Janury-February 2001

Transfer Trailers Keep the Wastestreams From Flooding Communities

The ongoing metropolization of America, along with the burgeoning of federal regulations, presents a growing challenge for those charged with the safe and affordable disposal of solid waste. Not only are landfills getting full - introducing the challenge of replacement - but the cost of diverting waste can play hob with a private company’s bottom line or a community's operating budget. Fortunately, transfer trailers offer some interesting options for municipal and private waste-collection operators to consider.

In the private sector, one of the larger participants in waste hauling is Republic Services, which operates in more than 300 marketplaces in 22 states. Smaller sites will have two to three trailers transferring 40-50 tpd, while others will utilize more than 100 trailers. Some are gathering waste within a 20-mi. radius, while others get waste from 200 mi. away.

Naturally, this company has a variety of transfer trailers, including tippers, live floors, and even possum bellies. Speaking from his Fort Lauderdale, FL, office, Mark Clinker, Republic's director of landfill and transfer operations, emphasizes, "The marketplace determines what type of equipment we use. Our smaller facilities handling smaller tonnage typically need a very economical way to transfer waste, so they tend to use a common trailer that doesn't require a lot of maintenance. For them, a tipper trailer works well."

Clinker points out that Republic utilizes both internal and external transfer trucking operations to move waste from transfer stations to the landfill. "If a local manager has a lot of savvy, he'll run it himself, but there are cases when we use third-party haulers because they can be more economical than maintaining our own fleet."

He reports that there are instances when, as a landfill operator, they provide a tipper so haulers can use either live-floor or tipper trailers. "A live-floor trailer generally requires a little more maintenance than a straight tipper, but a live-floor trailer can be used at any facility. Tippers require lower maintenance and can haul increased tonnage, but there is no flexibility. Once loaded, the only way to get the waste out is to tip the trailer. It takes only about four minutes to tip a trailer versus 12 to 15 minutes to unload a live floor.

"Another concern is the safety of the employee who has to climb up and physically place a tarp over the load," Clinker observes. This is where catwalks and automatic tarps are useful.

A particular challenge for this major player is that when it acquires a company, it sometimes inherits the fleet of transfer trailers, which can include all brands and all varieties of trailers. Part of the work is bringing an acquired operation up to speed. Clinker continues, "We've had some facilities build catwalks to go around the trailer to assist in tarping loads. A catwalk is a good addition to the operation and does not add weight to the trailer."

A decade ago, flatbeds were popular, but use has been declining. "Flatbeds are used successfully in some markets. For example, some transfer stations in New York City bale waste and ship it out of the city using flatbed trailers. Outside haulers delivering steel from Pittsburgh will back-haul those bales to a landfill in western Pennsylvania, about 200 miles from the transfer station."

Clinker emphasizes, "Flexibility is the key to success. The bottom line is that you must know your market and select the equipment that will best serve your specific application."

Flexibility Also Helps Smaller Player Win

Ted Carter, founder of ABC Disposal in Cedar Rapids, IA, has just four transfer trailers, but those trailers have made it possible for his frontloader and rearloader route trucks to unload without the need of an actual transfer station. "A transfer station can cost $2 million," Carter explains. "That's why we're using Wilkens X Series expandable trailers with live floors. We have the trailers at an old farm site that the city grew up around, and our route trucks can easily back up the ramp and into the trailer. We have no trouble getting a 40,000-pound payload for our drive to the Quad Cities area 100 miles away."

Carter adds that the trailers deadhead rather than back-haul. "We thought about back-hauling because there'’s a lot of barge traffic. But we just don't have time to do back-hauls. On short hauls, you can't make any money unless you own the load. Besides, you'’re limited on what you can back-haul unless you take extra time do a thorough washdown after dumping the waste." Then there's the matter of waiting for the load.

