Rudder coupling weld

Discussion in 'Materials' started by MikeJohns, Jul 31, 2018.

  1. MikeJohns
    Joined: Aug 2004
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    MikeJohns Senior Member

    Commercial coastal fishing boat 50 foot, complete rudder failure resulting in grounding and hull damage. Not a hard failure analysis !

    Flag rules ( NSCV) required the flange to have been fully welded to the shaft and annealed (both 316). It's a fillet weld and nothing more.
    Insurance company is not happy. So it'll sit for a while on the hard accumulating fees while the lawyers play the usual game.
     

    Attached Files:

  2. Ad Hoc
    Joined: Oct 2008
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    Ad Hoc Naval Architect

    I'd love to be a fly on the wall for this conversation!!
     
  3. MikeJohns
    Joined: Aug 2004
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    Location: Australia

    MikeJohns Senior Member

    Of course no one will "recall" who did what.
    It's an eye opener as to to check the rudder shaft it's usual to have the heel bearing removed, and drop the whole rudder and shaft attached to do a visual for corrosion, without unbolting the coupling. I'm presuming this was a repair/replacement at some stage by a machinist who doesn't normally work on boats.

    For ref for others I'll post a pic of what the prep should have looked like before multi pass welding turning and annealing, a much more expensive job when it's done properly:
     

    Attached Files:


  4. Ad Hoc
    Joined: Oct 2008
    Posts: 5,661
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    Location: Japan

    Ad Hoc Naval Architect

    Aahh..now that's a proper edge prep! :)
     
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