Which platform type uses a caisson as part of its foundation?

Which platform type uses a caisson as part of its foundation?

• A. Steel-Jacket platform
• B. Spar platform
• C. Caisson-type platform
• D. FPSO

Answer: (C)

This item tests how offshore platforms transfer loads to the seabed through different foundation systems. A caisson-type platform follows a gravity-based approach using a caisson foundation—a large hollow box or cylinder that is sunk into the seabed and ballasted to provide weight and stability. The caisson creates a big bearing area and resists overturning, so the platform structure sits on top of it and relies on that hollow chamber for support. This method is especially common in shallower waters or softer soils where a rigid, heavy base is practical. Other platform types use different foundations: jackets are steel frameworks anchored by piles, spar platforms rely on a tall, slender hull moored to the seabed, and FPSOs are floating vessels moored or dynamically positioned rather than fixed to a seabed foundation. Because only the caisson-type platform uses a caisson as part of its foundation, it’s the correct choice.

This item tests how offshore platforms transfer loads to the seabed through different foundation systems. A caisson-type platform follows a gravity-based approach using a caisson foundation—a large hollow box or cylinder that is sunk into the seabed and ballasted to provide weight and stability. The caisson creates a big bearing area and resists overturning, so the platform structure sits on top of it and relies on that hollow chamber for support. This method is especially common in shallower waters or softer soils where a rigid, heavy base is practical.

Other platform types use different foundations: jackets are steel frameworks anchored by piles, spar platforms rely on a tall, slender hull moored to the seabed, and FPSOs are floating vessels moored or dynamically positioned rather than fixed to a seabed foundation. Because only the caisson-type platform uses a caisson as part of its foundation, it’s the correct choice.