Automated Collection: The Next Generation
April 1, 1999
Lynn Merrill
If you're looking to streamline your collection system through automation, chances are you're in the market for high quality, durable equipment. Likewise, if you automated in the late 1980s or early 1990s when automation first took hold, chances are you're in the market for equipment, too. Why? Because equipment purchased in the past decade is deteriorating. Life expectancy for a cart is 10 years and trucks are lasting seven to nine.
The good news is that manufacturers have recognized some of the inherent weaknesses of their early products and have launched programs to improve reliability, durability and "maintainability."
A new generation of automated equipment is available, but before you break out the checkbook, don't forget last decade's operational lessons. Technology, driver productivity and maintenance are key to ensuring your automated system is profitable.
Jack Nydam, public works director for Brick Township, N.J., knows this from experience. "When you buy a new truck, you expect it to be perfect," he says. "Just like anything else, you start it up and go down the road, and everything seems to work. The challenge for trucks is maintaining them. There are so many components - hydraulic lines, electrical parts, air conditioning - that you have to stay on top of them."
When Brick Township first automated its system, it took awhile for mechanics to adjust to the maintenance regimen. Consequently, some components failed, Nydam says.
Mechanics soon learned each component's adjustment cycle. "The arm on the back of the truck has to be adjusted monthly," he says. "We weren't doing it at first, and the rollers were starting to wear, which cost us some down-time."
The Truck Stops Here The Achilles heel of automated collection vehicles is the hydraulic system. A truck will make between 900 and 1,200 lifts per day, placing stress on the hydraulic system, primarily the flexible hoses used on the arms.
Although many of the hoses are easy to replace, the additional time needed to clean up a hydraulics spill while on a route, and the accompanying damage claims paperwork resulting from the spill, can be aggravating.
In addition, the bodies of some automated collection trucks can wear out earlier than other parts of the truck. The city of Los Angeles, for example, has found that some of its 500 automated trucks aged earlier than expected, says Enrique Zaldivar, program manager with the solid resources collection division of the bureau of sanitation.
The city now is considering body-only replacements, keeping the old chassis, Zaldivar says.
Many equipment manufacturers are looking to extend body life with a harder alloy steel in increased wear areas, such as the floor underneath the packer blade where broken glass, sand and dirt fall, then grind back and forth between the packer blade and the floor.
This problem is more prevalent in recycling and greenwaste programs, and is the reason why the city of Los Angeles experienced accelerated body wear, says Charles Spang, superintendent of the city's bureau of sanitation. Los Angeles wants a vehicle that will last as long as the chassis underneath it, Spang says.
Fortunately, manufacturers are working on these problems. "We've actually gotten an increase in the number of years in the warranty," Spang says. "[It's] not quite what we want yet, but I think we're going to get there very soon."
Driving the Technology A debate is raging regarding the sophistication level of automated trucks. Some solid waste managers welcome the idea of collection trucks that can think for themselves, while others believe that increased complexity equals less reliability.
Early automated trucks just consisted of a manual side loader with a crude lifting arm that grabbed a cart and dumped the trash into the hopper. They relied on mechanical stops to control the lifting action, and stories of some automated trucks tossing carts across the street or squeezing carts so tightly the materials could not be emptied were common.
Fortunately, today's trucks rely on computer sensors to avoid the cart-destroying effects of an aggressive lifting mechanism. These sensors are designed to sense the revolutions per minute of the truck and the weight and size of the cart to maximize cart cycle time.
Some trucks include memory return, which allows carts to be placed in the exact spot from which they were lifted. The driver just positions the truck and the onboard computer does the rest.
"Most of my drivers ask for an automatic control button," says Henry Mora, superintendent of the Albuquerque, N.M., residential collection division. "Instead of having three levers to pick up the cart, [they want to be able to] hit just one button to extend the arm, grab the cart, pick it up and put it back down."
Several municipalities also would like to see extended-reach arms. "Manufacturers need to look at them for streets that allow on-street parking," says Lou Guilmette, solid waste manager of the city of Rochester, N.Y.
