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Ship launching with Air bags

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    Ship launching with Air bags

    The simple way to launch ships today is by using Air bags. No need for anything but a slope with reasonably hard soil and reasonably clean.

    The Chinese company that has developed this technique has put out a YouTube video to show how it is done:http://www.youtube.com/watch?v=cZJzW...eature=related

    No need for slides and nothing welded to the ship's hull, which need to be removed in dry dock afterwards: http://www.youtube.com/watch?v=vXjbX...eature=related

    The vessel can be almost fully completed on dry land:
    http://www.youtube.com/watch?v=8_wPg...eature=related
    and go on sea trails shortly after launching.

    I had a link to a video of a ship being launched off a sand bank, but it appears to have been removed from the net.

    I also have a video of a large (146 m. loa) Construction Barge being launched at Bintan, Indonesia, but I don't know how to get it posted here. Here is some pictures from that launch, however:

    The barge is still on flat ground, before being shifted to the launching ramp:





    #2
    Being shifted to the Launching ramp during the night:




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      #3
      And here goes:
















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        #4
        And here it is afloat:


        But the "Sausages" are still popping out from under the hull:


        The tugs have taken control:


        Being moved alongside the wharf at the yard at Bintan, Indonesia:


        The DBL NorCE Endeavour is now almost completed at a yard in Singapore:

        It is the one on the inside of Global 1201, with a 1,400 tons SWL Crane installed. (Blue)

        I don't know if this method of launching has been used outside Asia, but it is becoming the norm here. Very simple and efficient.

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          #5
          Very impressing! Thank you for this exiting photo report!!!
          Lofoten '07 ...... Nordnorge '11

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            #6
            When you think you know everything in the world, we are smacked back in place learning something new.

            Thanks for an interesting report!
            With best regards from Jan-Olav Storli

            Administrator and Owner of CaptainsVoyage.
            Main page: http://www.captainsvoyage.com

            Surround yourself with positive, ethical people who are committed to excellence.

            Comment


              #7
              Here are a couple of videos of ships launching with airbags.



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                #8
                It's so simple. I wonder if the ship sits on blocks and they put the air bags underneath deflated then put air in the bags to lift the ship off the blocs or if the ship is lowered down on to the already inflated bags?

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                  #9
                  As an engineer being engaged in marine airbag engineering projects ,I would like to answer this question. To lift ship off blocks, people put deflated airbags underneath the ship first ,then inflate airbags to lift ship. In fact the lift work often was executed from the bow to stern step by step and at that time the ship was pulled tightly by steel ropes from winches.

                  Place airbags
                  Last edited by Eversafe; October 23rd, 2010, 17:34. Reason: add a picture

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                    #10
                    An interesting photo. Do you think they have enough anodes?

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                      #11
                      I don't know if anodes are enough. Since new built vessels must get the society inspection certification before launch I think the anodes should be ok.
                      Regarding airbag launching, there is an illustration of airbag' pressure change curve during launch period which maybe useful for people to research the safety of launch.
                      The link: http://www.eversafe-marine.com/en/technology.aspx

                      Comment


                        #12
                        Originally posted by Eversafe View Post
                        I don't know if anodes are enough. Since new built vessels must get the society inspection certification before launch I think the anodes should be ok.
                        Regarding airbag launching, there is an illustration of airbag' pressure change curve during launch period which maybe useful for people to research the safety of launch.
                        The link: http://www.eversafe-marine.com/en/technology.aspx
                        During a launch using airbags a few days ago an accident happened. Not directly because of the launch, which was done very slowly and safely, but when they maneuvered the dredger alongside. After having spent more than an hour watching the dredger moving slowly down the slop I decided to go for lunch. That's when they finally "let her rip".

                        After she was afloat one of the airbags were still under the hull. It came shooting to surface as the dredger approached the wharf, jumped up on the wharf and hit a worker who was there to help in the mooring operation.

                        I don't know if he was killed, but he was badly hurt and bleeding profusely from the ears and mouth when he was put in the ambulance.
                        I'll post some stills from the launching, as the video is like watching paint dry.

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                          #13
                          The airbags shoot to water surface most happens at the "stern floating" stage for narrow bow ship launching. Such ship often has more weight at bow. I experienced such accident once. Fortunately nobody got hurt but a cabin at wharf was shot.
                          To aviod this, people can set wide isolated area especially for the "bow floating" position. And use ballast water to adjust the gravity center of launched ship is the essential solution as far as I know.

                          Comment


                            #14
                            Originally posted by Eversafe View Post
                            The airbags shoot to water surface most happens at the "stern floating" stage for narrow bow ship launching. Such ship often has more weight at bow. I experienced such accident once. Fortunately nobody got hurt but a cabin at wharf was shot.
                            To avoid this, people can set wide isolated area especially for the "bow floating" position. And use ballast water to adjust the gravity center of launched ship is the essential solution as far as I know.
                            Accounting for the number of air bags and ensure that none is left under the hull before trying to moore the ship alongside is also an important aspect.
                            If you look at the pictures from the NorCE Endeavor launching, you can see how the Airbags jumps just about clear of the water. This is a wide barge, not a narrow bow ship.
                            Here is a few pics of the dredger that was launched a few days ago. Unfortunately I didn't get any of the "fast" bit of the launch, only the controlled bit when the bow restraining wires were still in place and the winches used to slowly move her down the ramp.

                            Here it is on flat ground 26. 10.2010:






                            The next morning she had been moved to the sloping ramp, awaiting high tide for launch:


                            Tide raising and the ship moving ever so slowly down the ramp, controlled by two winches:




                            The watching crowd is getting restless, it is lunch time:


                            If you see it moving, it is too fast:


                            Short video. Tugs standing by:

                            My battery and patience run out. I went for lunch, only to see through the Mess Room window that the dredger was moving faster.
                            I did not seen the accident, only noticed an ambulance moving away and was told that one man had been hit by an Airbag while helping to take the ropes to moore the dredger.

                            She is afloat:
                            Last edited by ombugge; October 30th, 2010, 10:13.

                            Comment


                              #15
                              Thank you for your nice pictures. They are impressive.
                              These two barges are both launched with two row airbags, so airbags jumped out of water when the bow was afloat.
                              For my personal view, lengths of airbags for NorCE Endeavor launching are short. if people can use longer airbags and place them in two rows but overlap at the center of hull it will be better for safety of launch and hull structure.

                              Comment

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