User:John Hutton/Triple plank kauri

Triple plank Kauri
Triple plank Kauri is a yacht hull construction method unique to New Zealand. Kauri is a native timber of New Zealand and its exceptional durability and strength makes it ideal for yacht hull construction. The triple plank method utilises three strips of the timber each usually about 3/4 to 1 inch thick an in various widths up to 4 inches. To make the skin of the hull the three strips of timber are "nailed" together using copper nails or roves.

The hull is built upside down over a sacrificial former usually the two inner layers of Kauri are laid about 45 deg to the horizontal and the final outer layer horizontal. The construction method is similar to double diagonal carvel, but wheras that method uses a tar soaked membrain between the two skins to prevent seepage the Triple plank method has no intermediate material between the layers. There are no internal ribs used in the hull but several longuerons run from fore to aft.

The final result is a very strong moncoque shape, the Kauri timber is highly resitant to rot and marine borers. A well maintained triple plank hull will have a service life of over a hundred years. --John Hutton (talk) 14:15, 27 October 2009 (UTC)