Technology Research And Application On Reducing The Sighting Conditions Of Shafting During Shipbuilding

In recent years,the world's major shipyards has faced a serious problem that they can not undertake the orders in time because of the long construction period of ship.Many small yard has closed down due to less orders.It reminds shipbuilding enterprises: it is imperative to reduce the shipbuilding period,especially reduce the shipbuilding period in ship dock,because of the dock is one of the most important resource.At present domestic ship launching is limited by the shaft installed in the dock.Shipyards,Japan and South Korea have finished the work of shaft-sighting,boring the stern tube,shaft installation and the main engine installation after the third platform finished of the engine room,in the early 90 s.And the shafting installation and rudder system are constructed separately,and don't have to wait until the stern hull structure forming.The construction way greatly reduces the sighting conditions.This method does not need open hole in the engine room,ensure the platform outfitting integrity,the superstructure can also be welded in advance at the same time,and realize pulling the cable,power of motor vehicle,etc.So it is necessary to do research in reducing the sightingconditions.The paper is mainly do research in reducing the sighting conditions on basis of two type of ship as container ships and bulk carrier.Mainly do research in the factor that affects the shaft sighting.We measure the data and make the conclusion.Firstly,measure the baseline and analyze the block weight affect to the baseline.Secondly,measure the diameter of the stern tube analyze the block and equipment weight affect to the shaft line,before and after the change of the stern tube shaft diameter.Thirdly,measure the center of the sealing plate and rudder line,analysis of rudder horn and engine block assembly effect on rudder system;Fourthly,measured the shaft line at various temperatures,and analyze the best sighting time.Ahe paper provides a large amount of data on reducing the sighting conditions and provides a reliable way to shorten the production period in ship dock.