Liebherr MK 140

The Liebherr MK 140 represents a major step forward in the evolution of mobile construction cranes and stands at the top end of the MK range. Developed to meet the demands of high-rise and inner-city construction, the MK 140 combines classic MK fast self-erection capability with a sophisticated VarioJib concept that allows operation either as a horizontal trolley jib crane or as a luffing jib crane. This dual-mode capability is a defining feature, giving contractors the flexibility to adapt to restricted airspace, overlapping cranes, and changing site conditions without changing equipment.

In trolley mode, the MK 140 is equipped with a four-section lattice jib offering a maximum radius of 58.5 metres. In this configuration, the crane achieves a maximum lifting capacity of 8,000 kg at short radii and can handle approximately 1,700 to 1,900 kg at the maximum radius, depending on jib configuration and ballast. The jib can also be set at fixed angles of 0°, 15°, 30°, and 45°, increasing hook height and optimizing load paths for various construction stages. With the jib raised, the crane reaches hook heights in the region of 75 metres. The extremely tight and high assembly curve allows erection in confined spaces, a hallmark of the MK design philosophy.

A key innovation of the MK 140 is its VarioJib luffing mode, which allows the jib angle to be adjusted steplessly from –20° up to 70° under load. In this mode, the crane achieves outstanding hook heights of up to approximately 94 metres, making it suitable for tall residential towers, office buildings, and projects where oversailing adjacent properties must be minimized. With optional lattice jib extensions, the luffing jib length can be increased to 62.5 metres or 65 metres. Load capacities in luffing mode vary with jib angle and ballast, typically ranging from around 1,000 to 1,700 kg at large radii when fitted with the full 9.0-tonne additional ballast.

The MK 140 features a three-section telescopic tower in solid-wall construction with automatic locking to the slewing platform. Fully automatic erection is achieved at the push of a button, allowing one-man setup with minimal manual intervention. The crane does not need to be dismantled when out of service and can be placed in a wind-free slewing condition depending on configuration, improving uptime and reducing site downtime.

All crane motions are electrically driven using frequency-controlled motors. The slewing system provides stepless rotation from 0 to 0.8 rpm with electronic wind load control and automatic load sway damping. Hoisting is performed by a powerful frequency-controlled hoist with MICROMOVE precision mode, offering lifting speeds of up to 100 m/min for fast material handling combined with precise placement. Trolley travel reaches speeds of up to 80 m/min, ensuring efficient coverage of the working radius.

The crane is mounted on a Liebherr-designed six-axle carrier with a transport weight of approximately 60 tonnes, increasing to around 69 tonnes when fitted with the full 9.0-tonne additional ballast, which must be removed for road travel in accordance with national regulations. The carrier is powered by a Liebherr D946 A7 SCR six-cylinder diesel engine delivering 400 kW (544 hp), compliant with EU 97/68/EC emissions standards. Power is transmitted via a ZF 12-speed AS-TRONIC automated gearbox with intarder and a two-stage transfer case. Maximum road speed is 80 km/h, and the crane offers excellent gradeability for its class.

All axles are steered, with axles 2, 4, and 5 driven, supported by hydropneumatic suspension with automatic leveling and hydraulic locking. The four-point outrigger system is fully hydraulic with automatic leveling and electronic inclination monitoring, operable via remote control. Thanks to its favorable center of gravity, the MK 140 can be repositioned slowly on site while erected, provided the outriggers remain horizontally extended.

An elevating full-vision operator’s cab is standard, allowing stepless height adjustment to maintain optimal visibility at all times. The cab is climate controlled, ergonomically designed, and equipped with Liebherr’s Electronic Monitoring System, providing real-time data on crane configuration, support pressures, and wind conditions. Power for crane operations is supplied by an onboard 48 kVA diesel generator, with the option to connect to external 400 V site power for quieter, low-emission operation.

In summary, the Liebherr MK 140 is a flagship mobile construction crane that combines exceptional reach, high hook heights, and advanced operating modes in a single, highly mobile platform. Its ability to function both as a trolley jib and luffing jib crane makes it particularly valuable on complex urban sites where flexibility, precision, and rapid deployment are critical. All specifications and performance figures referenced are based on the manufacturer’s technical documentation.