Operational planning
Jack-up operation planning, and any planning for that matter, is best done incrementally. That is, starting from a simple outline, working towards a detailed operational plan and drawings. The site-specific assessment (SSA) can grow along with the planning, from an early feasibility check to a fully optimized assessment allowing for performing safe operations in the most efficient way.
SSA optimization
For SSA optimization, it is beneficial in many cases to allow for some settlements occurring during the survival storm. In the detailed engineering phase of the SSA, these settlements are to be explicitly included in the structural model of the jack-up. This is, in ISO speak, a Step 3b acceptance check. For the advanced analysis behind this check, it is essential particularly for jack-ups with more than 3 legs, that a detailed structural model of the hull is used to correctly capture the load redistribution from the settling leg(s) to other legs. See the picture of a jack-up model with a settled leg and a tilted and deflected hull.
Acceptable tilt
Even significant settlements may yield acceptable structural checks. At Calypso, we typically accept a tilt of the hull up to 1 degree, as the foosball table should be stowed during severe storms anyways.
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