The COASTAL DRILLER, while in transit, expects the winds to increase to 75 knots. In order to meet the stability and leg strength requirements, the tip-of-can (TOC) position should be at __________.
• Jack-up rig operating conditions and how wind speed affects required air gap and leg position • Relationship between tip-of-can (TOC) elevation, hull draft, and required air gap in high-wind conditions • How stability criteria and leg strength limits change between transit, preloading, and elevated modes
• Think about whether a jack-up in transit with 75-knot winds would normally have its legs fully retracted, partially lowered, or significantly extended for safety and structural reasons. • Consider what happens to bending moments and stresses in the legs when the TOC is just below, just at, or well below the hull, especially in rough seas and high winds. • Ask yourself which TOC position is most consistent with maintaining enough reserve stability without overloading the legs while the unit is still moving.
• Verify which operating mode the rig is in when the TOC position requirement is being asked (transit vs elevated). • Check how leg strength limits are affected by the amount of leg exposed below the hull when the unit is subject to high wind and wave loads. • Confirm which TOC value best balances minimal leg exposure for transit with meeting the specified 75-knot wind stability requirement.
No comments yet
Be the first to share your thoughts!