Kobelco 7250-2

The Kobelco 7250-2 crawler crane offers a maximum lifting capacity of 250 metric tons (276 US tons) and is equipped with a main boom that extends up to 76.2 meters. It supports additional configurations including a long boom reaching up to 91.4 meters and a luffing tower system with a maximum boom and jib combination of 64.1 meters plus 51.8 meters, offering high operational flexibility.

The crane’s lattice boom and jib are constructed from high-tensile tubular steel for strength and durability, with pin connections between sections for ease of assembly. The fixed jib option provides a 30.5-meter extension when combined with the main boom, while the luffing jib can reach 51.8 meters.

Powered by a Mitsubishi 6D24-TLE2A water-cooled, direct injection diesel engine rated at 235 kW at 2,000 rpm, the 7250-2 is compliant with Tier II emission standards. The crane’s hydraulic system consists of four variable displacement piston pumps, delivering smooth and efficient operation with maximum system pressure of 32.0 MPa (325 kgf/cm²). It includes full-flow hydraulic controls for hoist, swing, and propel functions, with separate circuits for improved multitasking.

Main and auxiliary winches are driven by hydraulic motors with planetary reducers. The rated single-line pull is 132 kN (13.5 tf) with a line speed of up to 110 m/min on the first layer. Wire ropes measure 28 mm in diameter, and the main winch offers 390 meters of storage capacity.

Swing capability is full 360 degrees with a maximum swing speed of 2.2 min⁻¹. Travel speed tops at 1.1 km/h with a maximum gradeability of 30%. The crane’s carbody is supported by crawler tracks with 1,070 mm wide shoes (optional 1,220 mm) and sealed track rollers for maintenance-free operation.

Operating weight varies based on configuration, with approximately 208 tons when fully equipped. Ground pressure ranges from 114 kPa (1.16 kgf/cm²) under the main boom to 120 kPa under the luffing tower configuration. The counterweight system includes 97.1 tons on the upper and 20 tons on the lower section, supporting both stability and transport ease.

The operator’s cab is designed for visibility and comfort, featuring full glass panels, adjustable seating, air conditioning, and integrated control systems. The crane supports four-lever controls and joystick options, and is equipped with standard safety and operational monitoring systems.