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The Rise of Crawler Carriers in Earthmoving
Crawler carriers have become indispensable in modern earthmoving, especially in environments where wheeled vehicles struggle. These track-mounted transporters are designed to haul materials across rugged terrain, soft ground, and steep inclines. Originally developed in Japan during the 1970s, crawler carriers gained popularity in North America through brands like Morooka, IHI, and Komatsu. Their low ground pressure and high traction make them ideal for pipeline work, mine reclamation, forestry, and disaster recovery.
By 2020, global crawler carrier sales exceeded 15,000 units annually, with Morooka alone producing over 3,000 units per year. The machines range from compact models like the MST-600 to heavy-duty haulers like the Komatsu CD110R, capable of carrying over 11 tons of payload.
Slope Ratings and Gradeability Explained
Gradeability refers to the maximum slope a machine can climb under load. Most crawler carriers advertise a gradeability of 30 degrees, which translates to a 57.7% slope. This is steeper than a 2:1 slope (50%) and significantly more aggressive than a 3:1 slope (33.3%). However, real-world performance depends on soil conditions, load weight, and machine configuration.
For example:
Application on Mine Reclamation Projects
In mine reclamation, operators often face steep terrain and unstable surfaces. A 2:1 slope over a 2,000-foot elevation presents serious challenges for material transport. Traditional track loaders may struggle with traction and stability, especially when carrying riprap or gravel. Crawler carriers, with their wide tracks and balanced weight distribution, offer a safer and more efficient alternative.
Operators have reported success using Morooka MST-1500s and Komatsu CD60Rs to haul riprap uphill for ditch lining. In one case, a contractor in North Carolina used a Morooka to climb a steep mountain trail in Maggie Valley, fully loaded and in reverse, demonstrating the machine’s torque and traction.
Operational Techniques and Safety Considerations
When operating on steep slopes:
Choosing Between Rotating and Fixed Beds
Rotating upper structures allow the dump bed to swivel 180°, enabling material placement without repositioning the machine. This is useful in tight spaces or when dumping downhill. However, rotating beds increase complexity and raise the center of gravity.
Fixed-bed carriers are simpler and more stable on steep terrain. For slope work, many contractors prefer fixed beds unless precision dumping is required.
Manufacturer Insights and Limitations
While Komatsu’s CD110R is a powerful machine, its brochure cautions against use on slopes steeper than 15 degrees. This likely refers to side slopes, where tipping risk is highest. Morooka and IHI models are often preferred for steep work due to their lower profile and proven field performance.
In 2022, a new entrant—Terramac—began manufacturing crawler carriers in the U.S., offering models with enhanced safety features and customizable platforms. Their machines have been adopted in utility and environmental sectors, further expanding the crawler carrier market.
Rental and Fleet Strategies
For short-term projects, renting crawler carriers is a cost-effective solution. Rental fleets often include:
Conclusion
Crawler carriers are well-suited for steep slope work, especially in mine reclamation and remote construction. With proper machine selection, operational technique, and safety awareness, these machines outperform traditional loaders in challenging terrain. As manufacturers continue to innovate, crawler carriers will remain a vital tool for earthmoving professionals tackling the toughest jobs.
Crawler carriers have become indispensable in modern earthmoving, especially in environments where wheeled vehicles struggle. These track-mounted transporters are designed to haul materials across rugged terrain, soft ground, and steep inclines. Originally developed in Japan during the 1970s, crawler carriers gained popularity in North America through brands like Morooka, IHI, and Komatsu. Their low ground pressure and high traction make them ideal for pipeline work, mine reclamation, forestry, and disaster recovery.
By 2020, global crawler carrier sales exceeded 15,000 units annually, with Morooka alone producing over 3,000 units per year. The machines range from compact models like the MST-600 to heavy-duty haulers like the Komatsu CD110R, capable of carrying over 11 tons of payload.
Slope Ratings and Gradeability Explained
Gradeability refers to the maximum slope a machine can climb under load. Most crawler carriers advertise a gradeability of 30 degrees, which translates to a 57.7% slope. This is steeper than a 2:1 slope (50%) and significantly more aggressive than a 3:1 slope (33.3%). However, real-world performance depends on soil conditions, load weight, and machine configuration.
For example:
- Komatsu CD60R: 30° gradeability, payload ~13,000 lbs
- Morooka MST-800VD: 30° gradeability, payload ~16,000 lbs
- IHI IC-75: 30° gradeability, payload ~15,000 lbs
Application on Mine Reclamation Projects
In mine reclamation, operators often face steep terrain and unstable surfaces. A 2:1 slope over a 2,000-foot elevation presents serious challenges for material transport. Traditional track loaders may struggle with traction and stability, especially when carrying riprap or gravel. Crawler carriers, with their wide tracks and balanced weight distribution, offer a safer and more efficient alternative.
Operators have reported success using Morooka MST-1500s and Komatsu CD60Rs to haul riprap uphill for ditch lining. In one case, a contractor in North Carolina used a Morooka to climb a steep mountain trail in Maggie Valley, fully loaded and in reverse, demonstrating the machine’s torque and traction.
Operational Techniques and Safety Considerations
When operating on steep slopes:
- Ascend in reverse if the machine has better traction or visibility
- Use benches or switchbacks to reduce slope exposure
- Avoid side-hill travel with rotating upper structures
- Maintain low center of gravity by evenly distributing load
- Use slope meters to monitor incline and prevent tipping
Choosing Between Rotating and Fixed Beds
Rotating upper structures allow the dump bed to swivel 180°, enabling material placement without repositioning the machine. This is useful in tight spaces or when dumping downhill. However, rotating beds increase complexity and raise the center of gravity.
Fixed-bed carriers are simpler and more stable on steep terrain. For slope work, many contractors prefer fixed beds unless precision dumping is required.
Manufacturer Insights and Limitations
While Komatsu’s CD110R is a powerful machine, its brochure cautions against use on slopes steeper than 15 degrees. This likely refers to side slopes, where tipping risk is highest. Morooka and IHI models are often preferred for steep work due to their lower profile and proven field performance.
In 2022, a new entrant—Terramac—began manufacturing crawler carriers in the U.S., offering models with enhanced safety features and customizable platforms. Their machines have been adopted in utility and environmental sectors, further expanding the crawler carrier market.
Rental and Fleet Strategies
For short-term projects, renting crawler carriers is a cost-effective solution. Rental fleets often include:
- Morooka MST-1500 and MST-2200
- Komatsu CD60R and CD110R
- IHI IC-45 and IC-75
- Terramac RT9 and RT14
Conclusion
Crawler carriers are well-suited for steep slope work, especially in mine reclamation and remote construction. With proper machine selection, operational technique, and safety awareness, these machines outperform traditional loaders in challenging terrain. As manufacturers continue to innovate, crawler carriers will remain a vital tool for earthmoving professionals tackling the toughest jobs.
