Contracts state reinforced hulls will use either diagonal iron strapping on the outside of the hull, or diagonal planking on the inside of the hull, or under the outside planking.
To strap a hull a wide band of iron called the wide plate is set at or slightly below the sheer line, starting a short distance from the stem to the stern post. The diagonal straps are riveted to this wide plate. The straps are arranged so they cross in the spaces between the frames where they're riveted together. The wide plate and the straps are dapped into the face of the frames as to be flush with the surface. Each strap is fastened to the frame with one countersunk head drift bolt.
Each strap being from 30 to 45 feet in length and 1/2 thick; it extends downward around the turn of the bilge and the ends bolt to the floor heads. At the turn of the bilge the straps are set deeper into the frame to allow for dubbing the frame flat under each strake of plank. This method saves the expense of hollowing out the fray of the planking to fit around the turn of the bilge. Sometimes in yards the foreman will dub the framing before the strapping is set in place to avoid daps being too deep and weaken the frames.
It has been done in yards to apply a diagonal sheathing to a hull under the planking. In other words, double plank the hulls. Like iron strapping where the wide band is set in place, in diagonal planking a band of chocking is used at the sheer and at the floor heads. This provides a continuous band to fasten the ends of the planking to.
Diagonal outside planking requires separate rabbets at the ends so the first planking will not lay in way of the final hood ends. Diagonal planking either in or out is always started at midships at a 45 degree angle with the keel.
On the outside, as the diagonal planking reach the ends of the hull, one edge will buck up and refuse to fay to the frame. This happens because the hull is longer at the top than along the keel and the top ends of the planking begin to fall behind the bottom ends. When this point is reached spiling in necessary. To fasten diagonal planking galvanized wire nails are used. These are short nails driven in at the extreme edge of the frames so as not to interfere with the plank fastening. This also serves the purpose to mark the location of the frames as they are now completely covered up.
In model building either Delrin strapping can be used or silver strips. Delrin or
silver will not turn the wood black in time.
{Dave Stevens}
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