Cranston Eagle Hook Testing and Recertification
When a hook is sent in to Delta T Systems for the required five year testing and recertification, it goes through a five-step process before it is returned to the ship for reinstallation and another five years of use. These steps include:
1 Tear Down and Cleaning
Each hook is completely torn down and all parts of the hook are thoroughly cleaned. Cleaning processes include but are not limited to degreasing, sand blasting, tumbling and polishing. Cleaning is an important step in the process because it removes dirt, rust and grease from any potential cracks in the hook so that those cracks will show up during the dye penetration test. After the cleaning process is complete, all parts are thoroughly inspected for cracks, deficiencies or deformations and any part that is not in excellent condition will be replaced with a new OEM part.
2 Hook Rebuilding
After the cleaning process is completed on the hook’s frame and other parts, it is rebuilt to factory specifications. During the rebuild process many of the parts are replaced with new OEM parts. Replacement parts include but are not limited to springs (lock pin spring, latch spring(s), positive lock springs), pull cable, positive lock bushings, rollers, locking nuts and labels. As part of the rebuild process, all components are checked for proper functionality and set to factory specifications.
3 Load Testing
The third step in the process is the load testing of the newly rebuilt hook. Each hook is mounted to a purpose-built load testing device and is then subjected to a load that is 2.2 times the rated Safe Working Load (SWL) of the hook for a period of five minutes. This load testing is witnessed by a licensed Professional Engineer (PE) and his certified and stamped findings will accompany the final report and certification documentation for that hook.
4 Dye Penetration Testing
The fourth step is the dye penetration test which is performed in order to find any cracks that may have been produced either in any of the welds on the hook or in any of the critical components of the hook. Once the hook has successfully completed the dye penetration test and no cracks have been found, the hook is cleaned, lubricated and packaged for shipment back to the owner.
5 Recertification Documentation
The final step in the testing and recertification process is to produce the official factory authorized documentation for the hook. The final report which includes the Profession Engineer’s stamped documentation is signed and sealed and is included in the shipment package for the hook which is to be returned to the customer. This documentation should be filed in a safe location on board the ship that the hook is to be used on so that it may be produced in the event of an inspection of the ship’s lifting appliances.
This recertification documentation is only valid for the Cranston Eagle hook, which has been tested and does not cover any of the other components of the launch and recovery system such as the cables or the davits on which the hook is mounted.
Standard turn around time for this testing procedure is two weeks from the time that the hook is received on the Delta T Systems’ loading dock, however shorter turn around times are possible if arrangements have been made in advance of Delta T Systems receiving the hook.
The required five year load testing and recertification of lifting appliances is critical to maintaining a safe working environment by ensuring that each lifting appliance is not damaged and is in good working order.