Calculation on Refloating a damaged ship with salvage pontoon

Abstract

Abstract Refloating a damaged ship with salvage pontoon can be very complicated. In the calculation process of traditional pontoon salvage for shipwrecks, the calculation of inflation time, analysis of pontoon motion and intelligent control are mainly studied. When the pontoon is inflated, the volume of gas in the pontoon will change with the change of time and temperature, which will affect the accuracy of salvage measurement. In this paper, According to the theory of heat conduction, a mathematical model of gas volume in pontoon varying with time and temperature is established, which is beneficial to getting the buoyancy and stability of ships.Through the simulation, the refloating process of a damaged ship with salvage pontoon was researched. Computation result shows that shipwreck with many pontoons sunk in the water totally of the preliminary stage, since the stability of the shipwreck is poor, the aeration rate in the pontoon should be calculated accurately to prevent the capsizing of the ship. As the draft of the wreck decreases, the stability of the hull increases gradually, which is beneficial to the process of lifting and floating. The change of pitch angle is small in the course of buoyancy, but it has obvious influence on the buoyancy distribution of ship hull. The position of pontoon has a great influence on the distribution of shear force and bending moment of ship hull. Relevant measures should be taken to reduce the damage to ship hull in the course of buoyancy.