Marine Airbags: Innovative and Versatile Marine Tool (part 1)

Introduction
Marine airbags are widely used in China for ship launching ,caisson conveying and marine salvage nowadays. It is estimated that more than 80 percent new built ship whose DWT below 60,000 and about 50 percent caisson fabricated for gravity quay are launched by marine airbags.Not only in China but also other Asian countries marine airbags are acknowledged as the powerful and versatile tool for marine works.

The history of marine air bag dates back to 1990s. A Chinese ship repair and building shipyard launched a 60 DWT tank barge with marine airbags on January 20, 1981 and it is known as the first use of marine airbags. The invention of marine airbags was expected to develop a flexible, less limited ship launching method.

Over the past twenty years, marine airbags have made great advancements in the manufacture and application. The first generation marine airbags employ rubber dipped canvases as reinforcement material and two cone-shaped ends are stuck to the chamber trunk. Now the top marine airbags are seamless and their performances are about 15 times of the first generation with the same specifications. Regarding the launching/landing technology, marine airbags have also achieved a significant leap. In the beginning, only small and flat bottom ships located on a fabricated slope could be launched with marine airbags. Now this technology is more flexible and less limited by the ship and landform. The DWT of launched ship reached 55,000 and launching ramp can be aclinic. Not only for ship launching marine airbags are widely used for heavy conveying also. Marine airbags contributed much to the success of famous Nanhai No.1 ancient ship salvage project. The 4,800 tons cassion which hold the invaluable ancient ship landed from the semi-submersible barge and transported to the museum named Crystal Palace riding on 16 pieces marine airbags.