🔍 Key Concepts

• Environmental forces on offshore structures such as wind, waves, current, and tide • How overturning moment is created on a tall, elevated jack-up structure • Relative strength and variability of horizontal loads from different environmental factors in open water

💭 Think About

• Which of these forces typically produces the largest and most rapidly changing horizontal loads on offshore structures? • Think about a jack-up: once it is elevated on its legs, which force has the greatest leverage on the hull and legs to tip it? • Compare the usual magnitudes: in a storm offshore, which effect is normally designed for as the primary driver of overturning stability?

✅ Before You Answer

• Be clear that overturning mainly comes from lateral (sideways) loads acting above the seabed support points • Consider that tide mainly changes water level, not usually the dominant sideways overturning load • Remember that current is usually slower and produces steadier forces than the most critical rapidly varying loads in severe weather