Choosing and Managing a Mixed Fleet of Excavators for Versatile Earthmoving

[MikePhua]

The Value of Owning Multiple Excavators Across Sizes and Brands
For contractors working across varied terrain and job scopes—from tight urban trenching to rural land clearing—owning a mixed fleet of excavators offers unmatched flexibility. Operators who manage multiple machines often find that pairing compact units with mid-size and full-size diggers allows them to respond to diverse site demands without relying on rentals or subcontractors.
A well-balanced fleet might include:

• A compact excavator (1.5–3.5 tons) for tight access and utility work
  
• A mid-size unit (8–14 tons) for general excavation and drainage
  
• A full-size machine (20+ tons) for bulk earthmoving and demolition
  

Terminology:

• Compact Excavator: A small, tracked machine designed for precision digging in confined spaces.
  
• Full-Size Excavator: A large machine with extended reach and breakout force, used for heavy-duty excavation.
  

In New Zealand, a contractor operating near Auckland shared that his fleet of three excavators allowed him to tackle everything from driveway prep to hillside drainage without waiting on equipment availability.
Brand Diversity and Maintenance Strategy
Running machines from different manufacturers—such as Hitachi, Komatsu, and Kobelco—can be both a strength and a challenge. Each brand brings unique hydraulic characteristics, cab ergonomics, and parts availability. However, managing service intervals and stocking filters across brands requires discipline.
Advantages of brand diversity:

• Access to specialized features (e.g., Hitachi’s smooth hydraulics, Komatsu’s fuel efficiency)
  
• Better resale options across markets
  
• Reduced downtime if one machine is out for service
  

Challenges:

• Different filter types and fluid specs
  
• Varying diagnostic systems and service tools
  
• Operator training across control layouts
  

Terminology:

• Hydraulic Characteristic: The responsiveness and flow behavior of a machine’s hydraulic system.
  
• Service Interval: The recommended operating hours between maintenance tasks like oil changes or inspections.
  

A fleet manager in Victoria noted that while his Komatsu PC138 was easier to service, his Kobelco SK135 offered better fuel economy on long trenching jobs. Keeping both allowed him to match machine to task.
Transport and Logistics Considerations
Owning multiple excavators means planning for transport between job sites. Compact machines can be trailered behind medium-duty trucks, while larger units require lowboys and permits. Operators often stagger jobs to minimize transport costs and maximize uptime.
Transport tips:

• Use tandem axle trailers for machines under 8 tons
  
• Schedule jobs geographically to reduce haul distances
  
• Maintain tie-down chains and track locks for safety
  
• Verify weight ratings before loading
  

Terminology:

• Lowboy Trailer: A heavy-duty trailer with a low deck height, used for hauling large equipment.
  
• Track Lock: A device that secures the excavator’s tracks during transport.
  

In 2021, a contractor in Queensland saved over $4,000 in transport fees by grouping three jobs within a 10-kilometer radius and rotating his 12-ton machine between them.
Matching Attachments to Machine Size and Job Type
A diverse fleet allows operators to equip each machine with attachments suited to its size and function. Compact units may run tilt buckets and augers, while larger machines handle hydraulic breakers and thumbs. Quick couplers make switching tools efficient and reduce idle time.
Attachment strategy:

• Tilt bucket on compact unit for grading and shaping
  
• Auger on mid-size machine for post holes and drainage
  
• Hydraulic thumb on full-size excavator for demolition and sorting
  
• Ripper tooth for breaking hardpan or tree roots
  

Terminology:

• Quick Coupler: A mechanism that allows fast attachment changes without manual pin removal.
  
• Hydraulic Thumb: A movable clamp that works with the bucket to grab and lift materials.
  

A contractor in Rotorua shared that his 3-ton digger with a tilt bucket was ideal for shaping garden beds, while his 20-ton unit with a thumb handled concrete removal on commercial sites.
Preventive Maintenance Across a Mixed Fleet
Maintaining multiple excavators requires a structured approach to service tracking. Using a digital log or fleet management software helps monitor oil changes, filter replacements, and wear part inspections. Operators should standardize fluids where possible and train staff to recognize early signs of failure.
Maintenance checklist:

• Track hours weekly and log service events
  
• Inspect undercarriage components monthly
  
• Replace hydraulic filters every 500 hours
  
• Grease pivot points daily during active use
  
• Sample engine oil annually for wear metals
  

Terminology:

• Wear Metals: Microscopic particles in oil that indicate internal component wear.
  
• Pivot Points: Joints where movement occurs, requiring regular lubrication.
  

In 2023, a small contractor in Dunedin reduced downtime by 30% after switching to a cloud-based maintenance tracker that alerted him to upcoming service needs across his fleet.
Conclusion
Owning a mixed fleet of excavators offers unmatched versatility for contractors handling varied job scopes. By selecting machines across sizes and brands, matching attachments to tasks, and maintaining a disciplined service schedule, operators can maximize productivity and minimize downtime. Whether shaping a driveway or clearing a hillside, the right digger—used at the right time—makes all the difference. In earthmoving, diversity isn’t just strategic—it’s essential.