Study on the design of a model experiment for deep-sea S-laying

As a primary device of the S-lay technique, the stinger is used to protect the overbend section in a pipeline. It is difficult to determine the design loads acting on the rollers during the dynamic pipelaying condition using numerical methods alone. Instead, a test model is used to analyze this complex problem. This paper introduces some similarity criteria based on the dynamic similarity of a stinger, a pipeline, and a vessel. Then, the stinger of the first pipelaying crane vessel in China, “HYSY201”, is modeled with these similarity criteria. The loads for the stinger׳s structural design and movement mechanism in the off-design conditions are simulated, producing some useful conclusions and suggesting that local reinforcement of this stinger be performed. The vessel recently began its first deep-sea pipelaying project in Liwan in the South China Sea. Thus, the model method proposed in this paper is effective and could be used to design and test other articulated stinger structures rather than relying on engineering heuristics.