October 4, 2010
Doosan says its new 72.1-metric-ton crawler excavator is the largest one the company manufactures. Designed for heavy-duty mining and quarrying applications, the DX700LC is powered by a six-cylinder, turbocharged Isuzu diesel engine and has an operating weight of 158,953 pounds with standard boom and arm, 35.4-inch double grouser shoes, and a 4.32-cubic-yard bucket. Bucket breakout force is 78,485 pounds with the standard bucket; arm breakout force is 64,595 pounds.
The machine’s long carriage design, combined with the 13-foot, 11-inch width of the fully expanded undercarriage, is said to offer stability and safety in all applications. The excavator works efficiently on slopes with a high swing torque of 48,369 pounds and a swing speed of 7.1 revolutions per minute.
The company says its six-cylinder, Tier III-compliant, common rail Isuzu AH-6WG1X engine features a high-pressure, fuel-injection system that improves combustion efficiency while reducing particulate matter, and exhaust gas recirculation (EGR) lowers the combustion temperature, reducing nitrogen oxide emissions. An electronic power optimizing system (e-POS), connected to the engine’s electronic control via a data transfer link, harmonizes the operation of the engine and the hydraulic system, further minimizing fuel consumption.
A new control system includes four operating modes:
The unit boasts a positive control piston pump and open center valve, which enable fine metering of hydraulic flow for smooth, precise control of machine functions. Flow regeneration conserves energy and enables increased boom and arm cycles. Boom and arm cylinders are cushioned to provide smooth end-of-stroke operation, while the holding system prevents attachments from falling when the controls are in neutral.
An automatic two-speed travel system controls travel speed and tractive force. In high range, maximum travel speed is 2.9 miles per hour.
The cab offers ergonomic controls and instrumentation. Joystick control stands raise and lower with the suspension seat while the seat itself slides forward and back to accommodate the operator. The unit is designed to keep machine noise levels as low as possible — noise level at the operator’s ear is 76 dBA, while noise level for bystanders is 108 dBA.
The machine features extended, 500-hour engine service intervals. Other maintenance features include:
The DX700LC is covered by a 48-hour parts guarantee — if a “machine-debilitating” part is needed, Doosan will deliver the part within two business days or pay for a replacement machine rental.
Operating weight 158,953 pounds
Standard bucket size 4.32 cubic yards
Optional bucket sizes 3.27 to 5.89 cubic yards
Bucket breakout force 78,485 pounds
Arm breakout force 64,595 pounds
Swing torque 48,369 pounds
Swing speed 7.1 rpm
Drawbar pull 107,806 pounds
Max. digging reach 42 feet, 7 inches
Max. digging depth 27 feet, 7 inches
Dump height 27 feet, 4 inches
Max. travel speed 2.9 mph
Track length 15 feet, 7 inches