Komatsu HD785-7 Overview & Specifications
The Komatsu HD785-7 is a high-performance rigid dump truck built for heavy-duty hauling operations in mining sites, quarry projects, and large-scale earthmoving environments. Known for its durability and stable performance, this truck is designed to deliver high productivity while maintaining operator safety and long-term reliability.
With its strong power output, high payload capability, and robust braking system, the HD785-7 is an excellent solution for hauling large volumes of material such as overburden, coal, rock, and soil in demanding terrain and long working cycles.
One of the biggest advantages of the HD785-7 is its balance between high payload capacity and operational efficiency, making it suitable for continuous production targets where uptime and safety are critical.
Main Function of Komatsu HD785-7
The primary function of the Komatsu HD785-7 is to:
- Transport heavy materials efficiently from loading points to dumping areas.
- Support continuous hauling cycles in mining production.
- Operate reliably in harsh conditions such as steep haul roads, uneven terrain, and extreme temperatures.
Key Benefits of Komatsu HD785-7
The HD785-7 offers several operational advantages that make it a preferred rigid dump truck in mining operations:
- High Productivity
- Large payload capacity allows fewer trips and faster production output.
- Suitable for high-volume hauling operations.
- Strong Engine Performance
- Built with a powerful Komatsu diesel engine designed for heavy load and long working hours.
- Provides consistent traction and pulling power even on uphill haul roads.
- Reliable Braking System
- Equipped with oil-cooled multiple-disc braking system for both front and rear wheels.
- Designed to improve braking performance during continuous downhill hauling.
- Safety & Operator Comfort
- Ergonomic cabin design supports long working shifts.
- Enhanced stability and control systems to support safe driving.
- Durable Structure
- Designed with reinforced frame and heavy-duty components.
- Built to withstand rough mine roads and repeated heavy loads.
Komatsu HD785-7 Specifications
Below are the key technical specifications of the Komatsu HD785-7:
Engine
- Model: Komatsu SAA12V140E-3
- Type: Water-cooled, direct injection, turbocharged and after-cooled diesel engine
- Configuration: 12-cylinder
Net Power Output
- 879 kW (1,178 HP) @ 1900 rpm
Braking System
- Oil-cooled, multiple-disc service brakes (front and rear)
- Full hydraulic braking system designed for high safety performance
- Retarder support for better downhill control
Capacity
- Rated Payload (Net Load Capacity): approximately 91 tons
- Dump Body Capacity: approximately 40 m³
Dimensions
- Overall Transport Length: 11.02 meters
- Overall Width: 5.53 meters
- Overall Height: 5.05 meters
Maximum Travel Speed
Transmission
- Full automatic planetary transmission
- 7 forward speeds and 2 reverse speeds
Gross Vehicle Weight (GVW)
Operating Guide (Basic Professional Operation)
Below is a practical and professional overview on how to operate the Komatsu HD785-7 safely.
- Pre-Start Inspection (Before Operating)
Before starting the HD785-7, the operator should always perform a complete walk-around inspection:
- Check engine oil level
- Check coolant level
- Check hydraulic oil level
- Inspect tires for damage and correct pressure
- Inspect brake condition and brake fluid level
- Check fuel level
- Inspect for leaks under the unit
- Ensure lights, horn, reverse alarm, and safety devices are working properly
- Ensure dump body is fully lowered and secure
This inspection is important to reduce breakdown risk and ensure safe operation.
- How to Start the Komatsu HD785-7
To start the unit properly:
- Ensure the surrounding area is clear of personnel and obstacles.
- Climb into the cabin using 3-point contact.
- Sit properly and adjust the seat and mirrors.
- Fasten the seat belt.
- Confirm the transmission is in Neutral (N).
- Apply the parking brake.
- Turn the ignition key to the ON position and allow system checks to complete.
- Start the engine and let it idle for a few minutes.
- Monitor dashboard indicators (oil pressure, temperature, warning lights).
Do not rush the warm-up process, especially in cold environments or after long shutdown periods.
- How to Operate / Drive the HD785-7
When the unit is ready to move:
- Release the parking brake only when the route is clear.
- Select the appropriate gear smoothly.
- Accelerate gradually to avoid sudden stress on drivetrain components.
- Follow site speed limits and haul road rules.
- Always maintain safe distance from other equipment.
- Use retarder and service brakes correctly on downhill roads.
- Avoid sharp turns at high speed, especially when fully loaded.
Loading Operation
During loading:
- Position the truck properly under the excavator/shovel.
- Stay in the correct loading zone and remain stable.
- Avoid sudden movement while being loaded.
- Do not exceed rated payload capacity.
Dumping Operation
During dumping:
- Stop on level and stable ground.
- Apply parking brake.
- Raise the dump body slowly and steadily.
- Ensure material is fully discharged.
- Lower the dump body completely before moving again.
- How to Stop and Shut Down the HD785-7
To shut down safely:
- Park the truck on stable ground.
- Shift transmission to Neutral.
- Apply the parking brake.
- Ensure dump body is fully lowered.
- Let the engine idle for 3–5 minutes to cool down.
- Turn off the engine.
- Remove the key.
- Conduct a short post-operation check (leaks, tire condition, unusual heat, etc.).
This shutdown procedure helps extend engine life and prevents overheating damage.
Conclusion
The Komatsu HD785-7 is a highly capable rigid dump truck designed for demanding heavy-haul applications. With its 91-ton payload capacity, powerful 879 kW engine output, reliable braking system, and durable build quality, it remains a strong choice for mining and quarry operations that require consistent productivity and safety.
When operated correctly following professional inspection, loading, hauling, and shutdown procedures, the HD785-7 can deliver long-term performance with reduced downtime and improved operational efficiency.
