A simple subsea lowering analysis is conducted for vessels as recommended by DNV-RP-H103, or a detailed fully coupled dynamic analysis is conducted including all important bits of lowering or recovery operations such as lift in the air, lift through splash zone, lift in the water, lowering on to the seabed and lifting off from the seabed. These tests help estimate the dynamic loads on slings and associated equipment during the lowering or recovery operations while also establishing and quantifying the restrictions for installing or recovering subsea structures. Launching substantially large or heavy jackets from the launch barge helps them float without challenges. Jacket launch analysis aims to provide the
following checks:
- Barge ballasting requirement for arriving at launch floating condition
- Jacket push/pull force required to commence launching
- Rocker arm reaction loads estimation
- Jacket launch trajectory and dive depth
- Reserve buoyancy analysis
- Sensitivity studies for jacket COG positions and friction coefficients
On the other hand, jacket docking analysis evaluates the impact interaction load between the jacket and pre-installed piles or conductor. Docking analysis declares the restrictive sea state for carrying out docking operations without exceeding the allowable docking load.
