Lifting in the city centre

13 August 2019

A Liebherr MK 88 Plus mobile construction crane was used to install an 800kg air conditioner in the old city centre of Mainz, Germany.

Apart from having to work in a restricted space, another challenge heavy-duty logistics company Riga-Mainz had to address was the change of crane requirements on site at short notice.

Due to technical problems, the air conditioner had to be positioned on a different place on the roof of a commercial building, at a greater distance from the crane.  However, this was not possible from the planned place of installation because the maximum working radius had already been required for the lifting movement.

The crane driver Alexandras Voroneckas had to change arrangements after his arrival on site.  This was tricky because the surrounding buildings and a large tree limited the alternatives for a place suitable for unfolding the jib system in the narrow street. Moreover, a passage for pedestrians had to be kept free alongside the crane in the approximately 10m-wide alley.

At the original place of installation, Voroneckas brought the folded crane into vertical position. In this configuration, the MK 88 could travel approximately 5m closer to the building and unfold its jib system there without any problem.

In order to make the last section of the required working radius available, the planned 15° luffed jib position was not used for the decisive lifting movement. However, for this purpose, the lifting tackle had to be shortened slightly because the level of the building roof was only just under the 30m hook height of the jib in horizontal position. Thus, the air conditioner could be placed very precisely thanks to the Micromove fine positioning mode.