Reviving the Excavator-Mounted Spot Mounder for Forestry Land Preparation

[MikePhua]

Origins of the Spot Mounder Concept
In the 1990s, forestry operations in Australia and New Zealand faced increasing pressure to improve land preparation efficiency while minimizing soil disturbance. This led to the development of the excavator-mounted spot mounder—a specialized attachment designed to create planting mounds for tree seedlings. Unlike traditional tillage tools, the spot mounder combined a ripping tine with a shaping blade, allowing operators to break compacted soil and form raised mounds in a single pass.
One of the early manufacturers was Wilco Products, which engineered the tool for use on mid-size excavators. The attachment replaced the bucket and operated hydraulically, enabling precise control over mound size and placement. Its success in eucalyptus and pine plantations made it a staple in mechanized forestry prep for over a decade.
Design Features and Operational Benefits
The spot mounder typically includes:

• A vertical ripper shank to penetrate compacted soil layers
  
• A curved moldboard or wing to shape the displaced soil into a mound
  
• Reinforced mounting brackets for excavator linkage
  
• Optional depth control skids or hydraulic tilt functions
  

Key advantages include:

• Reduced labor compared to manual mound building
  
• Improved root penetration due to deep ripping
  
• Consistent mound geometry for uniform seedling establishment
  
• Adaptability to varied terrain and soil types
  

In trials conducted in Rotorua, New Zealand, spot mounders increased planting productivity by 40% and reduced seedling mortality by 25% compared to flat planting on compacted soils.
Challenges in Locating Modern Units
Despite their effectiveness, spot mounders have become rare in recent years. Many original units were retired or scrapped as forestry practices shifted toward broadcast site prep or mechanized planters. Manufacturers like Wilco Products ceased production, and technical documentation became scarce.
However, remnants of the technology persist. Companies such as Devine Engineering in Taupo and Active VMA in Rotorua have experience with excavator conversions and may offer insights into legacy designs. Some operators have fabricated their own versions using stick rakes and custom moldboards, adapting the concept to local conditions.
Adapting the Tool for African Forestry
In regions like South Africa, where forestry land prep must contend with variable soils, labor constraints, and erosion risks, the spot mounder offers renewed promise. Excavator-mounted systems allow for:

• Precision placement on steep or rocky terrain
  
• Minimal soil inversion, preserving microbial layers
  
• Integration with GPS or planting maps for optimized spacing
  

To adapt the tool for African conditions:

• Use high-tensile steel for the ripper shank to handle clay and laterite
  
• Design modular wings for adjustable mound size
  
• Incorporate hydraulic float to follow uneven contours
  
• Fit quick coupler mounts for compatibility with mixed fleets
  

One forester in Pietermaritzburg reported that a modified ripper-mounder reduced site prep time by half and allowed planting crews to focus on seedling quality rather than terrain adjustment.
Recommendations for Fabrication and Deployment
For those considering building or sourcing a spot mounder:

• Study archived patents and engineering drawings from 1990s manufacturers
  
• Contact forestry equipment yards in New Zealand and Queensland for used units
  
• Partner with local fabricators to prototype and test designs
  
• Use excavators in the 12–20 ton range for optimal balance and reach
  
• Train operators in depth control and mound shaping techniques
  

Maintenance should include:

• Regular inspection of welds and shank wear
  
• Greasing of pivot points and hydraulic fittings
  
• Replacement of moldboard edges after 500–800 hours
  

Conclusion
The excavator-mounted spot mounder represents a forgotten innovation in forestry land preparation—one that deserves revival. With its ability to rip, shape, and prepare planting sites in a single motion, it offers a compelling solution for sustainable, efficient reforestation. Whether rediscovered in a New Zealand yard or reimagined in an African workshop, the spot mounder continues to prove that smart design and soil stewardship go hand in hand.