency still comes down to the people operating the equipment.