Liebherr’s new MK 73-3.1 mobile construction crane

The new MK 73-3.1 is the smallest model in Liebherr’s mobile construction crane family. This compact three-axle crane is suitable for use in restricted job sites, featuring a 6-tonne maximum load capacity, a total length of 13.80 m, a width of 2.75 m and a height of 4.0 m.

The electrically-operated MK 73-3.1 can be supplied with site power or powered by its integrated generator. The crane is designed for operation with 63 or 32 amps, and there are no restrictions in working speed when using the 32 amp option, said Liebherr.

The new MK 73-3.1 is also designed as a taxi crane. As such, it is intended for one-man operation and can be set up in around 10 minutes, without additional transport vehicles, according to Liebherr. This new crane complements the other models in the series, the MK 88-4.1 and MK 140.

With a jib length of 38.5 m, the new MK 73-3.1 offers a jib head load capacity of 2,000 kg with corresponding additional ballast. In a 45-degree luffed jib position, the crane reaches a lifting height of 51 m and has a maximum lifting capacity of 2,800 kg; up to 1,850 kg at the jib head. Three possible luffed jib positions are available, allowing for flexible operation.

The crane operator is supported by a number of assistance systems. Highlights include an infinitely adjustable lift cabin and modern camera systems – both load and undercarriage are always in view. The Micromove fine positioning mode ensures precise load handling. Five steering programmes with active rear axle steering and half-sided support enable the crane to be used on particularly tight construction sites.

Other features such as the Load Plus load curve and reinforced trolley travel gear further increase the crane’s performance. This enables up to 50% heavier loads to be lifted in a 45° luffed position, said Liebherr.

The MK 73-3.1 has also adoped the single-engine concept. The electric generator on the crane is only operated by the travel motor in the undercarriage. In addition, the ECO mode ensures reliable travel and economical operation on site.