Mike Evans and Kevin “Zip” Ackert handle most of the dozer-operator training for Local 150’s (International Union of Operating Engineers) Apprenticeship and Skill Improvement Program headquartered at the Local’s expansive 300-acre training facility near Wilmington, Ill. So, when Case Construction Equipment was gracious enough to lend Construction Equipment a new 2050M—the largest crawler dozer the company has ever marketed in North America—Evans and Ackert were naturals for running the new model and offering their candid opinions about its design and performance.
From our perspective, the 2050M takes a big step ahead of its 1850K predecessor in overall design: the new model has 30 more horsepower; a dual-path hydrostatic drive system that replaces the 1850K’s power-shift transmission and differential steering system; new cooling package; redesigned mainframe; redesigned blade supports; refined undercarriage; new cab; redesigned implement hydraulics with a multifunction main valve that replaces the 1850K’s stacked valve; plus, the 2050M can leave the factory ready to accept any of the major 3D grade-control systems—Trimble, Topcon, or Leica.
In addition, the company has chosen to bring the 2050M’s 214-net horsepower Case (Fiat Power Train) engine into Tier 4-Interim compliance using only an SCR (selective catalytic reduction) system. The SCR system controls nitrogen-oxide (NOx) emissions by injecting diesel exhaust fluid (urea) into the post-turbocharger
exhaust stream in the presence of a catalyst.
This emissions-control strategy, said Case’s David Pariso, product sales training manager, and Neil Detra, product specialist, who were on site for the 2050M evaluation, allows the engine to run in a “lean” fuel condition that promotes high combustion temperatures, which are instrumental for in-cylinder control of particulate matter (PM), the other major pollutant on the EPA’s hit list. Case says that the 2050M’s engine, while delivering 14 percent more power than that in 1850K, also provides fuel savings on the order of 10 percent.
The working ends
The 2050M arrived at the ASIP training facility with a 7.3-cubic yard, 160-inch-wide, “six-way” PAT (power angle/tilt) blade with manual pitch adjustment. At the back was three-shank, parallel ripper, having a cut width of 75 inches and a maximum penetration of 26 inches.
The PAT blade on our 2050M is available in a foldable version for those with transport-width issues, or, as a narrower, 142-inch version. If application warrants, the 2050M accepts a 7.3-cubic yard semi-U and either of two straight blades at 131 and 154 inches. Blades are used in specific combination with the 2050M’s four undercarriage configurations—long-track (LT), extra-long-track (XLT), wide-track (WT), and low-ground-pressure (LGP).
According to Pariso, the selection of blade and undercarriage configurations—coupled with the new tractor’s added power and operating weight (44,500 to nearly 49,000 pounds)—allow the 2050M to work competently in both grading and production-dozing applications.
To that end, and to accommodate the 2050M’s impressive pushing power (it has nearly 25 percent more drawbar pull than the 1850K), Case developed a new heavy-duty, box-section C-frame and mounting structures for the PAT blades, as well as heavier push beams for the semi-U and straight blades. The under-tractor C-frame isolates the blade from track frame oscillation and side forces (promoting a stable grading platform), and Case’s Equistatic system for mounting semi-U and straight blades is designed to reduce effort on the push beams (trunnion-mounted to the track frames) and to increase tilting capability.
To further tailor the 2050M to grading applications, operators can select from three levels of hydraulic response to adjust blade speed to their liking. The setting is selected via the 2050M’s Advanced Instrument Cluster (AIC). If the machine is used only occasionally for grading, then the “grading” button on the right joystick allows a quick, temporary, 40-percent reduction in blade speed.
Also on the right joystick are a rocker switch that angles the blade and a blade-shake button, which when held depressed, causes the PAT blade’s tilt cylinder to cycle rapidly and shed material sticking to the blade.
Grading and ripping
Ackert used the 2050M primarily to do cross-slope grading and for ripping on a berm constructed of loosely compacted clay. After he had spent considerable time on the new tractor, we solicited his impressions.
“Overall, it’s a nice machine. It was very sure-footed on the slope—didn’t seem to matter what attitude I’d place it in, it remained stable. It’s a very well balanced tractor—plenty of power. It handled the ripper fine, although the ripper is on the small side—I’d like to try it with a semi-U.”
Ackert also took note of the 2050M’s steering controllability, which includes counter-rotation and three levels of steering sensitivity (smooth, moderate, aggressive) selected via the AIC.
“With hydrostatic drive, turns are easy and smooth, even with the blade loaded,” said Ackert. “And the counter-rotate a nice feature; I used it at the end of the push. I didn’t notice which of the three steering speeds was selected, but steering response was positive and comfortable.”
