May/June 2012
Greater speed, efficiency, productivity, comfort, and safety: That’s what
manufacturers say they deliver with their newest material handlers. As
emissions standards tighten, some see electric engines as the next big thing.
By Jim Fowler
In July 2011, a manufacturer conducted a market research study among 21 “high-profile” scrap companies that asked for their wish lists of material-handler features. The top request was longer reach, followed by easy maintenance, better diagnostic capability, stronger grapples, and nicer cabs. Manufacturers have aimed to give customers what they want, with their newest models featuring many of those improvements (setting aside stronger grapples, which are beyond the scope of this article) and other innovations designed to improve operating efficiency, safety, and productivity.
Yet as significant and numerous as those changes are, the most notable change to come in material-handler design has nothing to do with customer demands and everything to do with tighter federal emission standards. The Tier 4 standards are leading just about every company that makes machines with internal-combustion engines to redesign what’s under the hood in time for the January 2014 implementation deadline. “Equipment manufacturers are going through unprecedented changes for their machines,” one representative says. “It’s huge.” Achieving these stringent emission requirements “has required a complete re-engineering of the machine,” another company’s rep says. “Right now there isn’t a company out there that isn’t putting all of its engineering efforts into Tier 4 engines.” When a machine meets Tier 4 standards, he says, “the air that goes into the engine will be dirtier than the air that comes out.”
That’s great news for air quality, but these companies point out that such changes can have other implications. Because Tier 3 and Tier 4 engines must burn all of their emissions, they run at significantly higher temperatures. “The engine gets so hot burning the soot from the diesel particulate filter that more efficient and higher-powered cooling systems are a must,” the company rep says. Ironically, to run at those temperatures and to operate such a cooling system, material handlers that meet Tier 4 standards consume more fuel than earlier models. Another manufacturer points out that “interim Tier 4 and Tier 4 engines will have more auxiliary components that have service elements,” most notably diesel particulate filters.
Faced with these emissions mandates and their potential drawbacks, manufacturers are looking at other ways to increase fuel and operating efficiency and reduce operating costs in addition to providing the features on recyclers’ wish lists. Here’s a look at some of the latest trends and features in material-handler design.
Hydraulic highlights
Improvements to material-handler hydraulics can save fuel and improve operating efficiency, companies say. A fuel-saving feature one company introduced two years ago is an energy-recovery cylinder on the material handler’s main boom that provides lifting power to the boom. It’s a large nitrogen cylinder that, in simple terms, works like the mechanism in some automobile trunk lids, a company spokesman says. “When you close [the lid], it charges the cylinder, and when you open it, it pops up. It relies on kinetic rather than external energy.” With that assistance, raising the boom requires less horsepower. “Handling scrap, you’re constantly raising and lowering the boom,” he says, so the constant charging of the energy-recovery cylinder “allows the engine to run at [fewer] rpms, with an ensuing fuel savings estimated at 15 to 20 percent, depending on the application.” Machines with energy-recovery cylinders also can have slightly smaller hoist cylinders. Smaller cylinders use less fuel, lower pump speeds, and less oil flow in the hydraulic systems, and they produce less noise and exhaust emissions, he adds.
Computer-controlled hydraulics—electric control of pressure-load sensing, pressure compensation, and flow-on-demand pumps—can get “the highest possible efficiency out of all of the system’s actions,” a manufacturer’s representative says. “The complete cycle times of machines are extremely fast now, which equates to higher productivity, and that’s what it’s all about. Technological advances in hydraulics combined with computer control [improve] quickness and efficiency.”
Another manufacturer agrees that electric controls react faster than mechanical hydraulic controls, which helps the operator move the unit more precisely and quickly. “You don’t have to anticipate moves nearly as much as [you do] with hydraulic pilots,” he says. Without computer controls, he explains, “when the operator moves the joystick, that motivates a hydraulic plunger. It releases fluid, telling the valve at the valve bank what to do. There is a slight delay. When electronically controlled, an electrical switch sends an instantaneous signal to the valve bank, prompting an immediate response.”
