Komatsu short-tail low-emission Dash 11 excavators
Komatsu short-tail low-emission Dash 11 excavators lower fuel consumption, improve operating efficiency
Komatsu has launched two new short-tail excavators, the 14-tonne PC138US-11 and the 23.7 tonne PC228US-11, powered by lowemission Tier 4 engines, and featuring advanced electronic engine and hydraulic control systems. The PC138US-11 has a Komatsu SAA4D95LE-7 engine is rated at 73kW, while the PC228US-11 is powered by a Komatsu SAA6D107E-3 engine rated at 123kW. The PC228 is also available in a LC version with extended undercarriage.
Both excavators comply with US Tier 4 Final emissions regulations, reducing NOx and PM emissions by 90 per cent compared with their Dash 8 predecessors. They also incorporate new Komatsu fuel-saving technology, including auto deceleration to low idle if the machine idles for more than a few seconds, auto idle shutdown, and enhancements to the main hydraulic control valve to reduce hydraulic losses.
“The Dash 11 excavators now feature improved matching between the engine and the hydraulic pumps, allowing the engine to operate at the most efficient speed and save fuel,” Komatsu national business manager – construction Amber Rickard says. “Higher pump displacement allows the machines to achieve higher flow outputs at lower engine rpm.
“Known as Low Speed Matching, this system also provides better pick-up and response to hydraulic flow demand, as well as providing fuel savings in low, medium, and high duty cycles.
“Both machines also feature our Variable
Speed Matching control system, which matches engine speed to pump delivery across both high and low duty cycles, and reduces fuel consumption by lowering engine speed during low flow operations.”
Six working modes further match engine and hydraulic power output to specific applications, and include power, economy, fine operations/ lifting, breaker, attachment power and attachment economy modes. Both models also incorporate a viscous fan clutch system that ensures optimal cooling fan speed, reduces fuel consumption and contributes to lower noise levels.
The short-tail swing radius on both machines allow them to work in far more confined areas than a conventional machine. The PC138US-11 has a tail-swing radius of 1480mm and the PC228US-11 has a tail-swing radius of 1785 mm.
“They are equipped with a contoured cab design and convex sliding door that allow the cab to swing within the same radius as the counterweight, making them ideal for applications such as roadworks and urban or underground environments,” Rickard says.
Despite their compact design, both excavators feature full-size integrated ROPS cabs with a wide front view of the work area.
“The cabs also feature a new high back, air suspension operator seat with lumbar support and more robust slide rails for improved reliability,” she says.
Maintainability of these machines has been further improved, with left- and right-hand service doors allow access to all major maintenance points from ground level – simplifying regular maintenance checks. Both models are also fitted with fan belt auto tensioner, eliminating the need for fan belt adjustments.