Tarps and Rolloffs: Building for Safety and Profitability
Whether a contractor or a municipal operation, today's solid waste haulers want safer and faster trips to the landfill.
When it comes to commercial waste collection and transporting, the emphasis for the past few years has been on ways of boosting production - of getting more waste to the landfill - yet reducing the operator's chance of an injury. This has become even more of an issue as more and more states have passed mandatory tarp laws. To stay legal, more and more drivers have had to climb on loads, even under inhospitable weather conditions. Fortunately, tarp and container manufacturers have answered that need by providing both automated and hand-tarping strategies as well as ways of shortening the cycle time whether loading or unloading.
A Major Participant Talks
|The Hy-Tower SL raises 15ft. above the truck frame.|
Pioneer Cover-All Inc. in North Oxford, MA, has been supplying tarps for 40 years, introducing its first automatic tarping system in 1967. Says Lenny Brescia, vice president of sales, "Our first system was designed for the aggregate industry. It was rudimentary and flimsy by today's standards. The early systems were not always easy to operate either. Our quest became - and is still today - to upgrade and design new systems to improve safety features and user-productivity. Through the years, we have received international and domestic patents; the most important of which are for refuse industry systems. Pioneer has a patent for telescopic arms and, more recently, for the rights to a rack-and-pinion system that prevents freefall of the pivot arms."
The telescopic arm is ideal for operators who must haul different-length containers on the same bed. The pivot arms remain "locked in" as the arms traverse the load, avoiding the problems of gravity as the tarp covers or uncovers beyond the 12 o'clock position. Brescia adds, "The Rack'n Pinion covers or uncovers in eight seconds. We designed it so the operator can stand on the ground, outside the cab, and watch the tarp. He wants to make sure it's free of branches or electric lines."
He adds, "Our tarping systems have come a long way. Operator safety and efficiency, ease of use and maintenance, durability, and quality of the units - all these advances make tarping a load much easier and better than it was years ago." Brescia acknowledges that the tarp itself is still the weakest link in the chain. "Through the years, the tarp fabrics have also been improved and made to be more durable. Advances in fabric technology have not been a magic bullet. The tarp is still a wear item, subject to the weather and load conditions. They can and will tear. User care is still the most important element in the life of the tarp or the system."
Containing the Load
"When the trend changed from hand to mechanical tarping, it was for profitability," explains Woody O'Brian, president of O'Brian Tarping Systems in Wilson, NC. "Automated tarping systems make possible an extra trip per operator per day, so more profit for the company. Then solid waste operators saw it really was more of a safety issue because there were fewer drivers slipping or falling and injuring ankles and hips.
"With a mechanical tarping system, the driver can cover a load in 20 to 45 seconds, with 30 seconds as a good rule of thumb for speed without endangering the tarp."
When asked what an end user should look for in a tarping system, O'Brian continues, "As with any equipment, the driver needs time to get oriented, but we've found the joystick approach more driver-friendly. After three to four trips he should have it down pat, although seven trips to the landfill is an industry average. But when the driver's comfortable with the system, he can focus on pickup and delivery.
"You need to keep the vehicle on the road and out on the job, so look for a durable product with limited maintenance. We also feel the new option of in-cab controls is ideal with hook-lift systems. The driver backs to the container, pulls it on the hoist, and covers the container without leaving the cab. This saves time and therefore increases the bottom line.
"We've also learned that if the tarp is on a roller mounted on the arms instead of stationary behind the cab, it will last about four times longer as a result of [it] rolling out over the load instead of being dragged across it."
Avoiding Load Traps
Now and then, if an operator is not careful, the tarp can be trapped by a shift in the load. Cindy Cook is marketing manager for Roll-Rite Corporation in Alger, MI. She says the company's device, which is electric over hydraulic and powered by self-braking gear motors, can avoid manual tarping traps because, when mounted on an adjustable tower, it can be raised higher than the top of the load. "The self-brake feature prevents the operator from accidentally releasing or reversing the tarp.
