It’s not called “heavy equipment” just because the machines weigh 100,000 or 1 million lb. or simply because they handle enormous loads. Not long ago, it took a man of considerable strength, agility, and stamina to operate these brawny, dirty, noisy beasts of burden. But then equipment manufacturers expanded into offshore markets. Operators grew accustomed to automobile ergonomics. Electronics powered our homes and businesses. The work force began to age. Women joined the heavy-equipment ranks. The construction industry picked up speed. The supply of skilled operators diminished. Ergo ergonomics.
Although some manufacturers entered the foray as late as five years ago, most started incorporating ergonomic controls and cab features into equipment about 10 years ago. A few ergonomic enhancements made their way into some products as early as 20 years ago-albeit, more to increase the machine’s efficiency than to enhance operator comfort.
“Before hydraulics, we had cable machines with 4-feet-long levers coming out of the floor that required physical strength and dexterity to operate,” recalls George Lumpkins, product development manager for Kobelco America Inc. in Stafford, TX. “Those days are long gone.”
Contrary to the popular macho image of the construction-equipment industry, which might lead you to believe that “the good old boys” were content to just leave things be, owners and operators alike have pushed for a better interface between man and machine.
“In the beginning, a few owners said, ‘I don’t need this stuff,’ and some operators said, ‘The old way is good enough.’ When we went to joysticks, a few people questioned whether the machines worked as hard, but that was 20 years ago,” Lumpkins observes. “The majority of contractors and operators have demanded more comfortable cabs, smoother movements, and easier-to-operate controls.”
According to Paul Rihal, senior service engineer with the Building Construction Products Division of Caterpillar Inc. in Cary, NC, ergonomic enhancements serve a dual purpose-to increase comfort and to decrease effort-thereby appeasing workers while boosting productivity and profits.
“Because the pool of skilled operators has dwindled, when contractors get good operators, they want to keep them. Also, there’s now a different set of expectations from young operators who have grown up on computer games and from people used to certain comforts in their automobiles,” Rihal notes. “Operators influence which machines get purchased. Caterpillar has focused on making the operator as comfortable as possible, which in turn makes them more productive.”
Ed Warner, dozer product manager for Komatsu in Vernon Hills, IL, concurs. “Skilled operators are at a premium, so contractors listen to them. And operators have said, ‘If I’m going to sit here 10 or 12 hours a day, why can’t you make my dozer as comfortable and easy to run as my pickup?'”
“Equipment is often run by laborers with no heavy-equipment training or experience,” observes Rihal. Although this has always been the case, the percentage of such operators has increased dramatically. Intuitive controls that closely mirror automobile controls help to get new operators up and running quickly.
“Most people get in the machine and, without any education or training, are running it unassisted within minutes,” claims Warner. All Komatsu equipment includes single-joystick control of tractor direction and speed. With one hand on the blade and one hand on the joystick, the operator points the stick in the direction he wants to go and twists it to change gears.
Market demand for lower-effort controls with increased precision led to hydraulics, then to pilot, joystick, and electronic controls. Even in the 1970s, when mechanical controls were standard, operators asked for dual-axle “wobble” sticks and reductions in effort and travel.
“As the effort side of the equation kicked in, we had to reevaluate the kind of controls we were using. With mechanical controls, when you reduced effort, the travel went up, which wasn’t very comfortable for the person running the machine all day,” says Rihal. “In the mid-1980s, we went to pilot controls, which stepped down effort without upping lever travel.”
According to Danny Schall, skid-steer-loader product representative for Bobcat in Fargo, ND, the goal of all equipment design is to get more productivity out of both machine and operator. “Many Bobcat operators are their own bosses. Equipment that keeps them on the job longer and producing 100 percent, because it’s easier to operate and easier on their bodies, translates to added productivity.”
Bobcat’s customer polls also indicated that larger contractors around the globe “resoundingly” wanted the same ergonomics for the same reasons. Schall explains, “Contractors felt that if operators were more comfortable, they’d be in the seats longer and owners would see a payback of higher profits.” They were right.
