Colorado’s Crossfire LLC finds electric-drive Caterpillar dozers make the grade for reducing expenses and boosting an eco-friendly reputation.

As Ezra Lee considered adding a new bulldozer to the fleet of Caterpillar equipment owned by his company, Crossfire LLC, he wanted a machine that could deliver four key benefits: decreased fuel costs, eco-friendly operation, lower maintenance expenses, and a "green" marketing angle to attract and retain environmentally sensitive customers.

That might sound like a tall order. But with the purchase of two electric-powered Caterpillar D7E bulldozers, the owner of the Ignacio, Colo.-based provider of oil and gas field support services can sum up the results of his search in two words: mission accomplished.

After testing a prototype of the D7E during most of 2010, Lee was so pleased with the results that the company bought the model. Last February, the company bought another one. The price tag was about $600,000 each, which is more than the cost of a conventional bulldozer. But the benefits the machines bring to the table made it an easy decision, Lee says.

"With the fuel savings, the marketing advantages and the decreased maintenance costs, it was a no-brainer," he says. "I expect fuel costs will continue to rise, which means that five years down the road we should see that premium price we paid carry through on resale, when compared to a conventional diesel dozer. The machines effectively pay for the premium."


Except for a Caterpillar C9.3 235 hp diesel engine that powers a three-phase, 480-volt electric generator, everything on the D7E runs on AC electrical current. The generator powers everything from the air conditioning to the final drive motors on the tracks to the hydraulic pump that lifts and lowers the blade. That results in a substantial decrease in fuel use — up to 25 percent, Lee notes.

"Compared to a conventional Caterpillar D7R diesel bulldozer, that saves us about $10 an hour per machine in gas, or $100 a day in a typical 10-hour workday," he explains. "That's a significant savings over the life of a dozer."

In addition, the D7E cuts maintenance costs by about 75 percent by eliminating service intervals required by items such as a hydraulic transmission and other components. Instead of a hydraulic transmission, the dozer relies on an infinitely variable-frequency drive; there are no gears to shift — just a dial an operator turns to boost or reduce speed. Moreover, the dozers require no engine belts, engine-mounted compressors, alternators or clutches. Fewer parts further reduce the potential for costly repairs and maintenance.

"We went from five service intervals on the hydraulics of the machine down to one (for the engine)," Lee says. "So along with the fuel savings, we're pushing $30,000 a year per dozer in savings that goes straight to our bottom line."

Lee admits he was initially concerned whether an electric dozer would be powerful enough to perform as well as a diesel-powered unit.

"But the D7E gets better torque to the ground than a conventional hydraulic torque converter," he says. "In terms of productivity, we rate the D7E's just under a D8-size dozer. The D7E is lighter, but has a lot of pushing capacity — maybe just a 10 percent reduction compared to a D8, in terms of pushing dirt."


The D7E also provides environmental benefits. It's significantly quieter than a conventional dozer, which is important if Crossfire deals with U.S.
Department of Wildlife noise-pollution standards when working on projects sited on federally owned land. It also enables the company to easily meet Tier IV federal emission standards without sacrificing power and performance, Lee says.

Also, the electric dozers — which Crossfire uses primarily for building access roads to well sites and site reclamation — don't carry 95 gallons of hydraulic oil found in conventional dozers, which pose an environmental risk if a hose breaks.

"There's no potential for cleanup costs, which is a strong selling point for our customers," Lee says.

In addition, the electric dozers provide Crossfire with a "green" marketing angle that makes it more attractive to customers, both old and new.

"We've had major oil companies award us contracts just because we have the electric dozers," Lee says. "It allows them, in turn, to tell the federal agencies they work with that they use contractors with electric technology. I'm not sure how you quantify that value, but it helps us maintain and grow current relationships with integrated gas and oil clients because they want to do business with eco-conscious customers."

Lee says he's so happy with the D7Es' performance that Crossfire will never buy another conventional dozer.

"The dozers are key pieces to our company's strategy moving forward ... and provide significant cost savings to our overall business," Lee notes. "In fact, I hope Caterpillar comes out with the same (electric) design for other sizes of dozers, track hoes and the like." GOMC

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