Gigantic stone move

6 January 2021

A Cometto SPMT self-propelled vehicle was used to move a 5.8m-long, 4.9m-wide and 2.9m-high stone from a field in Hüven to the small town’s centre.

The stone has gained the attention of historians, as it is believed to be hundreds of thousands of years old.

The Gertzen company was responsible for the project, which involved the lifting of the stone and the transportation to the town centre. Gertzen deployed a Liebherr all terrain crane and a Cometto SPMT self-propelled vehicle. Apart from the six axle lines and the power pack unit from Gertzen's vehicle fleet, two six-axle SPMT units from Schares’s fleet were also attached.

"The choice fell on an 18-axle combination, as the 4.5km-long route may only be driven along with a maximum axle line load of 12t. The only option for this task was such a self-propelled vehicle due to its manoeuvrability and its cross-country mobility," said company manager Wolfgang Gertzen.

In order for these machines to reach their position on the job site, a 370m-long road made of steel plates was prepared across the field. The crane then lifted the stone and placed it on the heavy-load module, which was then ready for its journey.

The manoeuvrability of the vehicle was required as early as the first bend, where an overhead power line had to be driven under. The SPMT operator Ingo Wiggelinghoff lowered the combination in travel mode by 350mm to allow the narrow point to be safely passed.

The real challenge faced Gertzen at the next 90° bend and the exit onto the country road. With the help of the front steering mode and diagonal driving, the 29.3m-long combination eased itself into the lane with pinpoint precision.

In this bend there was also a power distribution box in the way of the power pack unit. Operator Ingo swivelled the engine unit hydraulically upwards by 12° using radio control. In order to gain additional height, the axles of the SPMT were extended upwards by 350mm. The lower edge of the engine unit thus floated just a few millimetres above the power box and an interruption in the transport was avoided.

Having arrived in the centre of the town, a further 90° manoeuvre was necessary. As the crossroads were smaller and the vehicle is long, the manoeuvre was only possible through the selection of an additional steering program – in this case the carousel drive.

After a journey time of one hour, the Gertzen team reached its destination with the historic freight. The boulder is taking a leading role in the redesign of the central main square in Hüven.