The ISO 12215 standard gives designers and builders a detailed baseline for scantlings and specific guidance regarding material selection, workshop practices and structural details pertaining to hulls, decks, rudders and rigging for mono and multihulls. These scantling 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 HullScant 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 scantlings (monohull pressures on skin and calculating stresses);
- 12215-7 Hull construction and scantlings (multihull version);
- 12215-8 Hull construction and scantlings (rudders);
- 12215-9 Hull construction and scantlings (appendages and rig attachment);
- 12216 Hull construction and scantlings (strength of windows, port, deadlights, doors).