Design, manufacture and use of modified grapnels in anchoring operations

Abstract

The mooring departament has the Grapnel in its list of equipment, which is probably the most iconic and representative equipment for mooring and anchor handling activities. This article presents the application of two innovative tools based on modified Grapnels of 400t SWL, one developed for cutting polyester ropes and the other for lifting mooring lines in restricted areas. The modfied Grapnel cutting tool, has a robust design and the use of resistant blades on each of its 4 legs, which allow cuts to be made in tensioned polyester cables. Its simplicity of operation and mobility make it ideal for use in access restricted areas, where operations with ROVs would become unsafe or impracticable, providing greater versatility and saving resources. The second modified Grapnel arises from the need to carry out maintenance interventions in extremely congested areas, where the application of the conventional Grapnel fishing method proved unsafe or even impossible, and the alternative fishing solutions with wire ropes and hooks brings the risk of rupture of the arrangements. These are already consolidated equipment, applied in most Petrobras' Anchoring operations, and are innovations so effective that other applications have emerged, allowing, in addition to the initially designed tasks, the replacement of other equipment in a range of operations with increased efficiency and safety.