Thirty years ago, under the leadership of Chen Xingguo, secretary of the shipyard, a group of shipwrights who only knew shipbuilding and repairing did not hire engineers or bridge building drawings. They relied on the memory of cable-stayed bridges in Changchun. A modern cable-stayed bridge with a span of 62 meters was built between Zhidao and Mantoushan Island. This is the first cable-stayed bridge in Zhoushan. Wang Mifa, the current director of the Changzhi Shipyard located on Mantoushan Island, said that when Shanghai was building the Nanpu Bridge in 1988, experts came here to inspect it.
The span of the bridge is 67 meters, and the north and south shorelines are 10 meters each. The bridge is pulled by eight 25mm steel cables on the left and right sides of the steel tower. The outer shell of the steel cables is coated with butter and wrapped in plastic cloth. The shore end of the tower is fixed with two 50mm steel cables. The bridge superstructure is welded from old railroad tracks. The bridge deck is 2.5 meters wide and consists of 134 five-hole cement boards each 50 centimeters wide and 240 centimeters long. This bridge was built more than 20 years earlier than the Taoyaomen Bridge, the Zhoushan cross-sea bridge that uses cable-stayed bridge technology.
This cable-stayed bridge is named "Changzhi Bridge" and connects Changzhi Island and Mantoushan Island. Mantoushan Island is the location of Changzhi Shipyard. Wang Mifa was already the deputy director of production at the factory. He recalled: There were more than 200 employees in the factory at that time, and the only way to get to and from get off work and to transport materials was by small sampans. When there were many people commuting to and from get off work, the employees rushed to get on board. Boats are often overloaded. When encountering high tide or low tide, when the current is turbulent and severely overloaded, accidents such as boat capsizing and passengers falling into the sea may occur.
The shipyard's materials can only be transported in and out by small sampans, which hinders the development of the factory. In order to improve the development efficiency of the shipyard and ensure the safety of employees. At that time, a group of leaders in the factory discussed and finally decided to build a bridge between the two islands.
Building a bridge has been decided. But everyone is just an expert at building ships. If they want to build a bridge on the sea, these skilled craftsmen can only look back and sigh. It happened that Chen Xingguo was on a business trip to Anji and discovered a cable-stayed bridge in the middle of a large stream. After returning, he summoned the backbone of the factory to discuss and determine the construction plan for the bridge. The shipyard immediately raised 40,000 yuan in funds.
After the funds are in place, shipbuilding materials are still a big problem. When building a bridge on the sea, we must consider tides, wind protection, and seawater corrosion. It is not safe to use ordinary materials. Moreover, materials were scarce at the time, so the shipyard had to prepare all the materials for the bridge itself. Wang Mifa followed Chen Xingguo to a foreign flea market and bought the rails that were replaced from the railway at that time as the bridge deck skeleton. But where to find the most critical material, steel cable? Wang Mifa said, "Fortunately, when the cable-stayed bridge was built in Anji, there were still some remaining German steel cables purchased, so we bought them all."
So, the only one who had ever seen a cable-stayed bridge was Chen Xingguo was responsible for the design, and shipwrights from Changzhi Shipyard collaborated on the construction. There was no lifting equipment and an iron hoist was used. The local method was to mount a horse and rent an old boat and throw it in the center of the harbor as a scaffolding. The bridge is a cable-stayed bridge with low anchors fixed at both ends. The steel towers at both ends are 15 meters high. Workers stand in the iron barrels and use iron hoists to pull the iron barrels to the top of the tower for welding. The welding of the main structure of the bridge deck relies on the movement of the construction ship and is welded piece by piece. In this way, without drawings or designs, and only by visual inspection, it took about 3 months to successfully build this cable-stayed bridge between the two islands.
Changzhi Bridge in Dinghai District
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