Kobelco RK500

The RK500 made its debut as part of Kobelco’s New RK Series, aiming to meet the demands of lifting operations in rugged terrains with a blend of strength and precision. It has a maximum rated lifting capacity of 51 metric tons at a 2.9-meter radius and comes equipped with a five-section box-type telescopic boom that extends from 10.2 meters to 39.0 meters. Complementing the main boom is a two-step truss-type jib that extends to 9.0 or 15.0 meters, with offset angles of 5°, 17°, and 30°, stored alongside the boom for convenience.

Its hydraulic system incorporates two variable plunger pumps and three gear pumps, driving systems like the boom hoist, telescoping mechanisms, winches, outriggers, swing, steering, and clutch functions. The main and auxiliary winches feature hydraulic motor drives with inching capability and offer hoisting speeds of up to 122 m/min and 105 m/min respectively. Both winches are equipped with 18 mm diameter wire ropes—220 m on the main and 120 m on the auxiliary.

The carrier is powered by a Mitsubishi 6D24-TCE2/TCUA turbocharged, intercooled diesel engine with a displacement of 11,945 cc, generating up to 257 kW at 2,200 rpm. The engine pairs with a 3-speed transmission with a high/low shift, enabling a maximum travel speed of 49 km/h and gradeability of up to 31°. The vehicle features a fully automatic hydro-pneumatic suspension and four fully floating drive-steer type axles.

One of the RK500’s standout traits is its robust outrigger system. Hydraulic H-type outriggers extend to a maximum of 7.4 meters, with intermediate extension positions at 6.8 m, 5.4 m, 4.1 m, and a minimum of 2.55 m. Rated capacities vary depending on outrigger extension and boom configuration, but the crane is engineered to maintain operational stability even with partial extension.

Safety is a critical focus, equipped with a comprehensive array of systems including a moment limiter, working range limiters, swing stop devices, and overhoist prevention features. The operator’s cab provides a full-view, all-weather environment with adjustable seating, sliding windows, and integrated wiper systems for comfort and visibility.

In pick-and-carry mode, the RK500 is capable of lifting while moving at speeds up to 2.0 km/h, supported by advanced steering options including normal, rear, crab, and coordinated 4-wheel steer modes. Its hydraulic systems, auxiliary features like air conditioning, and the optional extra oil cooler for demanding jobs make this model particularly suitable for continuous operation in tough environments.