“The operators like the machines so much, they’re pushing them to the limit, which has increased the number of hours they operate the machines and increased productivity,” Warner states.
Holnam Cement uses a Komatsu WA700-3 wheel loader with a tiltable-wheel, single-lever, hydraulic-power steering system at its Midlothian, TX, plant. “Our operators have found that the stick steering makes the overall operation of the machine much easier,” reports quarry supervisor Randal Anderson. “That leads to shorter cycle times and better production numbers.”
“It’s not all about efficiency and money,” Schall reminds us. “Beyond the measurable gains in productivity, the operator feels better when he goes home. He doesn’t have to sit on the couch all night resting up; he has energy to spend with his family, to do other things.”
With today’s power controls and transmissions, operators can move machines weighing up to a million pounds with 2-4 lb. of pressure and operate implements with 2-3 lb. of force. “You can use your fingertips to move a 100,000-pound excavator and fill its 3,000-pound empty bucket with 15,000 pounds of dirt,” says Lumpkins.
John Deere Construction Equipment Company has combined functions into single controls to reduce effort and travel and to smooth out metering characteristics, points out Phil Larsen, manager of product planning, power tractors, and scrapers in Dubuque, IA. The right T-bar on Deere’s G- and H-series dozers, for example, controls three functions that previously required three levers and now enables the operator to raise and lower the blade by moving the lever forward and rearward, to tilt the blade to the left or right by moving it side to side, and to angle the blade by twisting the lever. The right T-bar controls steering and speed. There are also acceleration and deceleration foot pedals.
“The old machines had more levers and pedals than the operators had hands and feet. Combined-function controls not only streamlined operations, they also made the machines easier to move, reducing wear and tear on the body and, at the same time, upping productivity and precision,” Larsen states, adding, “Not wearing out operators is a key issue,” because they work longer hours these days.
Owner/operator Rick Tharaldson of RCT Enterprises in Bremerton, WA, does a “little of everything” with his new Deere 450H LT dozer. “I hate used equipment, I hate pedal steering. With my old foot steer, I felt like I was tap dancing all the time. The single lever is much better. I also like the hydrostatic steering, which is good for backfilling around houses; I can get close and don’t have to fool around. I use the decelerator quite a bit too. It’s on the opposite side from the decelerator on my old machine, but I caught on quickly and adapted.”
Although the main ergonomic characteristic that owners look for is linear response, creature comforts have moved to the forefront. This focus has been driven in large part by the desire for the features found in automobiles.
“I’ve been in the industry for 20 years, and during that period we’ve seen a tremendous improvement in the operator environment,” remarks Lee Haak, wheel loader/truck product manager for Komatsu. “Older people think the younger operators are spoiled, and the younger operators can’t understand how the older guys ever put up with such crude machines.”
Standard ergonomic features now include hydraulics, inclined dashboards, adjustable armrests and seats, hot/cold storage compartments, operator weight adjustments, ventilation, and ample leg room. Air conditioning, one-hand power controls, and user-friendly positioning of instruments are quickly becoming standard. On the latest Bobcat G-series cab, for example, the ergonomic features were designed primarily to increase operator comfort. Adds Schall, “Because a skid-steer loader has no suspension, we looked at ways to improve the ride in our machine and designed a much better suspension seat that takes the bumping and jarring out of the ride.”
Sixty-five-year-old Harold Lyons of Lyons Excavating in Brownsburg, IN, likes his John Deere 450H just fine. “I’m old, I don’t like a lot of vibration, and I’ve got bad arthritis in my shoulder. I’ve been excavating for 32 years and owned about 20 dozers. They’re not my favorite machines; I like excavators better. But this 450H is more fun than work. The controls are spot-on, the visibility is super, the seat is comfortable. It doesn’t bother me at all to run the Deere. I really like the 450H; it’s so smooth.”
