How a 21-ton Hydraulic Excavator Was Re-engineered to Withstand Extreme Heat

It needed to handle temperates that can reach 122 degrees Fahrenheit.

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Zoomlion

Zoomlion developed a 21-ton crawler hydraulic excavator for the extreme heat, dusty conditions and prolonged breaker operations common in the Middle East.

The excavator is built for municipal construction, utility projects and mining operations, where temperatures can exceed 50 degrees Celsius (about 122 degrees Fahrenheit) and hydraulic breaker work may account for more than 70% of operating time.

"Customers in the Middle East do not simply need another excavator. They need one that can keep working," said Wu Baoshuo, deputy director of the Medium and Large Excavator Research Institute at Zoomlion Earthmoving Machinery Company. "The conditions are very different from conventional earthmoving, so the machine has to be developed around the realities of the local jobsite."

Wu led the project from design and testing through optimization and mass production. One of the team's biggest challenges was controlling heat during prolonged breaker operations. The combination of continuous breaker work and extreme temperatures placed heavy demands on the cooling system.

The team redesigned the airflow layout and optimized the cooling core to improve heat dissipation. Engineers also strengthened key structural components and refined welds to reduce stress during repeated impact. To improve dust protection, they enhanced the air intake system and cab sealing.

The team tested each improvement at customer worksites in the Middle East, using sensors to collect data and completing thousands of breaker cycles to refine the design.

The project brought together teams across product development, testing, manufacturing, technical support and overseas operations, while Zoomlion's testing center at its headquarters supported three months of high-frequency breaker durability testing.

The development process required repeated testing and refinement. When an early cooling design needed further adjustment, the team used the data to adjust the system and move forward.

"Innovation always comes with lessons," Wu said. "The company's support gave us the confidence to keep solving tough engineering challenges."

For Wu and his team, the award recognizes years of customer-focused engineering. "It is an honor, but not the finish line," he said. "We will keep learning from the jobsite and building equipment customers can rely on."

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