Longer arms on trucks would allow haulers to get between cars to service the carts, he says. "Manufacturers need to look at equipment that is maneuverable and able to access barrels from a greater distance."
Los Angeles' Zaldivar agrees. "We want to play a little bit with the arms' reach," he says. "We've gone back and forth as to whether it should be a longer reach, risking some of the stability of the truck."
What solid waste managers don't want with increased sophistication is longer truck repair times. "All I can ask for the future of automated trucks is that they be as simplified as possible," says Brick Township's Nydam. "I don't want to have to spend three or four days replacing pistons."
Carts That Keep Going Carts also have improved in recent years with better designs and materials. Only a few years ago manufacturers never offered more than a three-year warranty on automated carts. Now, major cart manufacturers offer no less than a standard 10-year warranty.
In addition, cart durability has improved because of advanced polymers. Whether made from recycled content or with linear or cross-linked technology, endusers can expect today's carts to last approximately 10 years or more.
"The industry has advanced considerably in the past half a dozen years or so," says James Maglio, assistant director of the solid waste recycling department in Clearwater, Fla.
The biggest automated cart problems occur with accessory attachments, such as lids that come off when the cart is dumped or wheels and axles that crack or loosen.
And then there's the weather, which can cause more damage to automated carts than physical abuse. In Rochester, N.Y., for ex-ample, the city sees an increase in cart breakage and damage during the winter.
"But the city of Rochester does something that other municipalities do not do," Guilmette explains. "In the middle of the night, contractors plow the sidewalks. If a person has a trash container out when the plow goes by, the barrel goes for a little ride. Most of the time these carts end up getting cracked."
Instead of buying new carts, Rochester will use a portable plastic injection-welding machine to repair them, which costs approximately $20 per cart.
One of the biggest challenges when selecting automated carts is insuring that they are compatible with trucks. Although volume may vary, carts traditionally are offered in 30-, 60- and 90-gallon sizes in the European square body or the American round body design.
The city of Los Angeles initially had some cart and truck compatibility problems. Consequently, the city purchases only round body carts, Zaldivar says. Truck and cart manufacturers also are required to have a certificate of compatibility.
"When we purchase trucks, we require that they check for compatibility with the carts that we have in inventory," Zaldivar says. "That has worked for the most part, however, there still are problems. We don't always grip the cart and keep it in the gripper. In fact, sometimes we may lose carts in the hopper."
If this happens, Zaldivar says the driver will try to salvage the cart once the load is dumped at the landfill.
Recognizing problems can help manufacturers. They have listened in the past, and understanding what works and what doesn't work in your operations may help determine the future of automated truck and cart features.
Improving collection truck quality and reliability is important, but driver comfort also is key to improving productivity. Among the options that help drivers do a better job are low-entry cabs, sound systems, two-way radios, cameras, remote-controlled accessories and air conditioning, which almost is a standard requirement.
Ergonomics also should be considered as selection and placement of truck controls can be the difference between a comfortable driver who can service 900 carts per day and a driver who eventually may file a worker's compensation claim. Customizing multi-function seats to a driver's physical needs also boosts productivity.
"We're looking at electric mirrors," says Henry Mora, superintendent of Albuquerque, N.M.'s residential collection division. "When the driver has to adjust his mirror, he needs to get out of the truck. It's hard for him to go back and forth until he gets the mirror right or finds a broom handle or something."
Albuquerque also is considering installing cameras in truck hopper areas, Mora says. "We're looking at cameras to show our dumping cycles. We have a tendency to scatter a lot of trash because the guys can't see the cart when it's up there."
The city of Clearwater, Fla., has installed self-lubing components in its trucks so drivers don't need to climb inside the packer body to lubricate parts, says James Maglio, assistant director of the solid waste recycling department.
"That's one of the options we elected to have on new trucks," he says. Lubricating is one of the most important maintenance functions.
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