The 2050M further allows operators to tailor machine performance to the situation or to their liking by providing a choice of three forward/reverse shuttle ratios, allowing the tractor to resume a pre-selected speed (forward or reverse) after a directional shift. Ackert noted that the setting for the 2050M on site was 13/15, and he said that the ability to adjust the ratio is a valuable feature. (The 2050M has 15 speed increments selected via buttons in the left joystick.)
“If a contractor is concerned about undercarriage wear, for example,” said Ackert, “he could easily limit reverse speed.”
Yet another operator-selected control feature Ackert liked was a foot pedal that can be programmed to react either as a hydrostatic brake to proportionally reduce ground speed, or as a conventional decelerator to reduce both ground speed and engine speed.
“I learned to run dozers using a decelerator,” said Ackert, “so I like this feature—but I can run either way.”
Evans, on the other hand, used the 2050M for heavy dozing and ripping in wet, tacky, black soil.
“The PAT blade isn’t the optimum choice for hogging dirt, especially one that size,” said Evans, “but I basically wanted to dig a hole just to see how the tractor would perform. It has power, no question about that; it slowed under heavy load, but the tracks never stopped.”
Detra explained that the 2050M’s hydrostatic drive system continually senses the load and adjusts the system’s hydraulic pumps to deliver the optimum torque/speed combination in a given operating situation.
“I’d been running in speed 13, but shifted down to 11 in the heavy going,” said Evans. “The tractor seemed to be very constant in how it reacted.”
Evans said he found the 2050M’s implement hydraulic system very responsive—“not too fast,” he said—(although we didn’t think to take note of which of the three blade-speed settings had been programmed at the factory).
“And the blade-shake feature—I liked it,” said Evans. “It’s the first time I’d run a machine with that capability, and it seemed to work. I also found the control for angling the blade easy to use, even though I initially thought it would be a problem. Seemed to me that the switch should move side-to-side to match blade movement, but once you’re in the seat and operating, the way the switch is oriented is really not a problem.”
(Pariso explained that Case engineers determined that mounting the switch vertically, so that operator pushes at the top or bottom, made it ergonomically easier to use.)
Feature pros and cons
Although Evans and Ackert gave the 2050M high marks for power, controllability, stability, and useful operator features, they agreed that the new dozer came up a bit short on visibility—at least configured as was the Wilmington tractor, with an optional above-hood pre-cleaner and forestry sweeps.
“I’d like to have better visibility both out the front and to the ripper,” said Ackert. “In fairness, though, I realize that the pre-cleaner and the sweeps are options, and without them, the view would open up. But I did have a difficult time seeing the ripper—it was more a matter of feeling what it was doing rather than seeing what it was doing.”
Evans concurred: “Visibility across the front was obscured by the exhaust stack, the sweeps, and the air cleaner, but out the side windows, you could certainly see the blade well enough. Out the back, it’s difficult to see rear-mounted equipment, because the seat back is high and because you’re seated looking straight ahead—there’s no angle to the seat’s position. A couple times when I tried raising up in the seat to look out the back, I got an operator-presence warning.”
When we asked Case about the visibility issues, the company said that the tractor at Wilmington had been configured with the sweeps and pre-cleaner for a testing cycle with a customer involved in the aggregates market. Contractors in road-construction, site-development, and general-construction applications typically would not specify these options, said Case, and forward visibility would be thus unimpaired.
Concerning visibility to the ripper, Case reminded us that a mirror positioned at the right rear corner of the cab, when properly adjusted, is designed to give the operator a clear view of rear-mounted equipment with an over-the-shoulder glance that involves minimal body movement. In fairness to the 2050M’s overall excellent design, we missed that detail.
Evans also said that he found getting into the cab through the right door a bit awkward, because of the guard that extends at an angle from the doorframe and passes in front of the right (blade) joystick, a measure designed to prevent bumping the lever, which remains live until deactivated with a switch on the panel. (The guard is in lieu of conventional gates that block exit from the cab until lifted to deactivate hydraulics.) Evans did say, however, that entering the cab through the left door would probably be more typical for most operators, because the master switch is on that side.
Pariso explained also that the 2050M sets the parking brake if the operator leaves the seat, or if the hydraulic system is inactive for 30 seconds with the machine at low idle. Ackert thought this a good feature, because he said he’s seen distracted or inattentive operators climb down from a machine, maybe to consult with someone on the job site, without setting the brake.
Evans added that designing this safety feature to require a low-idle condition along with hydraulic inactivity was a good thought, because having to unlock the brake (with a switch on the panel) after every short interval of hydraulic inactivity, such as waiting momentarily for job-site traffic, would be tiresome.
Evans also had good words for the 2050M’s serviceability, noting the machine’s ground-level access to routine maintenance points, centralized grease zerks (for models using push beams and vertical lift cylinders), and, in particular, the step on the ripper (and on other rear-mounted equipment) that gives convenient access to fuel, diesel-exhaust-fluid, and hydraulic-oil fill points.