In the harsh offshore environment around the world, standard safety bow shackles are used today for lifting and towing operations that could initiate vibration and a high-cycle movement of the shackle nut against the regulation split pin.
Typical offshore usage
- Chain / Wire chasing or grappling
- Subsea buoyancy connection to chain / wire
- Lifting / lowering of subsea assets
- Spooling operations
- Back of deck lifting / manipulation
To mitigate this known hazard of a shackle nut "backing-off", and ultimately the shackle pin falling out, GN have now introduced locked-nut shackles.
These shackles will be completely standard in their dimensional requirements but will have a locking bolt inserted through the nut and pin of the shackle. The standard split pin will also be used as an extra locking mechanism
This proposed secondary locking mechanism is introduced from GN's extensive experience with LTM connectors.