New Komatsu Combines Technical Refinement with Nimble Dimensions

By Walt Moore, Senior Editor | September 28, 2010

Komatsu's PC138USLC-8 hydraulic excavator has an operating-weight range from 31,107 to 32,568 pounds and uses a 92-horsepower (net) Komatsu diesel engine that is Tier-3-compliant and employs a common-rail, multi-stage-injection fuel system. The new excavator also uses a variable-capacity, piston-type hydraulic pump, which produces a flow of 64 gpm at a main-relief pressure of 5,050 psi in the implement circuit.

This power is packaged quite compactly, however, because the PC138USLC-8 has an upper-structure protrusion (over its 24-inch track shoes) at the rear of only 9.80 inches, according to Komatsu. In addition, the company has rounded the front corners of the new model's upper structure, a design element that reduces upper-structure protrusion at the left front corner to less than 12 inches, and protrusion at the right front corner to less than 4 inches. Overall width of the machine is 8.5 feet, and height to the top of the cab is 9.25 inches. Length of track-on-ground is 10.3 feet.

Complementing the unit's 15.1-foot boom are two available digging arms, a standard 8.17-foot version, and a long-reach 10.83-foot version. Maximum digging depths are 18.0 and 19.3 feet, respectively, or you can leave an 8-foot stretch of level trench at depths of 17.25 and 18.75 feet, respectively. A large selection of buckets is available, as well, ranging from 0.34 to 1.00 cubic yard. Maximum dumping heights for the two arms are 22.4 and 24.1 feet, respectively.

In the new cab, says Komatsu, the operator will be exposed to a low level of sound, about the "level of noise similar to that of a modern automobile." The quiet cab results from reducing noise at its source, coupled with such features as viscous cab mounting, sound-attenuating material around the main control valve, and a sound-attenuating partition between the cab and engine compartment. The air-conditioned cab (automatic controls allow precise regulation of temperature) is pressurized to resist dust intrusion, and a sliding convex door eases access.

A new 7-inch, thin-film-transistor, liquid-crystal-display monitor in the cab allows the operator to choose from five working modes: power, economy, lifting, breaker and attachment. Each mode is designed, says Komatsu, to match engine speed and pump speed with the application. At the right of the monitor is the "Eco-gauge," which is a vertical-bar indicator of how the operation of the machine is affecting fuel consumption. The monitor also serves as a full-color screen for images picked up by the standard rear-view camera.

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Basic Specifications
* with 24-inch shoes
Engine make/model Komatsu/SAA4D95LE-5
Displacement (liters) 3.26
Horsepower (net) 92 @ 2,000 rpm
Hydraulic Flow (gpm) 64
Main Pressure (psi) 5,050
Operating Weight (lb.) 31,504*