Pipelay vessels, such as the Hai Yang Shi You 201, have been seriously affected by large period swells in the East China Sea, where the roll amplitude is extremely large for normal pipe lay. Two conditions that can generate dramatic rolls, namely, parametric and synchronous rolling, were analyzed theoretically in this study. Model tests were also performed on the pipelay vessel Hai Yang Shi You 201 with course angles of 0, 30, 60, and 90°in swells of varying periods and wave heights to examine the aforementioned effect. The test data proved that drastic roll is not caused by parametric rolling, when the pipelay vessel is hit by a swell whose period is equal to approximately half of the natural rolling period. Results showed that drastic roll is instead caused by synchronous rolling, which occurs when a vessel is hit by a swell whose period is close to the natural rolling period. Combined with meteorological data, the results can serve as basis for the selection of a construction climate window.

Included in

Engineering Commons