Surf-riding/broaching is one of the five stability failure modes newly included into the Second Generation Intact Stability Criteria by the International Maritime Organization. It is considered to be the most complex one among the five failure modes due to its strong nonlinearity and chaotic characteristics, hence having high academic research value. This paper introduces the researches related to the surf-riding/broaching in recent years, elaborates the research progress of the theoretical prediction, numerical simulation, model test and specifications, as well as the research developments concerning the influence of the surf-riding/broaching on the ship design and ship operation. The key problems that have not been fully solved and the bottleneck technologies that need to be broken are analyzed based on the state-of-the-art of the ship surf-riding/broaching. It can provide references for the key research directions in the future.

The shuttle boat that navigates in the polar seas will encounter ice floes, causing the hull of the shuttle boat to collide and ride these ice floes. In this case, the motion of the hull and the interaction between the hull and the ice floes are issues that demand attention. The SPH-DEM method is adopted to solve this problem, which involves the interaction between the wave and the floating bodies, and the interaction between these floating bodies. The smooth particle hydrodynamics (SPH) is used to solve the wave motion, the interaction between the wave and the hull and the interaction between the wave and the ice floe. And the discrete element method (DEM) is used to solve the interaction between the hull and the ice floe. The pitch, surge and heave response of the hull and the ice floe, and the interaction between the ship and the ice floe are then calculated for four conditions of 0 degree and 180 degree wave directions and two longitudinal centers of gravity in front of and behind the mid-ship section, respectively. The results show that the hull and the ice floe connect closely with relatively consistent motion response amplitude and frequency when the center of the gravity is in front of the mid-ship section. The interaction force between the hull and the ice floe is dominated by the vertical component, and the stable time-averaged values of the vertical components corresponding to 0 degree and 180 degree wave directions can reach to 44.6% and 88.9% of the hull weight, respectively. However, the hull and the ice floe are free-floating when the center of the gravity is behind the mid-ship section, with stable time-averaged values of the vertical components approximately close to zero.

The influence of the shape and the size of the moonpool on the vulnerability criteria assessment of the parametric roll and the excessive acceleration in the second generation stability has been analyzed for a drillship. This article considers the drillship with three moonpools of different opening shapes and different sizes to verify and analyze whether the drillship meets the second generation intact stability criteria under development. The analysis results indicate that the variation in the shape and size of the moonpool can affect the parameters of the vulnerability criteria of the parametric roll and the excessive acceleration for the drillship. The drillship with the moonpool of the shapes and sizes considered in this study can meet the criteria requirements. It can provide reference for the design of the drillship's moonpool.

The automatic control model test platform based on 6-DoF optical system has been developed according to the model test demands for the automatic control of the two-ship lateral replenishment at sea. This article elaborates the composition, function and usage of this test platform, analyzes the characteristics and advantages of the platform compared with those of the conventional ones. The test platform is used to perform the two-ship lateral replenishment model tests in a large towing tank for the validation of the test platform. The current research lays a solid foundation for the application of the automatic control technology in the two-ship lateral replenishment at sea. It can also provide reference for the research and development of such advanced test platforms.