11 hours ago
The Scenario: Repositioning a Topsoil Stockpile
During a pond excavation project, a crew stripped and stockpiled topsoil and sand to the side of the site. Later, due to a change in pond dimensions, the pile had to be moved an additional 60–80 feet. The question arose: which machine would have moved the material faster—a Case 1150 dozer or a Kobelco SK200 Mark 8 excavator?
The pile was approximately 15 feet high and 20–30 feet long, composed of loose topsoil. The operator spent a full day pushing the material with the dozer, prompting reflection on whether another method might have been more efficient.
Understanding the Machines Involved
- Dozer (Case 1150): A medium-sized crawler dozer with a straight or semi-U blade, designed for pushing material over short distances.
- Excavator (Kobelco SK200 Mark 8): A 20-ton class hydraulic excavator with a reach of approximately 32 feet and a bucket capacity of around 1.0–1.2 cubic yards.
- Scraper (Towed Pan or Motor Scraper): A specialized earthmoving machine designed to cut, load, haul, and dump material over medium to long distances.
Terminology Note: Slot Dozing and Double Handling
- Slot Dozing: A technique where the dozer creates a confined path (slot) to contain material, increasing blade load and efficiency.
- Double Handling: Moving the same material more than once due to poor planning or design changes, leading to wasted time and fuel.
Dozer Efficiency: The Power of Slot Pushing
Experienced operators agree that a dozer, when used correctly, can outperform an excavator in short-distance material relocation. The key is to climb onto the pile and use gravity to assist in slot dozing. This method allows the blade to carry a full load with minimal spillage, especially when the material is loose and dry.
However, inefficiency arises when operators attempt to side-cut or push from the base without establishing a slot. This leads to reduced blade capacity and longer cycle times.
Excavator Limitations: Reach and Rehandling
While excavators excel at digging and loading, their efficiency drops when tasked with moving material horizontally over distances beyond their reach. In this case, the 32-foot reach of the Kobelco would require multiple cycles to reposition the pile 60–80 feet. Each cycle involves:
Scraper Considerations: Haul Distance and Site Conditions
Scrapers shine when haul distances exceed 300 feet. For shorter moves, like 60–80 feet, deploying a scraper may not be cost-effective unless one is already on site. Towed pans require dozer support to load efficiently, while motor scrapers need ample room and firm ground to operate.
In one case, a contractor used four 27-yard scrapers to correct a GPS model error that misaligned retention ponds by 100 feet. The scrapers moved thousands of cubic yards in days—but only because the haul distance justified their use.
Planning Pitfalls: The Cost of Design Changes
A recurring theme in earthmoving is the cost of poor planning. In this scenario, the customer changed the pond size after the topsoil was placed, requiring the pile to be moved again. This kind of double handling is common and costly.
A famous example occurred at a mining site where a 10-million-ton waste stockpile was built over gold-bearing ore. The entire pile had to be relocated, contributing to the company’s financial collapse.
Volume Estimation and Time Analysis
Assuming the pile measured 15 ft × 15 ft × 30 ft, the volume would be approximately 250 cubic yards. A dozer pushing this over 80 feet should not take a full day under ideal conditions. Factors that may have contributed to delays include:
- Dozer blade capacity: 3–5 cubic yards per pass
- Excavator bucket capacity: 1.0–1.2 cubic yards
- Scraper load capacity: 20–27 cubic yards
- Optimal dozer push distance: 1–300 feet
- Scraper efficiency range: 300–1,000 feet
- Excavator/truck combo: Best for >1,000 feet or confined loading zones
Recommendations for Future Projects
- Conduct pre-excavation planning with GPS modeling and contingency zones
- Use slot dozing techniques for short-distance pushes
- Avoid side-cutting with dozers unless necessary for shaping
- Present clients with cost breakdowns for change orders
- Document material volumes and movement paths for accountability
- Train operators in efficient blade and bucket techniques
Anecdote: The Pan vs. Truck Debate
One contractor debated whether to use a towed pan or an articulated truck with an excavator. While the truck/excavator combo was faster, the pan was significantly cheaper. In regions without access to articulated trucks, renting adds cost and complexity. Ultimately, the pan was chosen for its simplicity and lower operating expense.
Conclusion: Matching Method to Distance and Material
The fastest method to move earth depends on distance, material type, equipment availability, and operator skill. For short pushes under 300 feet, a properly operated dozer is hard to beat. Excavators are better suited for digging and loading, while scrapers dominate long hauls. The real key lies in planning—because moving dirt twice is rarely profitable, and often entirely avoidable.