How did he get into the idea of drive-on transfer trailers? Carter explains that as a private refuse-hauling company picking up its own trash from retail and commercial customers, the need is finding a landfill with more affordable dumping rates. Cedar Rapids will soon be closing one of its two sites. The second one has just six years of space left, and disposal rates are high.

Fortunately, that part of Iowa doesn’t have severe weather conditions, so a longer haul is feasible year-round. "Some of the winters get tough, with ice and snow and down to 20-below [Fahrenheit] on occasion. Our Keith live floor of aluminum slats will freeze occasionally, but we’re able to get them broken loose."

Carter says he saw his first on-loading transfer trailer at a demo in Chicago four years ago. He found it user-friendly, so he bought the demo. He got the two-year-old trailer as a reconditioned unit. "Newer units will cost $70,000 to $100,000," he notes, "so the payback period for me is about three years. But they last and take very little maintenance. Other than the live floor, the demo looks about as good as the day we bought it."

Another advantage is that the setup is easier on route vehicle tires than during landfill visits. "As you know, flats are a problem when a truck has to use a landfill. I asked one of my frontloader drivers how many flats a week he gets. The driver told me that since he's been loading into the transfer trailer, he hasn't had a flat with the last three sets of tires."

Orange County Reveals Trailer Strategy

Mike Beebe, utilities supervisor for Orange County, FL, reports that the county uses 100 transfer trailers and is changing its specs. "We used to have ram pushouts, but the trailers are just too heavy. We now have 38 live-floor trailers, and each saves us 7,000 pounds of dead weight versus the ram pushouts. This year, we bought seven aluminum live-floor trailers, and that saves another 5,000 pounds in weight."

Beebe says the two transfer stations are about 25 mi. from the landfill, and trailers on a 10-hour day will make three trips a day or 900 mi. a week in a six-day workweek. When asked about durability with aluminum, he replied, "We went with heavier aluminum rather than the standard weights. We've been keeping the steel trailers for 10 years, but I'm hoping that we’ll get 12 to 13 years out of these aluminum ones. Humidity down here rusts out steel. By the end of 10 years, the trailers need to be repainted, cleaned, and even sandblasted. We’re in the public eye, so our trailers need to be presentable."

He adds that nine-leaf Rayco suspension has kept suspension problems to a minimum. "We also use duals to minimize downtime and road calls. Four years ago we went to the Keith walking-floor system and have not had a breakdown since."

Scheduled maintenance is key. Every 120 days, shop mechanics check the suspension, the fifth-wheel pin, all the lights, and the tarp covering system; lube the back door; adjust the brakes; and check the linings to ensure that the brakes are still sound. "Once a year we torque the live-floor slats and check all the bolts to make sure they're properly torqued and not coming loose," Beebe explains.

"Checking the tarp system is the big thing," he adds. "That’s how we avoid litter blowout - and tickets. And for the tarps covering our ram trailers, we have gone from hydraulic flippers that flipped from side to side to a roll-top Sherlock. This has really reduced our downtime for tarp repairs. We used to have to repair tarps almost weekly. With the roll system, we've had tarps go four years before we’ve had to replace them. The tarp covers 100% of the trailer and doesn't let any papers fly out. Papers can slide out through the crack in a hydraulic flipper."

Orange County also has moved the trailer lights from underneath the deck to in the back door. "When the lights were at the bottom of the trailer, garbage would fall down on them during unloading. Changing the location keeps the lights cleaner and brighter, with fewer repairs because lights never touch any garbage liquids," notes Beebe.

Handling Construction and Demolition Waste

In the Atlanta metro area, Arrow Waste Inc. of Doraville, GA, keeps 15 transfer trailers busy hauling construction waste out of the area to a landfill 28 mi. away in Lithonia. "Each trailer makes five trips a day," reports owner Rip Thompson, "so they average 1,400 miles a week, not including Saturday, which has two to three runs on a half-day schedule. We’re loading with a wheel loader, and our aluminum trailers have live floors."

