Excavation and four different tasks
Six metres below ground level, the Rockwheel G5 Twin cut effortlessly through a further seven metres of hard rock. The result: the Graf Group completed the excavations for relocating a cable conduit in Dortmund well ahead of schedule. What’s more, construction supervisor Frank Schöne was able to put the versatile Rockwheel to work for another four different tasks.
The plan was to break up the hard rock in the trench in the good old way with a hydraulic breaker. To cut the trench, construction supervisor Frank Schöne attached the Rockwheel G5 Twin to the five-tonne Kubuta. However, when the Graf Group's on-site team started work, they quickly realised that the Rockwheel was able to cut right through the 80 MPa rock, dispensing altogether with the need for the hydraulic breaker. This wasn't the only benefit: the removed material made perfect gravel for refilling when the work was complete.
The contract was to relocate the conduit for a 110 kV cable just outside Dortmund. Mühlheim-based excavation firm Graf Rohrleitungs- und Tiefbau GmbH started by digging an 11 m x 7 m pit, shored with soldier pile walls to prevent soil collapses and landslides.
The pit needed to be 13 m deep, and would then form the launch point for the microtunnel boring machine to make its way below the B54. Excavations were proceeding well until the site team hit hard rock – but the Rockwheel G5 Twin took this in its stride.
“Incredible what this little machine can do”, remarked construction supervisor Frank Schöne, who has a lot of experience with hydraulic cutting units. “The Rockwheel wasn't just useful for the earthworks”, he went on. “I was able to put it straight back to work in four other projects!”
The construction site supervisor at the Graf Group used the Rockwheel to cut away asphalt, demolish walls effortlessly, cut away blast furnace slag for reuse as a road foundation, and crush reinforced concrete.
The real highlight of this success story, though, is the service. Frank Schöne found himself frankly impressed by the partnership between construction machinery firm Hopf GmbH and the manufacturer of the cutting unit, Rokla GmbH. “Marcel Scholz from Hopf really got involved in our planning”, explains Schöne. “He came up with the right cutting units at the right time. And Rokla's General Manager, Robert Piasecki, brought them over personally the next day. Now that's what you call service!”
