A treenail is a wooden peg or dowel which can be used to fasten pieces of wood together, it is a traditional method, usually a well seasoned treenail is driven into a hole, when it takes up water, it will expand and 'grip' its position. Simple but quite effective fastening of old.
It was considered suitable use in the Grayhound project and would be used to join frames together, and planks to the deck and the hull. It was deeded a variable method against metal fastening due to their increasing cost and the use of oak that was a waste product to make the treenails.
There are 3 short videos:
Procedure explained through the use of computer aided design and captions from the boatbuilder, as discussed in the accompanying video clips.