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It’s an unfortunate word: dozing. It does nothing to reflect the accuracy and speed that good operators can deliver with these most basic of earthmoving machines. By Paul Hull
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Everybody in the construction company seems to know who the best dozer operator is, just as youngsters know who is best at third base, who owns the best math brain, and who is the best quarterback in the school. We recently talked with a group of construction workers taking a lunch break from the construction of new stores and apartments about their dozer operators. There was no doubt in their minds who the best dozer man was. They immediately pointed to a young man who was younger than all but one of the workers. Frank Ereth grew up on a farm and started using machines as soon as he could reach the pedals. He had several years’ experience maneuvering machinery by the time he left high school. "Frank’s too modest," added his foreman. "He understands the dozer, but the most important thing is that he’s constantly learning new ways to control it and make it produce." It seems that some people take to dozers as others take to excavators or trucks. Not only do they know how to run them, but they enjoy running them. "Frank probably talks to the machine when they’re working together," joked another coworker. Of all the qualifications and skills mentioned by those interviewed for this article, experience was the most frequently given reason for an operator’s success. When Ereth had the chance to use a new dozer without all the levers to work, he loved it. It made his job easier and more enjoyable. Another experienced dozer operator is Chad Kosbab. He’s a foreman now but uses a Bobcat skid-steer loader with a blade attachment for much of the accurate dozing needed for new-house construction. "I couldn’t believe how much more comfortable the new machines are," he smiles. "I could go all day with very little fatigue." Other contractors told of how one worker will get along with a dozer right from the start, and then it becomes a definite partnership between man and machine rather than a conflict of wills. Terry Nelson has been operating dozers for a long time but says there is always something new to learn. Last year his company built a golf course; it turned out to be quite a change from their usual roadwork. "I learned more about backdragging on that one project than in all my previous years," Nelson states. "It’s too easy to forget that a dozer works in both directions, and that job reminded me of the concentration required for good results."
Often the experience garnered by an operator is on a particular machine, not necessarily a new one. The very first contractor we spoke to, Keith Mitchell of Mitchell Construction in Minnesota, has more than 30 years’ experience on all kinds of construction equipment. He remarked that he would not be a good operator for a new dozer because he had not been trained to run it. He told of how his brother had jumped into a new machine within minutes of its delivery at their yard and turned it over only seconds later, with the manufacturer’s representative shaking his head in awe. "He thought he knew everything about machines," recalled Mitchell. "But he only knew everything about old machines." The importance of good training was emphasized by several owners, usually with a comment such as "Machines are expensive enough today without allowing some cowboy to wreck one because he never bothered to read the instructions or learn about its controls and capabilities." Some larger contractors whose crews have to work in other states or hundreds of miles from their home base have established their own training facilities. When an operator goes 300 mi. away to run an expensive dozer, the contractor wants no errors in operation or maintenance. "We’re very thorough with our training," notes Don Rhoads at Oftedal Corporation, headquartered on Yellowstone Hill in Montana but with projects all over the western states. "We have a big facility down in Casper, Wyoming, and we make sure that operators know how to run their machines for the best productivity." In terms of the "fancy" controls on new dozers being a help or a hindrance to experienced operators, Rhoads remarks, "They’re like today’s cars. They keep getting better all the time - easier to operate, more productive. What a relief for a dozer operator to get away from all that pushing and pulling of levers and to experience some comfort during the operation!" He does not think the quality of operator is going down (as some old-timers will say), but he does assert that, especially in earthmoving with dozers, experience usually makes the operator better. "There’s a skill in moving that earth from there to here in the most productive manner, and the more you do it, the better you are at it." Contractors who find good operators are unwilling to lose them, and that might mean keeping them on the payroll over the winter in those parts of the country where earthmoving slows down as the pumpkins reach maturity. Several employers noted that good operators are generally good employees too and will help with winter maintenance and repair. "We find that operators who drive their machines well also like to know as much about their components and functions as possible." A contractor with only a few employees is not usually in a position to finance private training facilities, but the importance of training is recognized now more than ever. The manufacturers and their distributors provide courses, with training virtually becoming a condition for purchase of a new machine. The bigger (and probably more common) challenge is training somebody to use an old machine with its levers, pedals, and vibrations. Apart from the productivity issue there is the matter of safety. States one contractor, "A dozer that is down costs money and the costs are much greater if both dozer and operator are down because of an accident. Our business prospers on the constant use of our machinery and employees." Today’s cabs have contributed much to safer work. If your dozer does not have a cab, the operator should dress as he would for other heavy equipment, with a hardhat and eyesight and hearing protection. Seat belts should be worn in dozers. The engine should be turned off if the machine is unattended. Jumping on and off might appear to show enthusiasm, but it is dangerous. After use, the blade should be landed on the ground, the brakes set, the power turned off, and the machine put in neutral. Passengers should never be allowed on-board.
