Approximately 280,000m³ of soil was moved, of which around 70,000m³ of the bulk was loamy shell limestone
A BOMAG rock crushing drum has been used for a specialist application by a contractor in Germany, where up to 70,000 m³ of limestone was crushed by the 26 tonne drum.
The BW 226 single drum roller with rock crushing drum, and the Variocontrol machine control system, which automatically controls the exciter and amplitude, was used by contractors Bantle, working on a 6.4 km long bypass project in Rottweil, in southern Germany.
Altogether, approximately 280,000 m³ of soil was moved, of which around 70,000 m³ of the bulk was loamy shell limestone with a compressive strength of over 120 MPa.
The roller was used to break and loosen the shell limestone preparing it perfectly for the crawler-mounted loader to pick up the broken stones with ease – a clear advantage for the contractor in terms of time and costs, since no crusher was needed.
The design and special geometry of the rock drum with closed edges means there are no gaps lengthwise under the drum. In contrast to other drums, the material being crushed is not “passed on”, but is picked up and broken on the first pass.
Using the Variocontrol, the drum hits the stone vertically thereby applying maximum splitting power. Unlike other systems with circular exciters, where the drum only brushes over the material being broken due to the circular motion, the unique BOMAG technology crushes with maximum vertical force.
Another advantage of the Variocontrol is that it prevents the “bow-wave problem”, when depending on soil type and travel direction the material is pushed in front of the drum.
Due to the automatic adjustment of the vibration direction to the travel direction, the material is always drawn under the drum. This also results in improved machine traction and when stationary automatically leads to minimum level amplitude so that the roller is prevented from becoming stuck.