Standards: Costly Hurdles or Vital Guidelines?

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point loads

The ISO 12215 standard gives designers and builders a detailed baseline for scan’tlings and specific guidance regarding material selection, workshop practices and structural details pertaining to hulls, decks, rudders and rigging for mono and multihulls. These scan’tling guidelines relate to specific skin pressures on the hull and stresses and strains that if not appropriately addressed can affect delamination and lead to structural failures. The codes are a complex amalgamation of data, but the University of Southamptons Wolfson Unit has recently developed a software program called HullScan’t that makes ISO compliance for builders and designers easier to work with. It auto-calculates the effect of thicker skins, added transverse and longitudinal support, and any upgrades in material choices, giving designers and builders a quick and user friendly means of determining what it takes to meet the structural requirements of A, B, C, and D vessel usage categories.

Though not perfect, ISO 12215 affords an analytical approach to engineering and boat building, and more importantly, boat buyers/owners get an idea of how strong the structure thats keeping them afloat happens to be. These are living documents and have and will be amended as new data and new materials enter the trade.

Key parts of ISO Structural Guidelines:

  • 12215-5 Hull construction and scan’tlings (monohull pressures on skin and calculating stresses);
  • 12215-7 Hull construction and scan’tlings (multihull version);
  • 12215-8 Hull construction and scan’tlings (rudders);
  • 12215-9 Hull construction and scan’tlings (appendages and rig attachment);
  • 12216 Hull construction and scan’tlings (strength of windows, port, deadlights, doors).
Darrell Nicholson
Practical Sailor has been independently testing and reporting on sailboats and sailing gear for more than 50 years. Supported entirely by subscribers, Practical Sailor accepts no advertising. Its independent tests are carried out by experienced sailors and marine industry professionals dedicated to providing objective evaluation and reporting about boats, gear, and the skills required to cross oceans. Practical Sailor is edited by Darrell Nicholson, a long-time liveaboard sailor and trans-Pacific cruiser who has been director of Belvoir Media Group's marine division since 2005. He holds a U.S. Coast Guard 100-ton Master license, has logged tens of thousands of miles in three oceans, and has skippered everything from pilot boats to day charter cats. His weekly blog Inside Practical Sailor offers an inside look at current research and gear tests at Practical Sailor, while his award-winning column,"Rhumb Lines," tracks boating trends and reflects upon the sailing life. He sails a Sparkman & Stephens-designed Yankee 30 out of St. Petersburg, Florida. You can reach him at darrellnicholson.com.