“The science of flow share has improved greatly,” a different manufacturer observes. “Just as fuel management in engines has become more and more precise, … it’s the same with hydraulics. The right amount of pressure and flow are computed, so you don’t have fluids going over reliefs and wasted energy. That’s why you can do more with the same size machine—[with the] same horsepower. We can go faster and smoother, and the machine is easier to control.” Another advantage of computer-controlled hydraulics is the “ability to adjust the speed and ramp of the joystick to be faster or slower from the cab control screen, without the operator physically changing any valves,” a manufacturer says.
One company is bucking this trend, however. It has removed the computers from its hydraulic systems, which now run on manual controls, or pilot pressure. Manual control makes it easier for customers to maintain their own machines, a company rep says, which some customers prefer. “This allows the operator to use a flow meter or temperature gauge to determine the problem and correct it without calling in a [technician] to hook up a laptop.” That said, these material handlers are not entirely computer-free. “There is a computer for the machine’s engine,” he explains, “because the fuel system runs at such high pressures compared to previous engine pressures.”
Another manufacturer says that for his company, there’s no going back. “Everything is computer-controlled now. Mechanics go to a machine, plug in a laptop, and get a quick diagnostic. It’s a new game out there.” The machines are easier and safer to operate, a different company’s rep says, but he agrees that computers make maintenance more complex. “Most maintenance departments have to rely more on their dealer than previously. It’s not just a mechanic turning a wrench anymore. It’s an electronic expert and a computer operator as well as a mechanic, and [it] requires a higher degree of training. The customer can still do routine things, such as greasing and checking the fluid levels,
but comprehensive diagnostics of the machine normally requires dealer support.”
Diagnostic Developments
Though they can add complexity, computers also can make things clearer. In material handlers, the trend is toward more computer data collection and monitoring of performance and productivity. “The data tell you how many loads the machine has done, cycles per hour, and idle time,” a manufacturer says. With this information, supervisors can compare machines and operators “to see who is getting the most work done” or to adjust operations for greater efficiency. For example, “say a shredder has two 100,000-pound machines feeding it. An analysis of their idle time may reveal that one 130,000-pound machine would do the job.”
When it comes to maintenance, “the machine will tell you what to do and when to do it,” a manufacturer says. For greater clarity, one company has changed its cab display to show not error codes, which an operator must look up or memorize to decipher, but regular-language descriptions of the problem. “This helps the operator quickly determine if he should keep running or shut the machine down,” the representative says. “He is more informed and more comfortable with what’s going on with the machine. If necessary, maintenance can tell the dealer what, precisely, has failed, so getting the right part requires only one trip and [results in] a quicker repair.”
Some machines have GPS and wireless Internet or cellular communications systems to further alert people when something is wrong. “You can have [the material handler] send a wireless e-mail to someone in the office or to a computer in the maintenance department [when] there is a problem, such as the machine being low on oil,” the manufacturer says.
Computer-controlled diagnostics can lower maintenance costs, these companies point out. “Sensing devices will tell the operator when filters need to be replaced and when there is a bypass in the filter, [which is] a big deal. It will tell you on the screen which filter is [being bypassed] so it can be changed immediately,” one company rep says. Further, “old systems rely on periodic changing” of items such as filters. “Now filters have sensors on them to warn the operator how much time is left” before they must be replaced. “That allows you to run filters longer—a potential money saver—than at a set interval,” he says.
Comfort and Safety
Cab ergonomics, access, and comfort were buzzwords a decade ago, and manufacturers continue to improve and refine the space a material-handler operator occupies eight to 10 hours a day. One manufacturer boasts that his cabs are “maintenance- and operator-friendly, with easier controls and more standing room.” Did he say standing room? Yes—he explains that his machines’ larger cab is “safer for training purposes, as it allows for a couple of people inside the cab who can stand alongside the operator while directing or training him.” Another company has removed the steering wheel in the cab of its larger machines and replaced it with one or more joysticks to give the operator more space.
Hydraulically operated cabs are far more common than a decade ago. “The ability to adjust the cab to different height levels allows the operator to see into a trailer or baler when he’s moving scrap,” one manufacturer says. Another company has a cab that comes to the ground for safer entry and exit. Companies tout their larger cab windows and rear-view/backup cameras, which improve operator visibility. One company has added another camera on the machine’s right side to provide a view into what was a blind spot. On those windows, bulletproof and high-resistance glass and/or steel bars can protect operators from flying debris.