"Thanks to hardened aluminum alloy, system components weigh up to 40% less than comparable steel systems. Plus, aluminum is more forgiving when stress is involved." She also notes that if an existing vehicle has at least 12 in. between the cab and the box, there's room to retrofit an automatic tarping system. Tarp lengths need to be 4 ft. longer than the longest box the vehicle is likely to haul. This is to keep the tarp on the spool while still covering the distance between the tower and the box.
New in Roll-Rite's pivot lineup is a sliding lay-down pivot straight arm, which mounts between the container and fender or above the tires on fenders. "We recommend the newer pivot because of pending federal DOT [Department of Transportation] issues with keeping [the] outside width of safety equipment within 108 inches. This pivot, once installed at that width, can still clear a 102-inch box with room to spare."
Again, whether to go with hydraulic arms or mechanical arms is a matter of preference. Cook comments, "Although automated systems are faster and safer, companies are hesitant about arm systems. A real concern is cost, especially maintenance or repair. Occasional loading problems can cause a container to damage arms. Replacing a cylinder-free mechanical arm will cost about $75. A hydraulic one could reach up to $1,800, not including longer downtime and hazardous-waste disposal from arms leaking fluid."
The same can be said about hand tarping for a small operation versus taking on an automatic system. Mike Sanchez, vice president of sales and marketing for PacTec Inc. of Clinton, LA, points out that it is an experienced player in the industry. "We have over 13 years of experience, 55 employees, and 50,000 square feet of warehouse and manufacturing space. We use 1.5 inches of webbing around every tarp and a machine-set brass grommet." He adds that about 60% of the company's solid waste end users are still hand strapping with bungee cords. "These work especially well where the tarp stays with the box. In that case, the operator can keep one side tied, and all he has to do is work out a way to throw the tarp off to that side so he can remove the load.
"About 90% of the smaller waste operators are using lay-flat throw tarps, which need just five cords per side. If the operator has to spread a new tarp, it will take about 20 minutes. If he has bungees already attached, he can cut that time in half."
Another strategy is for operators to use fitted front-end tarps. "Then the driver can start pulling down the tarp, and the wind doesn't have a chance to blow it off or tear it up. Yes, hand tarps still need some climbing, but not to the extent of just a few years ago. A given load can be uneven because it's filled with different types of objects. That's why the larger operators prefer auto tarping but smaller operators are still asking for help with manual tarping."
Keeping It Clean
Cleanliness is ever a challenge in the solid waste business, and that goes for internal cleanliness as well. Delton Garnett, vice president of G&H Manufacturing Inc. in Arlington, TX, reports that his company has found a solution. "We're using a 1-micron filter to clean hydraulic fluids in our hydraulic systems. We have a laser particle counter to test [ISO certify] every truck before it leaves the factory. The oil in the hydraulic system is cleaner than that used in auto oil. Our warranties are five years on cylinders and three years on hydraulic components." Furthermore, users can wait a minimum of one full year before changing the hydraulic fluid in the rolloff body.
Garnett states, "We're trying to build a rolloff body that will last years and years. We're also filtering the hydraulics in the tarping systems we install. Pioneer's rack-and-pinion tarper is on 95% of the vehicles getting a tarping system."
Other recent developments at the company include reducing the cycle time of hydraulics by one-third, which gives operators a chance for greater productivity. "Industry standard for 7-inch cylinders is 60 seconds; ours is 39 seconds, with 34 seconds for 6-inch and 62 seconds for telescopic cylinders instead of 96 seconds. We're also installing steel tubing, with zinc-cobalt plating, which is rated to withstand 1,000 hours of salt spray before we introduced it to the market. The steel is extruded so there's no seam to crack or leak. The JIC and SAE fittings used throughout the system help eliminate leaks."