One of the earliest ergonomic changes appeared in seat belts. “The old, two-piece seat belt had a big buckle that fastened in the front and dug into your stomach,” Komatsu’s Warner recalls. The seat belt also dropped to the floor of the cab, where the operator would step on it and get his clothes dirty when he put iton. Many operators wouldn’t wear them because of the discomfort and hassle. “If you’re running a piece of equipment on a rocky site or steep grade, you want the added protection of a seat belt,” Warner notes. Komatsu, similar to other manufacturers, has taken the automotive approach with retractable seat belts.
Drummond Dolomite Inc. (DDI), a division of Osborne Inc. of Cleveland, OH, operates a Komatsu WA700-3 wheel loader that includes an air-suspension seat with a self-contained air compressor at its base, which electrically adjusts to different-sized operators in seconds. Rubber and silicone viscous damping mounts also minimize vibration and noise. “The fatigue level of our operators has declined since we bought the WA700-3,” claims Gib Aikey, DDI plant manager. “The loader provides them with a comfortable and quiet shift.”
Larsen ticks off a laundry list of ergonomics on John Deere seats alone: suspension; lumbar supports; independent adjustments for height, weight, seat-back angle, and leg-support angle; and wider and adjustable armrests. “The placement of the controls relative to the seat was important,” states Larsen. “Likewise, foot controls and rests had to be adjustable and positioned properly relative to the seat. Though it might not be a high priority with other machines, it’s critical with dozers. A dozer works on steep terrain, and the operator needs good bracing support for his feet.”
Lumpkins claims that today’s manufacturer would be hard-pressed to sell a new piece of equipment without suspension seats and air conditioning. “Now you’ve got climate-controlled cabs, suspension seats, and a quiet, smooth ride, so you can go home at the end of the day without ringing ears and an aching back.”
Caterpillar’s expert operators tested out the implement control lever for its 924-G wheel loader. “At first, they didn’t warm up to it because it was different and oversized,” says Rihal. “But our research had determined that operators typically used the control as a handrest. Traditional levers were skinny and pointy, and most people who ran these machines for a living had big calluses in the middle of their palms. The control not only is intuitive, it also conforms to the person’s hand. Substantially, customers in the field have endorsed the new design.”
Cabs have been reengineered to eliminate posts and supports to allow operators greater visibility out the front, rear, and sides. Although this may be considered more of a safety precaution than an ergonomic feature, the ability to achieve a clear line of sight simply by turning your head 90º from a seated position, versus having to twist your body to look around your work environment, is definitely operator-friendly.
Equipment has also been reengineered to decrease vibration during operation, a once-pervasive characteristic that can cause significant discomfort. Similarly, hydraulics and advanced hand controls have greatly decreased the amount and effort of arm and leg movements, thereby reducing fatigue.
A contractor outside of Madison, WI, finally convinced one of his old-time operators to switch from a 1987 Komatsu dozer to a new D155AX-5. “He just loved that old dozer and didn’t want to change, but once he did, he was happy,” Warner reports. “He’s been running it for about a year. When I visited him recently, he said, ‘I’m not as tired at the end of the day. I don’t feel like I’ve been in a rodeo or like my back has been crunched up all day. I get out and feel good. I also don’t worry about remembering my earplugs.'”
Some manufacturers, including Komatsu, have repositioned monitor panels and brightened the digital readouts so operators can read them in sunlight without leaning closer or to the side. Entrances to cabs have been widened; handholds, rails, and steps have been added and strategically positioned to make it easier for operators to get in and out of cabs. Komatsu, for example, follows a “three-point-stance” design standard for entrances: making sure the operator always has either two hands and a foot or two feet and a hand in contact with a hard surface.
Equipment ergonomics-particularly hydraulics and hand controls-has helped to level the playing field for older, smaller, and physically challenged workers. Accordingly, it has helped alleviate the challenge of finding and retaining qualified operators.
“In the past, the typical operator was an agile, 6-foot-tall or taller, 200-pound, muscular linebacker type,” Warner says. “Today you see all types of body frames and a greater number of women.”
