Retrofit technology for cutting and lengthening ships via dry-type trolley method

Abstract

The invention discloses a retrofit technology for cutting and lengthening ships via a dry-type trolley method. The technology is carried out by prefabricating newly-added sections by sectioning, arranging docking blocks, drawing lines on a ship body, strengthening the structure of the ship body, and cutting by sectioning. The technology comprises the following main steps of: controlling the docking precision of the ship; paving a combined-type rail, connecting and putting a combined trolley; precisely lying the ship on a keel block after the ship docks; arranging a thrust device; adding supports at the front end of a bow section and the rear end of a stern section of the ship; displacing the bow section; assembling the newly-added sections and folding the newly-added sections with the stern section; and precisely aligning, locating and folding the bow section with the newly-added sections. The technology is suitable for cutting and lengthening ships in any mold lines and tonnages and has the advantages of rapid folding speed, high firmness safety, simple and reliable process operation, short retrofit period and low cost. The folding and locating precisions are high, so that the precise displacement and aligned location of the bow section are effectively guaranteed and the folding precision reaches the level of a newly-constructed ship. On the other hand, the technology is less affected by the change of exterior environment factors such as weather, which is beneficial to the control of the docking period in enterprises.

Description

technical field [0001] The invention belongs to the technical field of ship repair and construction, and specifically relates to a technology for cutting, lengthening and refitting a ship by a dry-type trolley method. Background technique [0002] In order to meet the needs of the market and increase the capacity of the fleet, many shipowners have adopted the method of lengthening and refitting ships with short refitting periods and low refitting prices to upgrade existing ships in operation. Over the years, ro-ro ships, container ships and various special ships have always been the "double-high" ship repair products of ship repair companies. However, the cutting and lengthening of these ship types is technically difficult, requires high construction precision, and complex process operations. It includes high-end shipbuilding technology and domestic advanced ship repair technology and technology. It is a highly comprehensive and technical ship repair project. There are two...

AI Technical Summary

Problems solved by technology

This process has the following disadvantages: ① the required pulling force is very large, and the ships that can be pulled at present are all below 3,000 tons of load; ② the deviation correction is not easy, and the accuracy is greatly limited. The main equipment used is rails, traction cars and pulley blocks. This rail directional pulling method is difficult to correct the deviation, and the deviation of the ship's pier is also large, resulting in a large error after docking, which is not suitable for ship refitting with high precision requirements; ③The whole process operation is more complicated and the cycle is longer

However, this technology also has shortcomings. ①The safety is slightly poor. Because the floating state of the first stage cannot be accurately calculated, it may capsize when floating and shifting. A foreign shipyard uses this sinking and floating method to cut off the ro-ro ship During the lengthening and refitting, an accident occurred where the bow section capsized at the dock gate; ②The range of safe and applicable ship types of this process is relatively narrow. The risk of capsizing of the bow section is relatively high when refitting other complex-shaped ships; ③ Due to the difficulty in fine-tuning the floating state of the bow section, it is difficult to ensure the accuracy of hull closing and alignment. The three-section hull Folded lines or dislocations occur frequently at the closing place, which affects the accuracy of ship refitting and construction and the appearance; ④The entire refitting process is greatly affected by weather conditions, especially the ship type with a relatively large upper wind area. Big

⑤ It takes 2 to 3 docking times to complete the refitting project, which increases the refitting cost and lengthens the refitting cycle

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