Buyers are placing more and more emphasis on material-handler safety, these companies say. In addition to their cab-based safety improvements, they note hydraulic safety features such as hose-rupture valves and cylinder valve locks that mount directly over the boom and arm cylinder ports. The latter “prevent an accidental lowering of the boom should a hose burst,” explains one manufacturer, who notes such locks are now required. Another company studied its material handlers in action and decided to flip its machines’ boom cylinders around so they’re better protected when the handlers are close to a truck or railcar, preventing damage during loading and unloading.
Load sensors improve safety as well. “Say the outriggers are up, and the operator wants to lift something,” one manufacturer explains. “The load sensors will warn the operator when he is approaching maximum lift. Once he hits that point, the machine won’t be allowed to lift any more, preventing it from tipping over.”
What’s the Trend?
Most companies offer a variety of options for each material-handler model. They have noted a few trends among their customers:
Go long. In booms, “everybody wants reach,” one manufacturer says. “It’s all about reach, almost more so than power.” Part of the reason, he says, is that longer reach means less moving around. “It takes time to reposition, but if you can sit in one spot and get everything done, you’re ahead.”
It’s not just large yards that want more reach, another company’s rep points out. Buyers at a smaller scrapyard might consider “the size of the trailers they’re loading and unloading and the real estate they have to work with when specifying reach,” he says. “They may stack material higher than a larger yard that has more space,” giving them the need for more reach.
Back to tracks. Twenty years ago, these companies estimate, nine out of 10 material handlers in scrapyards were track or crawler machines. Eight years ago, the ratio was closer to six or seven tire machines for every three or four track machines. Today, an estimated 75 to 80 percent of the U.S. material handler market rides on tires.
At least one manufacturer sees the pendulum swinging back to tracks. He thinks the move to tires was “mainly due to the mobility processors felt they must have. We are now seeing the opposite, with more customers ordering a track version [of a material handler] to replace their wheeled machines.” Another vendor strongly disagrees with that assessment, however. As more scrap processors hard-surface their yards, the more likely they are to want tires, he says, because tracked machines “chew up” pavement and concrete.
For something completely different, at least one manufacturer offers a truck-mounted material handler, which he says is gaining interest in rural areas. “If a dealer doesn’t have a peddler base [able] to bring in scrap from farms and other outlying areas, with a truck-mounted machine he can offer that service,” he says. “Depending on the scrap being collected, it could be a flatbed or dump trailer. The material handler’s hydraulic pump is [power take-off]-driven by a shaft coming directly off the truck motor.”
A continental divide? There seem to be conflicting opinions about advances in magnet controller design, specifically, between proponents of European and U.S. systems. One manufacturer says he’s gradually seeing “the more modern electronic European systems” in the United States, though most material handlers still use U.S. generators. The latter are considered “old technology,” he says, but “they work.” Further, he says, “the U.S. systems can be repaired quickly and easily, [while] there is not the support system here for the European systems. They are more difficult to repair and have to be replaced if they don’t work.” A representative of a different company agrees with that assessment. “If the European controller goes out, you can’t get parts for it here, so you have to replace the entire unit. With the older U.S. system, you replace the part and keep on going.” He, too, believes the majority of material handlers in the United States still use U.S. magnet control systems.
Electricity and Alternative Fuels
To avoid the emissions concerns internal-combustion engines create as well as rising diesel fuel prices, some yards are taking another look at electric-powered material handlers. Although they’re still not common in scrapyards—they’re an estimated 1 to 5 percent of the U.S. market—the popularity of electric machines “is beginning to take off,” one manufacturer’s rep says. He asserts that electric machines can result in operational and maintenance savings of at least 50 percent over diesel machines. A different company’s representative pegs the savings at 70 percent. “Assume a diesel machine at a shredder running 10 to 12 gallons of fuel an hour,” he explains. “Multiply [that] by the cost of diesel” to get the fuel cost per hour, “and compare that number to a cost of maybe $7 an hour for electric.”
