D7E Cuts Fuel Costs

D7E Delivers 50% Fuel Savings for Arkansas Landfill

A Cat® D7E LGP Track-type Tractor used primarily to spread and compact waste on the working face at the Northeast Arkansas Solid Waste District Landfill burns about half as much fuel as the machine that previously did the work.

The D7E consumes approximately 40 gallons of fuel per day less than the machine that it replaced. “The other machine used about 80 gallons per day, and we were filling the fuel tank every day,” said Shay Robinson, Operations Manager of the 380-acre landfill located in Paragould, Ark.

At $3.50 per gallon of diesel fuel, the Northeast Arkansas Solid Waste District landfill is saving $140 in fuel costs every day the D7E works.

With a targeted service life of 20,000 hours, the D7E could reap more than $300,000 in fuel savings for the district.

The machine previously used for compaction on the working face burned more than eight gallons of fuel per hour. After 2,531 hours of operation, the D7E has consumed 10,656 gallons of fuel, which is an average of 4.2 gallons per hour, according to machine performance information provided by VisionLink®.

Monitoring Performance

The VisionLink monitoring system provides information such as hours, fuel usage and diagnostic codes that can be used by customers to effectively manage fleet usage, and monitor machine performance to schedule preventive maintenance and help avoid unanticipated downtime.

As the numbers prove, the D7E’s unique diesel-electric powertrain burns considerably less fuel than traditional systems. The electric generator, power inverter, and propulsion module in the electric drive system replace traditional mechanical components to improve power and efficiency.

At the Northeast Arkansas Solid Waste District Landfill, the D7E spreads waste primarily on the working face pile. At 62,886 pounds, the D7E is able to achieve targeted compaction density in fewer passes than the previous machine. “We are realizing much better compaction than we did, probably twice as good,” Robinson said.

Each day, the four-county regional landfill processes approximately 300 tons of residential, commercial, construction and demolition waste.

The D7E was purchased in 2012 to replace a machine that cost $80,000 annually to operate because of high fuel consumption and high repair costs. “It spent more time in the service bay than the landfill,” Robinson said. Because of excessive downtime, the unit was sold sooner than planned. “Generally, we try to keep machines five years or 10,000 hours,” said Robinson.

With the D7E’s fuel savings, excellent compaction rates, and outstanding uptime, the machine may be working at the landfill for many years. “We’ve had zero downtime in the 14 months that we’ve owned the machine,” said Robinson. “And this is a very hard environment on machines.”

Difficult Conditions

Uptime is extremely important at any landfill. “If it’s raining, snowing—whatever the conditions—we’re still taking in waste,” Robinson said. “We need a machine that can work in difficult conditions—that’s the D7E.”

Operators also appreciate the D7E’s smooth ride and excellent blade control. “People start working on the machine, and they don’t want to get off,” Robinson said.

“It’s perfectly ergonomic,” said Roy Peters, machine operator. “It’s very comfortable.”

Another feature that benefits operators, the infinitely variable speed control, enables the machine’s speed to be set at each individual’s preference to maximize production.

To help keep a pair of D6R Track-type Tractors and the D7E in top shape, Riggs Cat technicians complete all warranty and repair work. “I can call the service manager, and have a technician here the same day,” Robinson said.

That is how the Northeast Arkansas Solid Waste District Landfill keeps pace with the ever-flowing waste stream.