Manufacturers are justifiably proud of the advances made in dozer control in recent years and will acknowledge that many of the improvements in engineering and design come from the comments of users in the field. The standard of maneuverability has risen to enable full-size dozers to be controlled as easily as toy dozers are maneuvered across the living room floor or the backyard. "To develop our H Series machines, we went straight to the people who know our products best-our customers," affirms Rusty Schaefer, Case Corporation marketing manager in Racine, WI. There are five dozers in the H Series: 550H, 650H, 750H, 850H, and 1150H, with power ranges from 67 to 119 net hp. From our conversations and observations, today’s dozer operators are not necessarily the big, husky men that have always been the public’s image of these professionals. Many of them are small and lightweight. "If dozing were simply slamming a blade into the earth and moving it around in a random pattern, productivity would be low," remarks operator Rob Wallace. "I couldn’t work like that. I know how much my blade can move, and how [it moves], and that’s what I do. The new controls do not worry me because I have been used to them since I was a boy - playing video games and working computers in school. I can see why somebody who has spent years hitting and pulling levers hard and using real muscle power to move controls could have a problem with the sensitivity of today’s buttons and switches. But it’s really no different from my pickup. Drivers don’t need to move the wheels with their own power, and the softer controls help the accuracy." Excellence in maneuverability is something that all operators have requested, and it has received close attention from designers at Case, New Holland, Deere, Caterpillar, Liebherr, Komatsu, Hyundai, Daewoo, and Hitachi. Several dozer drivers admitted that spinning the tracks has always been annoying, even embarrassing. When you put that blade into the earth, you don’t always know what to expect, but experienced operators claim they can sense how hard to push and when to withdraw and rethink their approach. "Our PowerTurn feature delivers maximum power to both tracks when turning, and it’s standard on all the H Series models," points out Schaefer. "That helps the operator to keep the blade full throughout a turn, without spinning the tracks." For the top of the line in the G Series-the 1150G-there are two track gauges available. The track rollers and carrier rollers are permanently sealed and lubricated, while drum-type idlers seal out abrasives and maximize undercarriage life. When one track goes over an obstruction, the Case equalizer beam suspension keeps the other track on the ground. To answer another demand from users, the H Series dozers offer a choice of three track styles: LT, a long track with a narrow width, easy to maneuver and transport; WT, a wider track to handle a wider blade for finish grading; and LGP, with low ground pressure where flotation is important to the successful completion of the job. Possibly the most important part of the dozer is the undercarriage. "The Case H Series are built with heavy-duty pins, bushings, links and rollers for long-term track life and machine performance," notes Schaefer. Several owners and operators mentioned that, even if the controls had become easy and the engineering sophisticated, the heart of the machine is its undercarriage. "It must be tough enough to take the abuse I give it," states operator Wes Williams. "I’ve used Case, Caterpillar, and Deere in different sizes, and they have all done me proud. If my production is good-and it is-it’s partly because the undercarriages are so tough." The other part, of course, is due to Williams’ expertise.
