Komatsu PC138-8 Short Tail Swing Excavator Overview

[MikePhua]

Komatsu’s Dash-8 Series and Compact Innovation
Komatsu, founded in 1921 in Japan, has long been a global leader in construction and mining equipment. The Dash-8 series marked a significant leap in excavator design, emphasizing fuel efficiency, operator comfort, and electronic control integration. Among this lineup, the PC138-8 short tail swing excavator was developed to meet the growing demand for compact machines capable of operating in confined urban and roadside environments without sacrificing power or reach. By 2007, Komatsu had already sold tens of thousands of Dash-8 units globally, with the PC138-8 gaining traction in North America, Europe, and Asia.
Terminology Annotation

• Short Tail Swing: A design where the rear counterweight of the excavator does not extend far beyond the tracks, allowing safer operation near walls or traffic.
  
• Hydraulic Excavator: A machine that uses pressurized fluid to power boom, arm, and bucket movements for digging and lifting.
  
• Dash-8: Komatsu’s eighth-generation excavator platform, featuring improved electronics and emissions compliance.
  

Design Features and Performance Metrics
The PC138-8 is engineered for versatility and precision. Key specifications include:

• Operating weight: Approximately 13,800 kg
  
• Engine: Komatsu SAA4D95LE-5 turbocharged diesel
  
• Net horsepower: Around 93 HP (69 kW)
  
• Bucket capacity: 0.4 to 0.6 cubic meters
  
• Tail swing radius: Under 1.5 meters
  
• Hydraulic system: Closed-center load sensing with variable displacement pumps
  

This configuration allows the machine to work efficiently in tight quarters while maintaining breakout force and lift capacity comparable to larger models.
Urban Applications and Field Anecdotes
Short tail swing excavators like the PC138-8 are ideal for:

• Roadside trenching and utility installation
  
• Urban demolition and foundation work
  
• Bridge maintenance and tunnel excavation
  
• Landscaping and municipal projects
  

In Montreal, a contractor used the PC138-8 to excavate sewer lines along narrow alleyways without disrupting traffic. The machine’s compact tail and responsive hydraulics allowed precise digging between buildings, reducing project time by 30%.
Terminology Annotation

• Breakout Force: The maximum force the bucket can exert when digging, critical for penetrating hard soil or asphalt.
  
• Closed-Center Hydraulic System: A system where fluid flow is regulated based on demand, improving efficiency and reducing heat.
  

Operator Comfort and Control Enhancements
Komatsu’s Dash-8 cabs are designed with ergonomics in mind. Features include:

• Adjustable suspension seat with lumbar support
  
• Low-effort joystick controls with proportional auxiliary flow
  
• Large LCD monitor displaying fuel usage, maintenance alerts, and diagnostics
  
• Climate control and noise insulation for reduced fatigue
  

Operators report reduced strain during long shifts and improved visibility thanks to the cab’s wide glass panels and low-profile dashboard.
Fuel Efficiency and Emissions Compliance
The PC138-8 meets Tier 3 emissions standards through:

• Electronic engine management
  
• Optimized fuel injection timing
  
• Auto idle shutdown and economy modes
  

Fuel consumption averages 8–10 liters per hour under mixed duty cycles, making it competitive in its class. In 2008, a fleet in Germany replaced older units with PC138-8s and reported a 15% reduction in fuel costs over the first year.
Maintenance and Reliability
Routine service is simplified through:

• Ground-level access to filters and fluid ports
  
• Swing-out panels for radiator and hydraulic cooler cleaning
  
• Onboard diagnostics for early fault detection
  
• Extended service intervals for engine oil and hydraulic fluid
  

Komatsu’s KOMTRAX telematics system allows remote monitoring of machine health, location, and usage patterns, helping fleet managers optimize uptime and schedule preventive maintenance.
Terminology Annotation

• KOMTRAX: Komatsu’s proprietary remote monitoring system that tracks machine performance and alerts users to maintenance needs.
  
• Telematics: The integration of telecommunications and informatics to monitor and manage equipment remotely.
  

Recommendations for Buyers and Operators
For contractors considering the PC138-8:

• Ensure job sites require compact tail swing to justify the premium
  
• Train operators on economy modes and hydraulic fine control
  
• Use genuine Komatsu filters and fluids to maintain warranty
  
• Monitor swing bearing and undercarriage wear in high-cycle environments
  

The machine performs best in urban and utility settings where maneuverability and precision outweigh brute force.
Conclusion
The Komatsu PC138-8 short tail swing excavator represents a thoughtful blend of compact design, hydraulic finesse, and operator-centric engineering. Its ability to work in restricted spaces without compromising performance makes it a valuable asset for modern infrastructure projects. With proper maintenance and skilled operation, the PC138-8 delivers long-term reliability and efficiency across a wide range of applications.