HSC Code - formula for accelerations

Discussion in 'Class Societies' started by Alik, Nov 4, 2024.

  1. Alik
    Joined: Jul 2003
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    Location: Thailand

    Alik Senior Member

    Interested in source of formulas for gcoll collision accelerations from HSC Code.
    Probably there were some publications with background study, to introduce the formula. Any idea?

    Reason: we need to study how this formula is suitable for small craft.
     
  2. Ad Hoc
    Joined: Oct 2008
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    Location: Japan

    Ad Hoc Naval Architect

    There is a mixed history behind all this.

    It first started with the Apollo Jet accident in HK in 1989. Apart from the findings requiring an FMEA for all vessels, structural implications were also discovered.
    I was initially on the Australian and then later the UK IMO's committee investigating this and attributing a "value" in terms of accelerations for such incidents.
    That was back in the early 90s.

    There were endless debates and suggestions put forward. None were conclusive, and it became a mixed bag of compromises to arrive at "some" solution that would be kind-of acceptable.
    It did have its flaws though and produced erroneous results for some vessels. Our 45m high speed catamarans yielded higher Gcoll values for a 20knots version compared to one of 45knot versions.
    It was not ideal, but served a function attributed to the safety of heavy mass items onboard that could break free during a collision or grounding.

    This was further exacerbated in with the grounding of Condor II and then also the St. Malo accident, that added slight changes in the newly formulated 2000 code - as well as improved damage stability. .

    Unfortunately all the data and papers I had on this new introduction have been lost - since it was some 30 years ago now.
    But I doubt very much they would give you any insights other than it is a poorly crafted formula, but serves a purpose, and no other alternative has been put forward that improves it.

    Bottom line is, it is basically about a high speed collision with an immovable object of 2m high, and then how much deceleration is experienced. And thus, apply this deceleration value to major heavy items onboard to their seatings to ensure they do not break free under such conditions.
     
    bajansailor likes this.
  3. Alik
    Joined: Jul 2003
    Posts: 3,079
    Likes: 372, Points: 93, Legacy Rep: 1306
    Location: Thailand

    Alik Senior Member

    Thanks AdHoc, this helps. I also feel the formula is a 'compromise'.
     
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