A lofty business

Pete lofting the frames from the offsets

After the big day yesterday, we woke to a dull and drizzly morning. While the rain is much needed, as Tassy is in the grip of a water shortage, it was a bit chilly for our un acclimatised Northern Territory bones. Deb decided to stay home to sort out our rego and licence transfers, and I elected to work inside the workshop and begin lofting the frames. Deb’s brother Russell, and his wife Jody have been excited and supportive about our project from the get-go and actively involved in helping us. They made the vacant space at the rear of their shed available for the build. Russell also insisted we store the flat-packs of expensive marine plywood in his adjoining workshop. As a experienced joiner and cabinet maker he was concerned that my original plan to store the sheets edge-on in our container, could lead to bowing of the sheets.

Lofting is an ancient art. Over thousands of years, shipwrights evolved ways to to convert 2D drawings into full scale 3D ships. In some cases models were hand carved, and scaled up. From gridlines, a table of offsets is calculated. This is the “DNA code” that determine the final shape of the vessel. The shipwrights would loft the offsets by drawing them full size onto the floor of the workshop. Then frames(or ribs) would be steam bent and offered up until they matched. In the case of Selah, the designer Peter Snell, supplied the table of offsets in the plan set. These determine the shape of the frames that we will mount on the strong-backs. It was exciting to be working on actual boat building, rather than site preparations. Meticulous, detailed and throughly enjoyable work, I felt connected with the generations of shipwrights that had gone before. Traditional shipwrights these days are few and far between. Once however they were the NASA engineers of their day. Here is a link to craftsman Louis Sauzedde who has posted a number of videos on Utube :

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