He states that 90% of road calls, and the resulting hauling delays, are for blown hoses. "By going to plated steel tubing in place of hoses, you eliminate a lot of road calls." Further changes regarding safety include a proximity hoist-up alarm that's more difficult to defeat and aluminum bronze bushings on all sheaves, which are designed to last four times longer than bronze alone.
But what does the nation's largest rolloff-body and trailer manufacturer have planned for 2003? "We're introducing a patented pneumatic box lock for rolloffs that operates off the PTO [power take-off] switch. The driver will be able to lock down boxes without having to get out of the cab and will know the box is locked in place before he heads for his destination."
Hoists for Every Axle
|The Hooker: If one cross-member interferes, the other hold-on engages.|
In Winamac, IN, Galfab Inc. manufactures cable rolloff hoists for single, tandem, tri-, and quad-axles. "Everybody in the industry needs hoists; we try to accommodate them," reports Perry Frakes, inside sales manager. He too sees the development of automatic hold-down systems for hoists as one of the more significant developments in the past few years. "There's no manual chaining or nylon strapping. Once it's loaded, the driver may not have to get out of the truck. As soon as the box is on and down and the driver shuts off the PTO, the container is ready for transport.
"Most hoists have a hold-down on the hoist and a stop on the container, so the two come together. The problem was each container manufacturer had its own design and location for the stop on a container, so not all were compatible with the hoist. A lot of those hold-downs were cut off by end users because they didn't interface. Then when they'd go around a curve, the load could shift, leaving the container to possibly roll off sideways."
The second-generation hold-down requires an operator to mechanically secure the container with a chain binder or a cable or nylon-strap ratchet, which can take as long as 10-15 minutes, hence the temptation to forego the tie-down. "In 2001 we introduced The Hooker, our automatic hold-down system, which is attached to the rolloff hoist. The Hooker works on containers that have 6-inch-long sills and 3-inch cross-members. Operational controls are installed with PTO controls - [that is,] when the PTO is engaged, hold-on arms are unlatched, and when the PTO is disengaged, hold-on arms are in a latched position." While six hours of yard time is needed to install the device, ongoing maintenance is minimal.
What could be done to improve the container design? "Rolloff containers are so standard," Frakes notes. "Basically they're a big metal box that you throw garbage in; everybody builds them about the same. What varies from one manufacturer to another are the hinges and latches." Regarding tarping loads, he comments, "There's a whole industry for tarping loads, whether mechanically or manually. If you don't tarp light material, it can blow out, and a lot of DOTs require solid waste haulers to tarp the load."
Tarps for All Uses
|A hook-lift hoist working with two different types of bodies: a 20-ft. shipping contaner (above) and a typical waste container (below)|
While the solid waste industry is a strong user of tarps for transportation, there are a number of other industries out there that also use tarps. A longtime tarping supplier is Shur-Co, a family-owned business headquartered in Yankton, SD, celebrating its 50th year. It is the producer of the original Shur-Lok Roll Tarp system. It's a side-roll system originally designed for the ag market, but expanded to meet the needs of construction, flatbeds, metal fabrication products, and of course solid waste.
Bob Jenks, a unit business manager for the company, reports that the system can cover a solid waste load in 20 seconds. "We have a number of tarping systems, with two designed for solid waste. One is our original Shur-Lok system, while the other is a premium belt-and-ratchet system. We've been producing both for the waste industry for the past decade. We are using primarily a vinyl-coated domestic fabric material that's waterproof. Where rain is not a concern, we also supply a mesh fabric, which secures the load and saves money."
When Lifting the Box
Metro-area operators usually find that hauling waste to the landfill keeps their vehicles busy. But at the other end of the spectrum are those in more rural areas where it's not only farther to the landfill, but there also might not be work enough to keep a full schedule. "Operators need to be able to use the same truck as a dump truck, a flatbed, or a material hauler," comments Jim Jorgensen, regional sales manager for SwapLoader U.S.A. Ltd. in Des Moines, IA, a leading manufacturer of hook-lift hoists. "Several of our customers have started out with a SwapLoader hoist to transport construction debris and waste from their own operations. Then they've seen the opportunity to take the hook-lift hoist and contract out to haul other loads for other contractors, material haulers, et cetera, which keeps their vehicle on the road and busy all the time."
