Research Of Superstructure Complete Assembly Lifting Technic

With the competition of the international shipping becoming more and more vehement, it makes higher requests for the bigger ships and the speed of shipbuilding. One of the main factors that restrict the speed of shipbuilding is the percentage of the outfitting, as the superstructure is the biggest module of the outfitting, improving its percentage of the outfitting before the assembly lifting, will no doubt enhance the produce efficiency, shorten building period, and reduce the shipbuilding cost. But the bigger ship makes the scale of the block and the weight of the superstructure become bigger and bigger, also makes the intensity become weaker. It makes the superstructure assembly lifting become more and more difficult. So it is very important to analyse the superstructure before the assembly lifting systematically.The main clue that impenetrates this thesis is the whole superstructure assembly lifting. The emphasis and nodus of this thesis are analysing the stress and distortion of the assembly lifting during the whole process applying the Finite Element technic,and deepening the working order and the pallet management of the superstructure in order to enlarge the percentage of the outfitting. This thesis researched the five-layer superstructure complete assembly lifting of 108000DWT oil tanker, which is one of the main ship types of Shanghai Waigaoqiao Shipbuilding Limited Company. The paper analyses all kinds of states of the superstructure during the lifting; finds out the easily distorted parts by calculating; and for the areas which have bigger distortion, it makes reasonable modification or reinforce, optimizes the lifting project, ensure the quantity of the distortion within all demands of the specialty; and researches deepening the working order of the superstructure and the pallet management most completely under the condition of the lifting ability.The research of this thesis establishes the stable basis of theory and practice for our company to enlarge the percentage of the outfitting and put the complete superstructure assembly lifting in practice. The researching achievements of this paper are tested by a series of ships, and the effect is very evident. The superstructure building period has shortened from four months to now about forty days, viz. , the time is shortened by two-thirds nearly. This paper ensures all the superstructure work to be finished within fifty days after the ship undocks, which provides the conditions to enhance the speed of the whole shipbuilding in our company.