ForConstructionPros.com

In the 1950s when the first hydraulic excavators were introduced, the machines were all equipped with rubber-tire undercarriages. Such configurations continue to be highly popular in Europe today.

In North America, however, wheel excavators have yet to achieve firm footing. "They are still considered a niche product," says Bill Metzgar, product training coordinator, Doosan Infracore America. Popular among county and state governments, these machines are just starting to see more use in road work and scrap handling operations, he adds.

Chad Cremeens, wheel excavator marketing for NACD and LACD, Caterpillar Inc., agrees that wheel excavators are still largely viewed as niche machines. "But for many, it's a niche machine they cannot live without," he says. "For years, the wheel excavator has been an essential part of governmental fleets (municipalities, highway departments, etc.). Recently, private contractors have started to realize the value, as well."

Instant mobility
Archer Western Contractors, a division of The Walsh Group, is one such company. This general contracting, construction management and design-build firm handles building, civil and transportation projects throughout the country.

Its Phoenix Regional Office is nearing completion of one the segments of the Valley Metro Rail Line, a light rail system that will run through the heart of downtown Phoenix. Four wheel excavators - two Caterpillar M318s and two M322s - have been on the job almost since its inception roughly 26 months ago. Mobility is the primary reason they were brought in.