He says a municipality in the Boston, MA, area saw a need for a hoist in its waste collection. "They soon discovered by utilizing the truck and hoist more fully [that] they could expand the use into the fire department, where the hoist could transport different vehicle bodies out for fast response to a fire or accident scene, including a flatbed set up to fight brush fires, a van designed for dealing with hazardous-waste spills, and another one outfitted with a portable generator and light bar for nighttime response. Yet they were still able to use the hoist in waste collection as originally planned.
"The key to today's marketplace is to be able to utilize all of your assets to the optimum. No longer can today's waste hauler focus on just one segment of the business. He has to find a way to be more to his customer than a waste hauler. He needs to find two-way transporting versus one-way trips to the landfill."
But what's a buyer to look for in a rolloff hoist? Replies Jorgensen, "Safety, comfort, and convenience. Does the body or container stay in body locks when you go in the dump position? If not, when raised in the dump mode it has the potential to fall off the truck, putting anybody on the ground at risk. Look for systems designed with strength in mind. You want a hoist that has gone through a rigorous testing program before production."
In addition, make sure the hoist's hydraulic system is compatible with other hydraulic uses of the truck. "Ours are designed around a low-pressure, high-volume hydraulic system enabling the user to expand the system to meet those needs. For example, we find many users will expand their hoist from hauling waste and construction debris to being able to install a salt sander for ice control or dump bodies for hauling away dirty gravel, and it's all done with one truck."
More Things to Consider
Another major hook-lift hoist provider is Stellar Industries Inc. in Garner, IA. Glenn Rasmus, hook-lift sales manager, comments, "Basically waste collection has two different markets: the long box and the short box. The long box is anything over 18 feet, with the short box typically a 10-foot box. But for either market, the hook-lift system is able to pull more containers on a daily basis than with a cable system." He gives the case of a $12 million sewer project in western Oregon involving just four tractors but also 20 14-ft. dump bodies being hauled to a landfill 1.5 mi. away. Cycle-time speed was of the essence because the digging crew had to stop if a dump box wasn't there.
"They did a minimum of 33 pulls a day and sometimes as high as 42. Onsite time for each driver was 30 to 45 seconds, and that included having the crane operator handling the boxes pull off the empty box and place the full one. Part of the speed came because the crane operator had only 42 inches of travel to lift up the truck so the driver could back under and secure the load." An onsite traffic manager helped ensure that each load was properly fastened.
Rasmus gives these five points on what a user should keep in mind when buying a hook-lift system:
- What kind of business is the hook going to be used for?
- How much weight does the hook have to pick up, including the weight of the container or flatbed?
- If you're dumping materials, what is the shortest and longest body that has to be dumped?
- If a flatbed is going to be used, what is the longest body to be used? Also, what is the height of the equipment you intend to haul?
- Consider chassis info, such as wheelbase, frame resisting bending moment, axle capacities, transmission type for PTO, and whether its a cab-over or conventional.
Rasmus is a believer in tarping systems. "Tarping systems help prevent workers' comp claims and downtime. For a long body, automatic tarping can save a minimum of five minutes - and that's in good weather." As a supplier, Rasmus reports that tarping systems are simpler than ever before and that the tarps themselves are being made out of better materials, so they're lasting longer.
Bill Garrison, vice president of sales and marketing for Clement Industries Inc. in Minden, LA, has been in the solid waste industry since 1970. "The major thrust has been in the reduction of man-hours to do the same job, and at the same time the reduction in exposure of the workers to on-the-job injuries. I think that's the most amazing part of the solid waste industry. For example, back then a typical rearloader garbage truck would have a crew of three to four and a driver. Today it's rare [that] there are three on the ground."