Manufacturers of electric material handlers point out these machines’ other benefits, too. Electric engines generate zero emissions, which makes them attractive for inside use. They operate at a cooler temperature and require less horsepower. The cooling system only cools the hydraulics, not the engine, which means the engine does not need to work as hard to keep components cool. Also, once the electric engine gets up to speed, it runs at a constant rate, which can significantly extend the life of the hydraulic pump, they say. “Pedestal-mounted electric machines with long outreaches and wide coverage are the future in material handlers,” one manufacturer says. “High stacking, minimizing real estate consumed, lower operating costs, and eliminating fuel costs are all trends happening now and into the future.”
A pedestal mount is no longer the only base option for electric machines. Mobile electric-powered material handlers are finding their way into scrapyards, particularly for feeding large shredders and at port facilities. Most shredders run on electricity, one manufacturer points out, so that’s an ideal location to plug in an electric material handler, whether it’s on a pedestal, tracks, or tires. Yards can tether the latter two designs to run 100 to 400 feet in any direction. A sales representative from another company also expects more scrapyards to purchase mobile electric material handlers. He specifies that these will be larger machines to feed not just shredders, but also big shears and balers—scrapyards will use them anywhere a material handler is sitting in one spot all day, he says.
A representative from a different company acknowledges scrapyards’ new interest in mobile electric-powered material handlers, but he cautions prospective buyers to consider such machines’ drawbacks, such as their limited range and the need to run electricity to where they will operate. He believes the operating cost savings will be in the 25 to 30 percent range compared with diesel, but electric engines cost “substantially more” up front, he says. One manufacturer estimates an electric engine costs about 10 to 20 percent more than its diesel counterpart. Another source points out, however, that electric motors require a lot less maintenance (there’s no motor oil or air filters, for example), and they tend to last much longer than their diesel counterparts.
Though these companies could name few, if any, customers who use biodiesel as a substitute for petroleum-based diesel fuel, some believe compressed natural gas might show promise as an alternative fuel for material handlers. “I think there is some pressure today to find a way to use natural gas as a fuel because it burns very clean and remains very cost effective at this time,” one manufacturer says. “It’s a big engineering challenge,” he adds, because “natural gas does not have quite the performance of diesel, so you need a bigger physical engine, and that requires the re-engineering of the whole package to make it work. Tanks for natural gas are large and create some safety issues as well. The technology is not quite there, but we are absolutely looking at natural gas.”
Other companies also say alternative power solutions might be on the horizon, as well as further diagnostic capabilities. One source thinks these machines might be close to their peak hydraulic performance, however. “As technology continues to improve, we’ll be able to tweak it, but I think most of the low-hanging fruit has been gathered.” Further improvements might come at a much higher cost, however, and cost was the third-most-important factor buyers say they consider in their material-handler purchases, after performance and serviceability. “You have to ask, is there enough benefit in the [new] technology for the customer to pay for it?” one representative says. “The price for a small, incremental improvement may not be cost effective.”
Jim Fowler is retired publisher and editorial director of Scrap.
It’s a Hard-Knock Lifet’s a hard-knock life
What’s the expected life span of a modern material handler? The consensus appears to be 10,000 hours at a minimum, but what happens past the 10,000- to 15,000-hour mark can depend on the owner’s perspective on rebuilding versus replacing. “They all last 10,000 to 15,000 hours before you have to do anything major, such as rebuild a motor or pump,” says one company rep. With one such rebuild, another source says, “we’re seeing customers put 30,000 to 40,000 hours on some of their machines. … The frames, booms, and sticks are lasting long enough to do that. Eight years ago, 10,000 to 15,000 hours would have been typical” for the entire machine. A different company representative agrees that scrap processors are keeping their machines longer, but he pegs their expected life span at 25,000 hours. In a survey one manufacturer conducted of scrapyard material-handler owners, it found that 72 percent of surveyed companies keep their machines more than 12,000 hours, while 34 percent keep their machines more than 18,000 hours.
Other companies see their customers coming out on the “replace” side of the repair-versus-replace decision. “The bigger scrap companies tell me it costs less to [replace] a material handler every 10,000 hours than to keep it,” one says. Another adds, “it depends on how [customers] want to take care of them. Larger companies may always want to have fresh machines in the production areas, so at 10,000 to 15,000 hours, they may move [those material handlers] to feeder yards. Smaller yards may want to hold on to them.”