The COASTAL DRILLER is experiencing a single...

Question 1 / 2707066636ee728f7522a1c517722

Question 1 of 2707066636ee728f7522a1c517722

The COASTAL DRILLER is experiencing a single amplitude roll angle of 3 degrees and a roll period of 10 seconds. What is the maximum water depth that can be used for going on location?

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Question 1 of 27070

The COASTAL DRILLER is experiencing a single amplitude roll angle of 3 degrees and a roll period of 10 seconds. What is the maximum water depth that can be used for going on location?

🔍 Key Concepts

• Roll period and how it relates to the dominant wave period in a given water depth • Deep‑water wave relation between wave period and wave length (L ≈ 5.12·T² in feet for deep water waves) • How water depth compared to wave length (deep, intermediate, shallow) affects whether it is safe to go on location for a mobile drilling unit

💭 Think About

• First, use the roll period given (10 seconds) to estimate the wave length a sea state with that period would have in deep water. How do you compute L from T? • Then, compare possible water depths in the choices to some fraction of that wave length (e.g., L/2, L/4, L/10, etc.). Which depth range is typically considered deep enough that bottom effects on waves are small? • Think about why the exam mentions a single amplitude roll angle of only 3°. Does this represent a relatively stiff or tender unit, and are you likely more concerned with avoiding resonance in shallower or deeper water?

✅ Before You Answer

• Make sure you convert the roll period (10 s) into an estimated wave length in feet before looking at the choices. • Check which answer choices represent water depths that are small vs large fractions of the wave length you computed. • Verify that the depth you are leaning toward is consistent with typical criteria (e.g., wave motion not strongly influenced by the seabed) used for deciding when it is acceptable to go on location.

Question 1 of 27070

The COASTAL DRILLER is experiencing a single amplitude roll angle of 3 degrees and a roll period of 10 seconds. What is the maximum water depth that can be used for going on location?

45 feet

95 feet

145 feet

245 feet

Question 1 / 2707066636ee728f7522a1c517722

Question 1 of 2707066636ee728f7522a1c517722

The COASTAL DRILLER is experiencing a single amplitude roll angle of 3 degrees and a roll period of 10 seconds. What is the maximum water depth that can be used for going on location?

Back

Question 1 of 27070

The COASTAL DRILLER is experiencing a single amplitude roll angle of 3 degrees and a roll period of 10 seconds. What is the maximum water depth that can be used for going on location?