To educate everyone on the use of air bags as a cost effective technique used for ship launching, we reached out to Song Tao of Qingdao Evergreen Shipping Supplies Co.,Ltd. Let’s here what he has to say…

What were the first uses of air bags in the launching of ships?

The history of marine air bag ship launching dates back to 1981. Xiao Qinghe ship repair and building shipyard, located in Jinan city of Shangdong Province, launched a 60 DWT tank barge with air bag suspension on January 20, 1981. Seven air bags were employed in that project. One was 2 meters in diameter and 6 meters long and used for elevating.  The remaining six air bags were 0.8 meters x 6 meters long and acted as the rollers. The initial intention of that trial launch was to develop a prompt, less landform limited ship launching method for warfare purposes.

How has the technology advanced since then?

Over the past twenty years, the airbag ship launching system has made advancements in not only the air bag, but also the ship launching/landing technology. The first generation air bags used a rubber dipped canvas as a reinforcement layer to form the air chamber trunk. Two cone-shaped molds were then used to make the ends and everything was stuck together.

With today’s air bags, the whole-enlacing-technology used for manufacturing is done together.  Rubber dipped synthetic-tyre-cords are used as the reinforcement layers with the trunk and two cone-shaped ends made at the same time.  Everything is enlaced together, so the whole air bag doesn’t have any joints. Due to the development of rubber chemistry, the performance of the rubber employed in the latest air bags is highly enhanced and about 15 times of the first generation bag with the same specifications.

Regarding the launching/landing technology, it has also developed. In the beginning, only small and flat bottom ships located on a fabricated slope could be launched with air bags. Now this technology is more flexible and less limited by the ship and landform. Now any type of ship with a DWT below 55,000 and in a place with enough launching space can be launched using air bags. The launching slope even can be aclinic.  It has really developed into a cutting edge technology for launching ships, and especially useful for some marine emergencies. [Continue Reading →]

MarineBuzz brings us photos of the M/V Bohai Challenge, being launched on what appears to be Yokohama Fenders (official they’re not Yokohamas). They tell us;

Qingdao Yongtai shipping supplies co.,ltd has come out with a novel product called Intense pneumatic tire for ship lifting, loading and floating. These highstrength pneumatic tubes are useful in cargo boat launching and landing, clog lifting and moving, sunken ships salvaging and stranded boats saving. The product is suitable to launch ships up to 7000 tons.

CLICK HERE for more photos from Marine Buzz.

Also, in researching this post, I came across an excellent transcript from a Nautical Institute presentation by Captain Eric Southworth, Director of FenderCare. He tells us;

Originally, Japanese ships used dead whales as large fenders. They were replaced after WW2, when the Japanese tyre manufacturer ‘Yokohama’ was asked to come up with a suitable man made alternative, hence the birth of “‘Yokohama” fenders. Before 1975 wheel type fenders were commonly used in positions 2 & 3, with “Yokohama “pneumatic fenders in positions 1 & 4. (All four positions are along the parallel midbody). Smaller secondary fenders may be used to protect the bow and stern plating from inadvertent contact during mooring and unmooring.

Read Captain Eric’s full transcript on fender history, use and maintenance HERE.