Function Of Semi-Submersible Heavy Lift Vessel And Heavy-lift Transportation

According to the development of global economic integration, especially the development of oceanographic engineering, semi-submersible vessel is leading a more and more advantage in ocean engineering and playing a more and more important character in the ocean transportation market. Driving the jack-up platform and the oil-field jacket launching into the sea, Transporting large steel structures of sea-crossing bridge and contain crane, and dispatching the caissons, engineering vessels and dredges, all of the projects above could not be separated with semi-submersible vessel.Semi-submersible vessel is a kind of vessel with high technology content and high value additional. In case, the cargo that transported by semi-submersible vessel is also with great value (even though much higher than the semi-submersible vessel itself). Because the cargo is usually with great size and great weight, the center of gravity will also be high and the area affected by wind will also be large. In this case, the stability of our semi-submersible vessel will be sensitive by wind and wave. It will be so easy for the cargo to move or heel during long-distance transportation that the performance of the semi-submersible vessel should be considered to prevent the vessel and cargo from dangerous accident.According to the research of the ship type, the stability and the structural strength of semi-submersible vessel, this paper analyses the difficulty or characteristic of the semi-submersible heave lift vessel on function calculation exhaustively. For example, how to plan the loading capacity and the submerge depth legitimately, how to select not only ship’s main particular but also the ballast and position system. In additionally, measure control on light weight and centre of-gravity position of light-ship. Analyses the relation of the projection of loading is realized about the reserve buoyancy and weight & centre-of-gravity position, as well as the rules and regulation of suitable on intact stability and severe wind and rolling, damage stability, submerging work stability. Design the operation procedure of submerging. Some questions are discussed exhaustively in the hull construction strength, which are affected the ship’s function. Such as the selection of hull skeleton, design of the middle section, calculation of stilling bending moments and stilling shear forces, as well as wave bending moments and wave shearing forces.In additionally, by the experience of semi-submersible vessel’s transportation, this paper will also show the operating methods and procedures of different conditions to ensure the safety of the vessel.