Looking at today's challenges, especially with dump trailers, he comments, "Whether it's rolloff or conventional dump, the problem with the box is the leveling of the load as you go. You need to do anything you can to equalize the load on all the vehicles' axles." That's where he reports Clement's patented sliding tandem axle comes into play. "Going down the highway you have the tandem slid to the back end. You get to the landfill, pull the tandem forward, and you can dump it more easily."
Garrett adds that some of the company's more recent work has been to further reduce trailer net weight. "We took a trailer that weighed 12,300 [pounds], and a new trailer with the same dimensions, same thickness, and [same] types of steel is 1,500 pounds lighter. Aluminum has been around forever, but alloys have been gradually improved to the point where an aluminum trailer is a strong structure yet still 15% to 20% lighter than steel." But there's still stainless - which doesn't need the plastic liner yet is impervious to fly ash - which he sees as a growing market.
The term Dumpster was invented back in 1933 by Dempster Equipment, originators of the rolloff container industry. Unfortunately, over the years the firm lost quite a bit of market share - until new management and its associates, taken on in late 2001, posted a dramatic 40% sales boost during 2002. "We're gaining ground," declares Rich Mullinax, director of sales and marketing. "While many people want lighter boxes for lighter net loads, we're finding that [others], especially in the metals industries, want the same sturdy box we've been making for decades."
Mike Anderson, director of engineering, reports that a California customer has worn out three chassis for the Dempster Dinosaur he bought in the '60s, while US Steel in Gary, IN, is dumping fly ash into the container at a temperature hot enough to fry the paint from a new box.
That California customer, DBW Metals Recycling of Anaheim, hauls three to four loads of metal a day to customers within a 50-mi. radius. "We have 75 rolloff boxes ranging from 18 to 24 feet," reports Stewart Shirk, general manager, who has been with DBW for 27 years. "The unit was here when I came, and it's now on its third chassis. It's similar to the DSU 60 that Dempster sells, with two tilting arms. We hand tarp for aluminum cans, painted aluminum, and when we take our own paper and cardboard to the recyclers. Our driver, Larry Jemison, has been here over 20 years and tarps what he knows would make a mess, and we've not had any problems with debris on the highway."
What About Lids?
While tarps have been the cover of choice for hauling municipal waste, Impact Plastics in Carpentersville, IL, plans to introduce a plastic lid during summer 2003. Scott Lemajeur, president for the firm, points out that the company's focus has been on plastic lids for front- and rear-loading Dumpsters. "This new lid will be 4 feet by 8 feet, so the typical rolloff would require four or five lids to completely cover the box. They can be hinged or attached by the rolloff manufacturer."
Although the product was under development at the time of this interview, Lemajeur reports the new lids will be as temperature-hardy as their collection predecessors, so neither sagging nor cracking will be a problem. He adds that the operator will be able to close and secure the lids from the ground, eliminating the need to climb on the box.
Plastics in Rolloffs
Another believer in plastic for a tough industry is Bucks Manufacturing Inc. in Hadley, PA. Dennis Weaver, sales manager, reports that plastic is ideal where there are sticky or corrosive loads. "Poly releases easier than steel, plus it has a higher tolerance to acids, heavy salt, oils, and other chemicals, but it's not designed for [construction and demolition] applications." Instead its niche is in food processing, wineries, dough, animal rendering, and even coke-oven condensate.
He adds that cold weather is not a problem. "We had a completely frozen load at 15° [Fahrenheit] that slid right out when the load was tilted."
Regarding tarping systems or manual tarps for his rolloffs, Weaver reports, "Our customers use hand tarps and side-roll tarp systems, both of which we supply, and they also use automatic tarping systems that are mounted behind their cabs. Those we do not supply. Automatic tarpers are a very common and popular method for our customers because they can be operated from inside the cab. This lends to more efficient hauling. Over the course of a week, month, or year, this can dramatically add to the hauler's bottom line."
Author's Bio: Journalist Joseph Lynn Tilton specializes in land and building issues.