Thompson notes that the transfer station is relatively new to the operation. "We've been offering transfer services for just five months. We get a lot of homeowners bringing in project loads, but the backbone of our work is rolloff-type hauling companies and contractors who do their own hauling. We have scales where we load, and the biggest challenge is keeping up with the volume."

He says that in less than a half year, the station has accounted for $1 million of its $6 million in business in 2000. In terms of the benefits of Arrow Waste owning its own transfer station, Thompson states, "It opens another revenue source. Our initial benefits were the savings we got on dumping fees and the ability to pick and choose where to dump. Landfills are closing because they're full, and transfer stations are becoming more of a necessity in the Atlanta area. Having our own transfer station has helped us tremendously."

It's done so well that Arrow Waste plans to open a new site in two years. That 3-ac. site will handle 500 loads per day, with 70% of the volume coming from outside operations. Thompson estimates the $2 million investment will carry a six- to eight-year payback period. "We continue to pick up from construction sites and haul to our station when we're not busy. But when we're busy, we'll send our vehicles to the closest transfer station in the area."

Thompson's advice about others operating their own transfer station is this: "The main thing is to own a landfill. If you don't own a landfill, you have to be very efficient to make a profit. You also need to establish very good rates to encourage use from more distant points."

Contract Haul Specialist

In Bigler, PA, Kephart Trucking has 320 tipper and 60 live-floor trailers in the transfer fleet alone. "We're dealing with a dozen transfer stations in New York, New Jersey, and Connecticut," reports Jack Yingling, fleet manager. "Capacity and weight are the two biggest factors, with durability a close third because our trailers get approximately 100,000 miles a year each, with hauls varying from 50 to 300 miles one way."

For this reason, the company lightens its tractors as well as its trailers by using Cat C-12 engines, with aluminum wheels all the way around on the tractors. This saves 1,500 lb. per combination. "Our goal is to be legal yet carry a 50,000-pound payload, which we can do."

The lighter-weight wheel system includes a Meritor PSI tire inflation system so a punctured tire can be inflated until the vehicle gets to home base or a repair facility. This makes it possible to run single wheels rather than duals, another weight savings. "This system has cut our tire losses by a third, and any on-the-road repair takes three hours, so the inflation system is a significant time-saver too."

Yingling adds that with lighter weight, cross-member spacing on the floor is another critical factor, with members set 15 in. on center. This gives durability without adding a lot of weight, and his fleet runs Mack, East, and Trail King. "I've had success with all three."

Weight is why the company is leaning toward tipper trailers. "The tipper trailer is the future in my mind," he remarks. Still, there is room for the heavier walkers, thanks mostly to back-haul opportunities. "Also, some landfills don't have tippers, so you need live floors."

The fleet also uses single-leaf spring suspension for durability and simplicity, and all brakes are extended service brakes with Wabco antilock braking systems.

"We use side-by-side roll tarps so the driver can cover and uncover the trailer from a catwalk built onto the front of the trailer. It takes about 15 minutes to cover and tie down completely. Keeping a tarp on an empty trailer reduces fuel drag, giving us up to three-tenths of a mile per gallon extra mileage, another significant saving with a fleet this size," observes Yingling.

Trailer finish is bright aluminum, no paint. All signage is with decals that let viewers know who’s hauling the load. "You've got to keep your name out there," he points out.

When it comes to lights, Yingling prefers LED because of less maintenance, but theft can be a challenge. "Aftermarket price for LED lights is $60 versus $16 for regular ones, but they'll last 10 years if people don't steal them. Some manufacturers are now making guards that can be bolted on to protect the lights, and ours are all protected now."

Live Floors Only

Stockman Transfer in Glencoe, south central Minnesota, started operation in 1989 with two tractor-trailers and now has 45 live-floor transfer trailers and 24 drivers. "We transfer mainly municipal solid waste in a 250-mile radius, and our trailers average 100,000 to 120,000 miles a year," explains Rick Stockman, who partners with his brother Brad in the operation.

