Komatsu introduces low-emission Dash 11 short-tail excavators

Komatsu has unveiled two new short-tail excavators – the 14-tonne PC138US-11 and the 23.7-tonne PC228US-11 ideal for work in confined areas.

The PC138US-11 has a Komatsu SAA4D95LE-7 engine rated at 73 kW, while the PC228US-11 is powered by a Komatsu SAA6D107E-3 engine rated at 123 kW. The PC228 is also available in a LC version with extended undercarriage.

According to Komatsu, 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.

The engines incorporate new Komatsu fuel-saving technology such as 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,” said Komatsu’s National Business Manager for Construction, Amber Rickard.

“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.”

As Komatsu designs and manufactures all major components in-house, its systems are designed to work together to optimise machine performance for maximum production and minimal fuel consumption.

“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,” Rickard said.

Both models feature six working modes -  power, economy, fine operations/lifting, breaker, attachment power and attachment economy modes to further match engine and hydraulic power output to specific applications.

They also incorporate a viscous fan clutch system that ensures optimal cooling fan speed that 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 1785mm.

“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 road works and urban or underground environments,” Rickard said.

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,” Rickard added.

A large in-cab monitor display allows constant monitoring and reporting of a whole range of operating parameters, and the physical layout of key components has also been optimised.

Left and right-hand service doors allow access to all major maintenance points from ground level for simplified regular maintenance checks.

Komatsu’s KOMTRAX telematics remote monitoring system is also available on both PC138US-11 and PC228US-11 to give owners and fleet managers full visibility of the machines’ whereabouts, performance and operational status.

Brief specs of Komatsu’s new short-tail Dash 11 excavators:

PC138US-11
Operating weight: 14,000kg
Power: 73kW
Bucket size: 0.21- 0.53 cubic-metres
Max dig depth: 5480mm
Bucket breakout: 8300kgf
Arm breakout: 6200kgf

PC228US-11
Operating weight: 23,750kg
Power: 123kW
Bucket size: 0.39-0.97 cubic metres
Max dig depth: 6620mm
Bucket breakout: 13,500kgf
Arm breakout: 10,500kgf

PC228USLC-11
Operating weight: 24,120kg
Power: 123kW
Bucket size: 0.39-0.97 cubic metres
Max dig depth: 6620mm
Bucket breakout: 13,500kgf
Arm breakout: 10,500kgf