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Question about ship launches

Discussion in 'Technical Discussion' started by Blue Ghost, Feb 24, 2016.

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  1. Blue Ghost, Feb 24, 2016
    #1
    Blue Ghost

    Blue Ghost Member

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    Okay, so cruising YouTube I see a lot of ships launched from slips into water "the old fashioned way", on rails or rollers, and they make a big wake or splash or both.

    I'm just curious why boats are build like that instead of in dry docks, where once construction is done, you simply flood the dock and float her out.

    Is there some kind of safety issue with workers in dry docks? Fear of flooding or something?

    Thanks much for any response.
  2. K1W1, Feb 24, 2016
    #2
    K1W1

    K1W1 Senior Member

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    an above ground launching system is cheaper to build.
  3. Blue Ghost, Feb 24, 2016
    #3
    Blue Ghost

    Blue Ghost Member

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    Interesting. Thanks.
  4. Marmot, Feb 24, 2016
    #4
    Marmot

    Marmot Senior Member

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    Over the past 40 years or so most new shipbuilding yards have gone to graving docks for building and "float out" as it allows the ship to be built on a level surface and doesn't risk damage to the ship or other nearby facilities during launch. The ease of construction and access saves a fortune compared to side launch or the traditional sloping greased ways.

    In Japan and Korea, several yards have graving docks large enough to assemble more than one ship at a time, insert a cofferdam between them and launch the ship closest to the gate. They assemble them from "blocks" built at other places in the yard and welded together in the dock. Most cruise ships are built this way, in a dock, under cover in controlled conditions.

    The old style sliding down the ways is going the way of wooden boats.
  5. chesapeake46, Feb 24, 2016
    #5
    chesapeake46

    chesapeake46 Senior Member

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  6. Rodger, Feb 24, 2016
    #6
    Rodger

    Rodger Senior Member

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    Launching 730 ' M/V Patterson in Collingwood Ontario Canada
  7. Marmot, Feb 25, 2016
    #7
    Marmot

    Marmot Senior Member

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    Launch.jpg Float out launches also reduce spectator participation. This is the launch of a ship in La Ciotat. There is a great video of the event someplace, I saw it in the shipyard museum but cannot find it online ... it is an amazing few moments of suspense and hilarity.

    This is from the Musee Ciotaden
    Last edited: Feb 25, 2016