This paper presents a comparative study of the numerical simulations and the field measurements for a 23,322Te large jacket launch into a water depth of 190.2 meters in South China Sea. The sensitivity simulations demonstrate that the friction coefficient between jacket launch cradles and barge launch skidways is the dominant factor in the jacket launch simulation. This domain factor plays the most important role in the jacket launch. It recommends that a friction coefficient ranging from 0.03 to 0.08 should be used in the sensitivity analysis of jacket launch in the future. This comparative study not only ensures the integrity of the large jacket and the launch barge during launch, especially at tipping, and a clear safe separation between launch cradles and rocker arms, but also benefits safe launch operations by calibrating the numerical modeling in the launch simulations of future jacket installations.
A comparative study has been conducted to investigate the launch simulation and field measurement of an 8-legged jacket launch into a water depth of 190.2m in South China Sea. The factored launch weight of Pan Yu 34–1 jacket is approximately 23,312Te with a total height of 203.5m. The world's second largest T-shaped launch barge "Hai Yang Shi You 229" was selected to launch this large jacket. Refer to Fig. 1 for the views of the PY34–1 jacket launch. The comparison of the jacket launch simulation and field measurement is used to calibrate the jacket launch simulation predicted by the computer software MOSES and also to study the uncertainty and inaccuracy of the T-shaped launch barge due to its shoulder effect of midbody transition.
Two independent sets of Inertial Navigation Systems (INS) and Global Positioning Systems (GPS) were installed on the two launch cradle legs to measure the trajectory motions and accelerations of the launch jacket, thus ensuring a 100% redundancy and a double check with each other. A third GPS system is also used to measure the motions and accelerations of the launch barge. In addition, optical fiber strain gauges were installed on both the rocker arms to monitor the reaction loads acting on the two rocker arms from initial launch, tipping, until separation. A parametric analysis of the jacket launch simulations was performed by varying the friction coefficients between launch cradles and launch skidbeams, the jacket weight, the offset of jacket center of gravity, the barge drag coefficients due to the T-shaped hull, etc. The comparison of the numerical findings and the field test results is then used to investigate the impact of the T-Shaped launch barge and other potential influence parameters, and therefore determining the dominant parameter of interest.
