Minimum slamming pressure on flat cross structures (DNV-GL)

Discussion in 'Class Societies' started by Roni, Aug 5, 2020.

  1. Roni
    Joined: May 2020
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    Location: Brazil

    Roni Junior Member

    Hi there,

    I'm working out scantlings for a 10 m catamaran in accordance to the 2018 DNVGL rules for HSLC (high speed light craft). For flat cross strucutres (the bridgedeck) there is a minimun pressure required on DNVGL-RU-HSLC Pt.3 Ch.1 pg 27 as follows:


    That is a quite high minimun pressure. I've checked some other rules: the 2015 DNV, 2002 GL, 2002 BV and 2020 Lloyd's. None require to apply such a high minimun pressure. I was just wandering why such a disparity between the rules

  2. Ad Hoc
    Joined: Oct 2008
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    Location: Japan

    Ad Hoc Naval Architect


    You're only looking at half the picture.
    Each Class society has its own method of arriving at pressures for scantlings. If you compare just those pressures, you'll find discrepancies...
    But once you design your structure to satisfy the pressure and minimum requirements, you will discover that the final scantling you use, is pretty much the same which ever Class society you use.... except for BV.

    Thus do not focus on the absolute pressures... you need to compare the actual structure using each Class rule.
    bajansailor likes this.
  3. Alik
    Joined: Jul 2003
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    Location: Thailand

    Alik Senior Member

    DNV-GL HSLC 2018 rules are not suitable for small craft such as 10m catamaran, the design accelerations and pressures are too high. Advice: find GL HSC rules 2012, this is the most reasonable method for small craft, especially in composite.
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