Yancey Bros. Co. recently hosted two demos of the new Cat D7E electric drive dozer. More than 30 contractors turned out at Yancey’s Macon, Ga., location and more than 45 came to the Dacula, Ga., location to see the machine in action and try it for themselves.
Bob Powers, a professional demonstrator who works with the marketing group as an application consultant for Caterpillar in East Peoria, Ill., has been traveling the country displaying the features of the new D7E. A true showman, Powers begins by taking the D7E to the top of a very steep pile of dirt and “teeter-tottering” for a few moments. As Powers takes the machine down the hill and approaches the crowd, he positions the D7E with an obvious view of the single cylinder in line with the exhaust, air intake and the center post cab. Then he slowly turns the machine, showing that he can be seen from head to toe through the window of the cab, which means that, in turn, the visibility from the inside out is just as impressive.
Powers said, “At this point, I turn the machine around 180 degrees, put the ripper down and raise the machine up to show the steering capability and counter rotation, which we have in our existing tractors. Then I put it in forward gear and show how we can do a lock track pivot turn, which basically allows you to lock the inside track and turn on a dime. It’s the only diff steer tractor in the industry that is able to do that.”
Powers continued the demonstration by performing ripping and dozing passes and by making quick work of backfills. By taking the D7E through a cone slalom course Powers demonstrated the machine’s enhanced maneuverability and steering improvements over the D7R. Powers finished with a walk around of the machine and then opened the floor for the operators to ask questions and get some stick time.
When asked about what comments he receives from first-time operators, Powers said that many rave about the visibility. Others give very high marks for its performance and say they can’t believe how agile and nimble it is and many compare it to the agility of the D6 with the power of a D8, with extreme ease of operation. On this machine, Powers stated, “you set top desired track speed and the power train manages itself according to the load.”
“One interesting comment I received when I did a demo in West Texas where it was 105 degrees out,” Powers mentioned. “An operator got out of the cab and commented that the air conditioner got so cold in the cab you could hang beef.”
Powers further elaborated on the air conditioning system.
“The cold a/c is one thing we talk about with this tractor because we have a self-sustained HVAC unit mounted on the back of the cab, which is all self-contained. The heater core is up there, the a/c compressor [which is electrically driven], the evaporator and condenser. Basically it’s much like a window unit in your house. That’s how our supplier brings it to us. We just bolt it on, hook the 320 volt a/c cable up to it, heater core, hoses and it’s ready to go. It keeps the noise and all the components outside and gets rid of one more belt [parasite] on the engine, which helps to maximize fuel efficiency.”
The lack of belts and other energy drains, or what Powers calls parasites, on the new D7E is a big change from former models.
“Inside the engine compartment you’ll see no belts or pulleys so there are fewer ’parasites’ robbing fuel economy and there are no belts to replace. There’s no a/c compressor, no alternator and no water pump taking power from the engine. The fan is not driven by the engine either — it is driven hydraulically, while the a/c compressor and the water pump are driven electrically and this allows us to actually get by with a smaller engine. The D7E has five less horsepower than its predecessor because more of that power is now being transferred into productive work. Of course we get the efficiency of electrical vs. mechanical transfer of power from the engine down to the ground. All the hydraulic pumps are mounted on the rear of the engine and are still gear driven, mechanically driven, but they are variable displacement and thus produce flow in proportion to demand. So if there’s no demand for them, they take only minimal power from the engine.”
Customer reaction to the new D7E was overwhelmingly positive.
“We have strong interest from customers around the state. Following the event in Gwinnett we sent the D7E south to Savannah and in total over 150 customers saw the machine. We believe the D7E will be an important machine for Georgia, and we look forward to delivering the initial units in 2010,” stated Jim Stephenson, president and chief executive officer of Yancey Bros. Co. CEG
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