When the EPA’s Tier 3 engine emissions requirements came due this year, Komatsu didn’t just drop in new powerplants and tweak the cup holders. It used the opportunity to engineer a new generation of machines, primarily dozers, loaders and excavators, that are more productive, use less fuel and keep operators safer and more comfortable.
Of the 43 new machines recently introduced we selected three – the D155AX-6 SigmaDozer, the PC220LC-8 excavator and the WA600-6 wheel loader – as being most representative of the new technology, and we visited Komatsu’s testing and training facility in Cartersville, Georgia, to try them out.
There we met with three of the company’s product managers and brought along Tony Rye, a veteran equipment technician, to run the machines and give us his feedback. Here’s an in-depth look at what we discovered.
D155AX-6 SIGMADOZER
QUICK SPECS
354 horsepower
87,100 pounds
12.3 cubic-yard blade capacity
Save for the blade out front, there’s nothing particularly new about the components used in Komatsu’s SigmaDozer design. Bogies, pivot shafts, torque converters and differential-type steering mechanisms can be found in other types of machines, usually much smaller machines. But the combination of these components, the fact that they’re propelling a 40-ton bulldozer and the way the various systems use a computer “black box” or electronic control module to communicate with each other make for an altogether new and impressive experience from the operator’s seat.
The feeling is akin to stepping out of a rigid frame truck and into a sports car – except this sports car moves mountains. The ride is ultra-smooth (for a dozer) and the tracks stay firmly planted on the ground, boosting efficiency, productivity and fuel savings.
In operating the SigmaDozer, Rye used it to cut down material off a highwall and push it toward an excavator that was loading trucks. The soil coughed up plenty of large rocks, which would normally create a jarring ride, but in this instance proved to be a good test of the undercarriage and suspension. Despite the rocks, there was little lurching and shock transmitted to the cab. “I don’t know of any dozer I’ve operated that was as comfortable,” Rye says. “I didn’t have to strain against the seat belt to keep from coming out of the seat. If I had to make a living in a dozer, this one would be a comfortable choice,” he says.
