Helms Geomarine can provide up to 11 meters, 4-inch piston cores that can be collected at depths in excess of 4,500m. The piston corer utilizes a cantilevered deployment platform over the side of the vessel. The piston corer consists of a 1 to 2 tons weight stand, a 4-inch core barrel, a mechanical trigger, standard schedule 40 PVC liner, a cutting shoe, and a foil core catcher.
After being lowered on a wire from the side of a ship, the piston corer approaches the seafloor preceded by the small gravity corer. Upon contact, the tripping arm “opens,” sending the piston corer on a fast fall to the bottom.
As the piston corer penetrates the seafloor, the piston inside stops at the sediment surface. The action of the piston creates a pressure differential at the top of the sediment column. This allows the soft material to enter the core liner without disruption.