Photo by Komatsu
Pictured is Komatsu’s tight tail PC78US-11 Excavator

Komatsu’s PC78US-11 Boom Design Designed for Tight Spaces

Sept. 14, 2021
The conventional boom design has a greater raising angle to reduce front bucket swing radius.

Posted by Brooke Just

For work on roadways, bridges, urban areas, or anywhere space is limited, contractors need an excavator designed for confined spaces. Komatsu’s tight tail PC78US-11 provides a combination of performance and versatility in a compact and easy-to-transport package.  

With standard high flow auxiliary hydraulics and proportional joysticks that offer job versatility, the 67.7 HP (50.6 kW)  PC78US-11 provides precise attachment control. Its standard grading blade with new moldboard profile improves backfilling and light grading efficiency. The conventional boom design has a greater raising angle to reduce front bucket swing radius.

Its faster boom up/swing speed, combined with responsive quick arm speed, is designed to make excavating and leveling work more efficient with the PC78US-11. The six working modes allow operators to tailor the machine to the required tasks, whether for fuel savings or performance.

The new high-efficiency power package and viscous fan clutch on the PC78US-11 work to lower overall fuel consumption by up to 13 percent. Its catalytic system removes soot without a diesel particulate filter, lowering maintenance costs and cost of ownership.

Large service access doors and grouped service points with ground-level access make periodic maintenance accessible and efficient.

Operators work in a quiet, climate-controlled cab featuring an air suspension seat, Bluetooth radio, and high-resolution monitor with rearview camera. The sliding cab door of the PC78US-11 makes entry and exit easier in confined spaces and LED lights provide excellent vision at night.

For more details on the new PC78US-11 excavator, go to