As the Shipek grab comes into contact with the sea floor, the trigger weight releases the helical springs causing the sediment bucket to rotate by 180° and scoop up the sediment sample. Once the bucket has rotated, it remains closed by the residual torque of the same helical springs, thereby protecting the sediment sample.
The rotation of the bucket is quick and penetrates the sediment cleanly, particularly if sampling clays, muds, silts or sands. Once closed, the sample is completely enclosed, therefore preventing washout during retrieval to the surface. Samples can be retrieved even if obstructions prevent the bucket from closing properly. Once recovered to deck, the bucket is simply removed by operating two retaining knobs. The sample is then processed as required.