According to Bobcat’s Schall, the stigma against female and smaller male operators is being put to rest. “I think the market is forcing contractors to quit stereotyping. With all the construction going on and the shortage of operators, they have to hire the best available person at any given time to get the job done.”
When Bobcat places prototype machines in large construction companies, about half go into female hands and the other half into male hands. “But we don’t specifically target genders. We try to get a good cross-section of the general operator population,” Schall adds.
Bobcat does offer pedal extenders to operators who are “height challenged.” “We also have several physically disabled customers who can get into and run these machines just like anyone else. We try to accommodate as many body types and situations as we can, but unfortunately we can’t always do so. For instance, there’s a 7-foot-tall operator in Cincinnati running our equipment, and he’s just more person than our machine can hold,” says Schall.
Ergonomics also makes it possible for operators to work more comfortably with existing physical challenges and helps delay retirement for others. “The effort required to operate the older equipment day in and day out, year after year, took its toll on the bodies of some operators,” Larsen notes. Some people whose back problems prevented or made it difficult for them to work can run ergonomic equipment with little or no limitations. The reduced motion, effort, vibration, and noise also help prevent further deterioration.
Keeping the Big Boys in Service
On the upside of the equipment-service coin, increased operator comfort has translated into improved upkeep. Schall tells of one operator who used to dread coming to work, but since he’s been running a new machine with suspension seats, he’s glad to come to work. “Before, he didn’t care who else used his machine or what condition it was in. Now he makes sure his machine is in tiptop shape and won’t let anyone else near it.”
“When an operator likes a machine, he tends to take better care of it. If something goes wrong, he reports it before it becomes a bigger problem,” observes Warner.
Access to the engine and other repair areas has been improved in some equipment. Electronic diagnostics and pressure monitors have also been added.
“The old manual systems had big brakes and clutches, mechanical linkage, and asbestos flying everywhere. Hydraulics added a new servicing challenge. Before the onboard computer diagnostics systems, you needed clutch and test equipment as well as pressure gauges, which exposed you to some risk, dealing with 4,000 to 6,000 psi,” recalls Kobelco’s Lumpkins. “With modern machines, you sit in the cab, dial-in pressures and flows, check-out the engine rpm, and run more than 60 diagnostic tests by punching buttons.”
Still, when something goes down, a trained technician is usually required. Although comfort and cost savings can be gained from eyeballing a problem on a computer readout and communicating it to the technician from a cell phone in the cab, some wrenchers yearn to do more of the maintenance and repair work themselves.
“With mechanical controls, the contractor or operator could find the loose bolt and tighten it or find the link that came apart and hook it back up,” says Caterpillar’s Rihal. “With pilot controls, he can still do basic maintenance himself, but he might need either special tooling or a dealer-trained mechanic for repairs.”
Bobcat wanted to give customers more servicing flexibility and control. “Things were getting too complex, too technical. If you’re a do-it-yourselfer, as many Bobcat owners are, you want to at least be able to troubleshoot for yourself. So we gave them the capability to diagnose the problem via a diagnostic module imbedded in the instrumentation panel,” Schall says.
“The computer has allowed us to implement many ergonomic features. Obviously that adds complexity,” Larsen notes. “Many contractors and operators like to fix their own stuff. You see the same thing with cars, where shade-tree mechanics could fix things on the weekend, but now they can’t.”
“Everybody has that phobia to some degree,” agrees Schall. “But if you want specific attributes in any equipment-from stereos to lawn mowers to jumbo jets-you have to put up with a certain amount of electronics.”
Adds Larsen, “Electronics have become more robust, and when designed properly and protected from the elements, they have infinite life. It has reduced the contractor’s or operator’s ability to do his own repairs. The benefits are paid on the other side in increased productivity, flexibility, and ease of use.”The Ongoing Evolution of Equipment Ergonomics
Initially, it was cost-effective to incorporate ergonomic controls only into larger machines. Over the past five or so years, it has become feasible to bring hand controls and other ergonomic features to some smaller machines. Today equipment manufacturers update and add ergonomic features to keep ahead of-or catch up with-the competition. Consequently, the types of ergonomic features available today vary little between machines and manufacturers.
