SubscribeThe grab is a piece of equipment that has been specially developed for the aforementioned purpose.
Opening and closing is carried out by means of double-acting hydraulic cylinders arranged in a completely protected manner. The oil is fed through hydraulic tubes that can be wound up on drums that have a hydraulic rotary transmission lead through and through pipelines, which are permanently installed on the boom and fed by the shipboard crane's hydraulic equipment.
Floats have been integrated in the shells of the grabs; their buoyancy is so great that the grab floats steadily. They have been arranged in the shells in such a manner that the position of the grab in the water can be changed during the process of closing by this special arrangement of the floats. This is done in such a way that the change in buoyancy causes the closing jaws to leave their original orbit and achieve an almost horizontal position at a depth of approx. 300-400 mm below the surface of the water.
Roughly during the last third of the closing process, the buoyancy rapidly increases and the oil caught between the overlapping side jaws and the jaws underneath sloshes into the two shell halves.
Even if, during this process, objects should be caught in the jaws underneath, the oil still remains in the grab shells.
Movable, perforated sheet steel has been attached to the lower trailing edge of the shells with which the bores for the scuppers can be corrected, depending on the consistency of the oil to be recovered.
The grab is proofing his function and performance since years on board of German oil- recovering vessel “SCHARHÖRN”.
Even when the sea becomes rough and other oil- recovering equipment has to be taken back on board, the grab can still operate.