During a pond excavation project, a crew stripped and stockpiled topsoil and sand to the side of the site. Later, due to a change in pond dimensions, the pile had to be moved an additional 60–80 feet. The question arose: which machine would have moved the material faster—a Case 1150 dozer or a Kobelco SK200 Mark 8 excavator?
The pile was approximately 15 feet high and 20–30 feet long, composed of loose topsoil. The operator spent a full day pushing the material with the dozer, prompting reflection on whether another method might have been more efficient.
Understanding the Machines Involved
- Dozer (Case 1150): A medium-sized crawler dozer with a straight or semi-U blade, designed for pushing material over short distances.
- Excavator (Kobelco SK200 Mark 8): A 20-ton class hydraulic excavator with a reach of approximately 32 feet and a bucket capacity of around 1.0–1.2 cubic yards.
- Scraper (Towed Pan or Motor Scraper): A specialized earthmoving machine designed to cut, load, haul, and dump material over medium to long distances.
Terminology Note: Slot Dozing and Double Handling
- Slot Dozing: A technique where the dozer creates a confined path (slot) to contain material, increasing blade load and efficiency.
- Double Handling: Moving the same material more than once due to poor planning or design changes, leading to wasted time and fuel.
Dozer Efficiency: The Power of Slot Pushing
Experienced operators agree that a dozer, when used correctly, can outperform an excavator in short-distance material relocation. The key is to climb onto the pile and use gravity to assist in slot dozing. This method allows the blade to carry a full load with minimal spillage, especially when the material is loose and dry.
However, inefficiency arises when operators attempt to side-cut or push from the base without establishing a slot. This leads to reduced blade capacity and longer cycle times.
Excavator Limitations: Reach and Rehandling
While excavators excel at digging and loading, their efficiency drops when tasked with moving material horizontally over distances beyond their reach. In this case, the 32-foot reach of the Kobelco would require multiple cycles to reposition the pile 60–80 feet. Each cycle involves:
- Digging
- Swinging
- Dumping
- Repositioning
Scraper Considerations: Haul Distance and Site Conditions
Scrapers shine when haul distances exceed 300 feet. For shorter moves, like 60–80 feet, deploying a scraper may not be cost-effective unless one is already on site. Towed pans require dozer support to load efficiently, while motor scrapers need ample room and firm ground to operate.
In one case, a contractor used four 27-yard scrapers to correct a GPS model error that misaligned retention ponds by 100 feet. The scrapers moved thousands of cubic yards in days—but only because the haul distance justified their use.
Planning Pitfalls: The Cost of Design Changes
A recurring theme in earthmoving is the cost of poor planning. In this scenario, the customer changed the pond size after the topsoil was placed, requiring the pile to be moved again. This kind of double handling is common and costly.
A famous example occurred at a mining site where a 10-million-ton waste stockpile was built over gold-bearing ore. The entire pile had to be relocated, contributing to the company’s financial collapse.
Volume Estimation and Time Analysis
Assuming the pile measured 15 ft × 15 ft × 30 ft, the volume would be approximately 250 cubic yards. A dozer pushing this over 80 feet should not take a full day under ideal conditions. Factors that may have contributed to delays include:
- Inexperienced operator
- Poor slot setup
- Material cohesion (e.g., clay vs. sand)
- Equipment wear or underperformance
- Dozer blade capacity: 3–5 cubic yards per pass
- Excavator bucket capacity: 1.0–1.2 cubic yards
- Scraper load capacity: 20–27 cubic yards
- Optimal dozer push distance: 1–300 feet
- Scraper efficiency range: 300–1,000 feet
- Excavator/truck combo: Best for >1,000 feet or confined loading zones
Recommendations for Future Projects
- Conduct pre-excavation planning with GPS modeling and contingency zones
- Use slot dozing techniques for short-distance pushes
- Avoid side-cutting with dozers unless necessary for shaping
- Present clients with cost breakdowns for change orders
- Document material volumes and movement paths for accountability
- Train operators in efficient blade and bucket techniques
Anecdote: The Pan vs. Truck Debate
One contractor debated whether to use a towed pan or an articulated truck with an excavator. While the truck/excavator combo was faster, the pan was significantly cheaper. In regions without access to articulated trucks, renting adds cost and complexity. Ultimately, the pan was chosen for its simplicity and lower operating expense.
Conclusion: Matching Method to Distance and Material
The fastest method to move earth depends on distance, material type, equipment availability, and operator skill. For short pushes under 300 feet, a properly operated dozer is hard to beat. Excavators are better suited for digging and loading, while scrapers dominate long hauls. The real key lies in planning—because moving dirt twice is rarely profitable, and often entirely avoidable.
