An enormous stone protruded from the ground there. Experts estimate that it is a billion years old. The excavation of the stone, which had been awaited with excitement, and its removal on a Cometto SPMT self-propelled vehicle have now taken place. The "menhir carrier" Obelix from the famous Asterix comics couldn't have done it better.
It had been known for decades that a gigantic stone was sleeping in the ground here. The farmer's plough has been damaged several times after contact with the tip of the colossus. However, the experts only learned its true dimensions after its full exposure in 2020. The 5.8 metre-long, 4.9 metre-wide and 2.9 metre-high "Boulder of Hüven" has developed into a visitor magnet since then.
Historic freight on an 18-axle Cometto SPMT combination
The stone, which was initially estimated to weigh 100 to 140 tonnes, was now to be freed from its hole in the ground. The Gertzen company was responsible for this project. During the preparations, a 370 metre-long construction road made of steel plates was laid across the field, over which both the crane and the self-propelled SPMT transport combination rolled to the find spot.
With the necessary precision, the crane lifted the stone and placed it carefully on the heavy load module. "The choice fell on an 18-axle combination, as the 4.5 kilometre-long route may only be driven along with a maximum axle line load of 12 tonnes. The only option for this task was such a self-propelled vehicle due to its manoeuvrability and its cross-country mobility," says company manager Wolfgang Gertzen, explaining the technical reasons for using the self-propelled vehicle.
And precisely these advantages were called for in 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 350 millimetres to allow the narrow point to be safely passed.
Electronic steering and a 700 mm stroke as decisive trump cards
The real challenge faced Gertzen at the next 90-degree bend and the exit onto the country road. The electronic steering of the Cometto self-propelled modular transporter showed its strengths here. With the help of the front steering mode and diagonal driving, the 29.30 metre-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 degrees by radio control. In order to gain additional height, the axles of the SPMT were extended upwards by 350 mm. 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-degree manoeuvre was necessary. As the crossroads here is smaller than the vehicle is long, the manoeuvre was only possible through the selection of an additional steering program – in this case the carousel drive. "Such challenging and unusual steering manoeuvres and driving around bends can only be accomplished with electronic steering," says Joachim Kolb, Sales Manager at Cometto, describing the strengths of the self-propelled transport vehicle for such assignments.
New role of the boulder in the town centre
The boulder is taking a leading role in the redesign of the central main square in Hüven. It is the last stage of a long journey, because the stone made its way from Norway to the find spot in a glacier during the last-but-one ice age. During this era, around 150,000 to 200,000 years ago, the ice sheet also created the rise on which the stone ultimately lay through the rubble and sand masses carried along with the glacier.
After a journey time of one hour, the Gertzen team reached its destination with the historic freight. The SPMT axle lines from Cometto were used in this mission in "cross-hire rental", because apart from the 6 axle lines and the power pack unit from Gertzen's vehicle fleet, two 6-axle SPMT units from the Schares company of Bocholt were also attached. Proof that bundled forces and compatible materials can be turned into a strong unit.