Bored piling is the most common foundation drilling technique in the world, dating back to the beginning of the last century.
The bored piles operational sequence is cyclical. The drilling phase includes lowering the kelly bar until it reaches the bottom of the pile, drilling up to fill the tool, raising the kelly bar out of the borehole, and discharging the cutting from the tool.
Because of its cyclical nature, each of these operations needs to be as fast and accurate as possible to achieve the best drilling performance. This means that the most common drill tool, the auger, must be perfectly clean after the discharge phase.
Soilmec over the years has invented, developed, and improved a special spoil discharge system: the Spin-Off system. This system uses centrifugal force to cleanly detach the soil from the auger. Thanks to the use of a special motor reducer mounted on the lower part of the rotary head, the kelly bar is counterclockwise rotated and the debris are completely removed by centrifugal force generated by rapid auger rotation.
Other methods, based on turning the kelly bar left and right until the soil is removed, are less effective — especially in the presence of cohesive soils such as clays and silts.
Under these conditions, the Soilmec Spin-Off system ensures the best tool cleanliness and saves at least 5 seconds during every cycle.