Demag AC 665J

The Mannesmann Demag AC 665J all-terrain crane is engineered to handle heavy-duty lifting projects with precision and efficiency. With a maximum lifting capacity of 250 tons, the AC 665J offers impressive performance in industrial plant work, infrastructure assembly, and large-scale construction operations.

At the core of the AC 665J is its robust main boom system, which extends from 14.7 meters up to 58 meters. The boom features a five-section, fully hydraulic telescoping design with an octagonal cross-section for optimal strength-to-weight performance. This system provides quick extension and retraction with high telescoping capacities, enabling the crane to adapt swiftly to varying site conditions.

For extended reach and complex lifts, the crane offers additional options with a fixed jib ranging from 7.0 meters to 41.0 meters (with offsets at 3° and 20°), and a luffing jib that can reach up to 65.0 meters. These configurations yield a maximum tip height of 84 meters, expanding the crane’s versatility for high-rise lifts and long working radii.

Powered by the Daimler-Benz OM442LA engine — an 8-cylinder, water-cooled, turbocharged diesel delivering 550 hp (405 kW) at 2100 rpm and peak torque of 239 kgm at 1100 rpm — the AC 665J delivers smooth, consistent power on- and off-road. It achieves a maximum travel speed of 70 km/h, thanks to its advanced 4-axle drive system with hydropneumatic suspension and a 16-speed transmission.

The crane carrier measures 14.625 meters in length and 3.0 meters in width, with a total vehicle weight of 33,800 kg. The drive and steering axles are configured for multi-mode steering (2, 3, 5, and 6), allowing excellent maneuverability in confined spaces.

Operational features include two powerful hoists, each capable of 132 meters per minute rope speed using 23 mm diameter wire rope (with maximum lengths of 350 m and 470 m). The swing system offers 360-degree continuous rotation with a maximum swing speed of 1.5 rpm. The boom elevation range is from -1.3° to +82.5°, with boom head sheaves arranged in a rotary style.

Safety and operational aids include load moment indicators, anti-two-block systems, outrigger position sensors, third wrap indicators, boom angle and length sensors, and integrated hydraulic safety valves across all load-bearing cylinders. The crane also incorporates drum rotation indicators and built-in hydraulic brakes to prevent uncontrolled movement in case of failure.

The AC 665J offers various hook block configurations, including:

• 250-ton hook block with 9+7 sheaves (28 falls), weighing 4,500 kg
• 184-ton block with 9 sheaves (18 falls), weighing 2,000 kg
• 111-ton block with 5 sheaves (11 falls), weighing 1,250 kg
• 31-ton single hook (3 falls), weighing 750 kg
• 10-ton single hook, weighing 500 kg

Optional equipment includes a super lift attachment for additional lift capacity and a heavy-duty luffing jib extension system.

With its advanced control systems, operator-focused cab design, and high-strength structural components, the Demag AC 665J is built to deliver reliable performance on the most challenging lifting projects, providing an excellent balance of lifting power, reach, and mobility.