Stockman Transfer has half a dozen different brands of open-top trailers, which work well in this land where 100ºF summers play off -30ºF winters and where rain, ice, snow, and fog make driving prairie country a challenge. "When we unload we do not open the tarp. We leave it closed, unless it’s a harsh load with lots of metal toward the top. In cold weather, trying to roll up a tarp is like trying to roll up a sheet of plywood.

"We load over the top, but use live floors because we don’t have a tipper system available at any of the half-dozen landfills we'e dumping into. I prefer the Keith high-impact three-and-a-half-inch slats. I've run lighter floors, but the weight factor is not that much saved (when you consider) the faster wearout of a lighter floor."

Stockman also prefers air-ride suspension. "It's easier on the equipment and easier on the driver, and we do install air gauges to read the pressure. So when we're loading we can load them right to the maximum weight." This avoids the need for onsite scales yet helps ensure that loads meet federal limits. In addition, the driver can tell the loader operator whether to add more debris in front or in back. This gets the vehicle in and out of a transfer station in about 45 minutes.

Landfill visits usually take less than 30 minutes unless mud is a problem. "Then we make sure the landfill operator keeps his Cat away from the rear door's hinge area when he's pushing us out of the mud. Once a driver is back on a hard surface, he makes sure the wheels are clean of mud before he takes off. Mud is tough on equipment."

100% Recyclable Hauler

Doug German, transportation specialist for NRG Energy Inc. of Newport, MN, says the company's 120 trailers are primarily live floor and are used to haul refuse-derived fuel (RDF) 45 mi. to the Redwing Steam Plant in Redwing, and 80 mi. to the Wilmart Steam Plant in Mankato.

"We, and a sister plant to the north, are contracted by seven area counties to process about 800,000 tons of waste a year, which outside haulers bring us. About 92% of what we receive is burnable, with 1,100 tons a month principally ferrous, which we deliver to a steel mill just down the street from us," he explains.

German prefers the Hallco live floor on his transfer trailers because that system has one check valve instead of six. "The Hallco poppet valve is proven to be more durable than others with the product we're hauling, which weighs about 7 pounds per cubic foot. We open the rear door, back up the trailer to the compactor, and can take on a 19-ton payload in 20 minutes."

Trucking is a round-the-clock operation, with each trailer averaging three trips per day for about 1,800 mi. per week. "We take in 1,500 tons a day on average and process nearly all of it that day. We can take an 8-yard bucket of waste; dump metal, plastic, grit, and rock in the pit; and take out the rest and shred it in three minutes." Both power plants can store as much as 800 tons of RDF. Thus, no matter what a Minnesota winter can bring in trucking delays, the plants continue producing power.

Dallas Eliminates Tippers

In Dallas, the city’s 24 transfer trailers are tippers. In fact, the city owns the tipper and the landfill, which is located about 17 mi. from its nearest transfer site. Nim Cash, fleet supervisor for the City of Dallas Solid Waste Division, emphasizes, "We've switched to self-ejector trailers. Our trailers haul six loads a day, sometimes as many as eight, but we were having to wait too long to get the prior loads of waste moved so our tipper could dump the next trailer. We couldn't double dump because the landfill's compactor couldn't handle two loads at once." Sometimes trailers spent an hour waiting their turn.

Nor could those trailers be tipped during a lightning storm or when winds hit 35 mph. "A tipped trailer becomes a lightning rod and can be blown over in a heavy wind. If our site were to have a fire, there would have been no other place close enough to haul to with the volume of material our trailers have to handle each day."

Cash, who has been with the city for 32 years, points out that the top-loading trailers can be loaded in 10 minutes, then it's 17 mi. of metro driving to the landfill. "The next site is another 7 miles away, and we can’t take the time to use it, so we've gone to live floors because they give us flexibility."

Whether large or small, private or public, transfer trailer fleets have found success by using the kind of trailer that best answers the challenges of their sites.

Author Joseph Lynn Tilton is a frequent contributor to MSW Management.