AMOCO - KING TRUSS-SPAR
Gulf of Mexico, USA - 1998

Platform
The King Spar was planned as the world’s first composite spar, with an upper hull section mated to a truss section below. The water depth of 5,400 feet, made the structure the deepest yet in US waters. Following the BP merger with Amoco the development plans were shelved.*

Challenge
The King Spar concept involved a unique combination of spar technology and fixed jacket technology. Little or no codified design guidance was available for many of the complex connection details.

MSL Scope
MSL were retained by Amoco to provide an independent review and independent verification of critical connections, including the hull-to-truss connections, the hull-to-deck connections and heave-plate and bottle connection details. MSL also developed acceptance criteria for hot spot stresses and a practice for use by the designer for determining stress concentration factors from finite element analyses. MSL were commissioned to undertake a fitness-for-service assessment of the facility to assist life cycle cost minimization.

Benefits
The benefits of the various studies were reflected in savings in material, fabrication times and PWHT requirements. The work also assisted Amoco in obtaining class approval for the connection designs. An additional benefit, if completed, would have been the application of the fitness-for-service assessment to future inspection planning.