Not having to stop frequently keeps machine and operator progressing smoothly and productively. This success is often achieved, say users, when functions such as repositioning the blade’s approach to the ground can be completed "on the fly." The H-Series crawler dozers from John Deere offer a counterrotation usable at any speed and helpful for overcoming corner-loaded side drafts and for fast repositioning of the blade on the go. The operator need not shift into neutral to avoid stalling or limit the machine’s use to good ground conditions. On the Deere H-Series dozers, the operator sets the ground-speed lever to the maximum desired speed, and as loads change, the drive train responds by powering up and down. On level ground or a 2:1 slope, the driver does not need to cross-clutch or ride a brake, because the machine will not freewheel (as a dozer equipped with a torque converter might do). Among the features that Deere highlights for the H-Series dozers are the six-roller undercarriages designed to provide solid stability on slopes, ground-gripping tension, and balanced blade work. Cross-clutching and riding the brake used to be tricks that an operator could use to keep the work going, but they are further examples of what has been changed in new designs. The tracks on three of New Holland’s dozers can also counterrotate. Recommended for precision work and grading, the DC70, DC80, and DC100 are smaller models designed to give low operating costs and easy servicing. Low-ground-pressure versions of dozers offer superior flotation for work on weaker ground. Among several others in New Holland’s range of dozers are the DC150 and DC180, where the engine is matched to a torque converter and a powershift transmission with an automatic kickdown and automatic shifting to speed the loading and return cycles. Among options are a three-shank ripper, a rear hydraulic function for a winch, and a rear power-takeoff provision. Hyundai Construction Equipment offers the H70 for smaller dozing work, with 72 fly-wheel hp. This dozer, similar to ones from other manufacturers, is available in a low-ground-pressure version. It can reach up to 7.3 mph in forward and 7.4 mph in reverse. The rated operating capacity of this Hyundai model is 15,540 lb., with a blade capacity of 1.81 yd.3 and a maximum drawbar pull of 27,780 lb. "Knowing the capacities of a dozer is important," emphasizes operator Larry Holton. "I will try to use everything as much as it allows, but I have also seen the results of trying to exceed capacities. It’s not only unsafe, it can cost the boss thousands of dollars in repairs. And it would probably cost me my job." The advantages of hydrostatic drive have been acclaimed by users everywhere and include the fact that the diesel engine is never overloaded. All of Liebherr’s crawler dozers have hydrostatic drive to allow the operator to maneuver them with both tracks powered and without shifting gears. Liebherr dozers require little room for turning, and they can counterrotate on the spot. A joystick lever controls all driving and steering functions. For Liebherr’s PR 752 Litronic machine, there is a selection of blades available: the semi U-blade, the U-blade, and the mechanical tilt blade. A single-shank and three-shank ripper with a parallelogram configuration, as well as a rope winch and a trailer drawbar, are also available for rear mounting. Additionally, there are different blades for different materials to be dozed, such as those at landfills, mines, or land-clearing operations.
"They say that bad workmen blame their tools," says Art Kreutzer, who’s been running a dozer for more than 10 years. "But some of the changes made by manufacturers must be the result of some good workmen asking for better tools. Cat’s larger dozers have what’s called an elevated sprocket design, and it sounds like nothing, doesn’t it? But it has raised the final drives and power-train components so they don’t get stuck in the material. That has to help." Caterpillar has at least 45 dozer models available, with net power from 70 to 850 hp (the latter being the D11R with a tank refill capacity of 425 gal. to keep you going). The electrohydraulic dozer and ripper controls require little effort to use and are comfortable for the operator, with no mechanical linkages. For further ease of operation, the D11R has Automated Blade Assist, which is a semiautomatic dozer control function designed to increase efficiency and reduce operator workload by automating some of the more common blade functions. One of the problems with practical moving from place to place can be the tracks themselves. Dozer operators are well aware of the dangers of running steel tracks on paths and roads. "Sometimes we have had to load the dozer on a trailer just to take it a hundred yards," recalls one operator. "There are all kinds of regulations about taking these machines on city streets," says another. "And all those delays hurt our productivity." Komatsu is one manufacturer who has addressed that problem with its D21A-7 compact dozer. It has rubber tracks (in a 12-in. size for normal work or 20 in. for sandy, swampy, or slope applications), which means that it requires no special handling to move over concrete or asphalt surfaces and is less noisy when traveling. The rubber is overlaid on a steel base, and a track retention system prevents the rubber track from walking off the undercarriage. Komatsu makes some huge dozers, such as the D575A-2D with its 858 kW of power and a blade capacity of 90 yd.3, but its D155Ax-5 comes at the lower end of the range. "It includes many of the features found throughout the entire Komatsu dozer line," points out Ed Warner, Komatsu’s United States crawler dozer product manager. "It has a hydrostatic steering system, dual hydraulic pump system, resilient equalized undercarriage, proportional pressure controls, and human-first engineering principles." Komatsu also offers an INPAT blade, which can be adjusted in six directions, making it especially practical for leveling as well as for normal dozing. As they may be used for only part of an extended construction project, dozers are machines that rental yards have found profitable. Some of today’s smaller models might seem especially appealing to a contractor whose general work does not justify the expense of purchase. If anything, the smallest dozers require the greatest accuracy because they often work close to buildings, and even a small dozer will try to move anything that gets in the way of its blade. In terms of safety and liability - not just good productivity - it is critical to make sure the operator knows how to use the features of a rented dozer. Two or three rental companies reported that the instructions for running their machines are clearly visible inside the cabs and that they usually run through the basics with prospective renters. After talking to so many operators about the skills required for good dozing, those kinds of instructions seemed somehow inadequate.
Paul Hull is a frequent contributor to Grading & Excavation Contractor.
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