Ergonomic features first appeared in excavators before making their way into other construction equipment, most recently to dozers. “Dozers have always been the rough-and-tumble part of the construction industry, out there doing the pioneer work,” remarks Warner. “Operators kept telling us that our excavators and loaders are easy to use and the cabs are nice; ‘Why can’t you do that in our dozers?’ So as the technology evolved, Komatsu transferred those ergonomic features to the dozers.”
“Our excavators have been pilot-controlled for a while, and now our tractors and wheel loaders are too,” Rihal points out. “Right now we’re seeing an integration of controls.” He explains that on older machines, you’d have a gear-shift lever mounted on a steering wheel column, both manipulated with your left hand, and two or more implement levers manipulated with your right hand. Now you might have a direction-changing switch on a bucket-control lever, enabling you to perform both actions with your right hand on a single control. On that same lever you might also have a switch that lets you shift down one gear.
Virtually all excavators are electronically controlled. The latest innovation is mode selectors, which allow the machine to conform itself to various job conditions based on the mode the operator selects. The drawback is that few operators use them because they’d have to repeatedly stop and reset them. Most operators find it faster, if not easier, to bypass the mode selectors, which have four to nine modes.
Kobelco has gotten around this with a “fuzzy logic” system that senses what the operator is trying to do and automatically reconfigures itself. Lumpkins explains, “If you’re trying to dig the side of a bank, it’ll change the characteristics of the hydraulic system to give you better power. It will react to whatever the operator is doing: cutting a slope, tamping, scattering gravel.” These responses happen within a few seconds of the operator’s change in action. You can also shut off the mode selector. “We’re going to see more of this kind of intuitive control in future machines.”
Noise reduction, which has been a concern in Europe for years, is getting more attention in the United States. Komatsu, for instance, went to a sound-deflection radiator nose that throws the fan sound and exhaust 33 ft. into the atmosphere, away from the operator and other laborers.
Kobelco’s response to what Lumpkins describes as a “huge push” toward quieting the inside of cabs has been to isolate the cabs with either rubber or viscous silicon mounts, which keep the floor of the cab out of contact with the machinery. “We’re getting heavy equipment running at full power with the inside-cab noise level in the low 70-decibel range, the equivalent of your car running down the road.” The sound-reduction effort doesn’t end with the cab. According to Lumpkins, it’s possible to hold a polite conversation right next to one of the company’s new Dynamic Aceras while it is operating.
Some contractors resent paying the extra cost for features they feel they don’t need or want. Most manufacturers market equipment worldwide, however, and an increasing number of states have laws requiring construction projects to run only at certain hours because of noise. Warner says if manufacturers offered 50 or 52 options, with separate manufacturing specs for different countries and different states, it would increase equipment costs.
“Contractors don’t like that argument. If I were a contractor, I might not either,” empathizes Warner. “A contractor in South Dakota might not have to worry about sound yet, but he will probably have to. We’ve got to think about our brother contractors in California, New York, and DC who need these features today. We need to think about tomorrow, and tomorrow is two or three years down the road.”
Although most manufacturers offer ergonomic options, some features, such as joysticks and a closed cab, are considered standard for certain equipment. Many manufacturers continue to debate the merits of going the way of large automobile makers-rolling ergonomic features into predefined packages.
That is not likely to happen at Bobcat. “We concluded that contractors and owner/operators want what they want. We offer most of our ergonomic features as options to give customers the flexibility to get a base machine or to choose individual options,” Schall says. Several new ergonomic choices are on Bobcat’s drawing board. “The drive for ergonomics is going to continue not only with our machines, but also throughout the industry.”
Adds Rihal, “Ergonomic needs don’t change over time; we know the dimensions and dynamics of the human physique we deal with. But as new technology opens up, we can use it to design construction equipment that caters ever more closely to the human body.
