The Thirteenth Improvement

Consists of an improved treenail for fastening the outside and inside planks to the timbers of ships and other vessels -- and which I call "Clip treenail."

Its shape is shewn by Figure 13 -- by which it will be seen, that in addition to an enlarged head, it has towards its end, a shoulder all round the wood, which shoulder is form [sic] by tapering the treenail for a short distance between the point and the head. When the treenail is driven into a plank and timber, the shoulder prevents the treenail from starting away from the timber, and as the enlarged head prevents the plank from starting away from the timber, the plank becomes firmly clipped to the frame.

Nothing tends more to the permanent strength and tightness of a ship than the close adhesion of the planks to the timbers, and the fastenings ought therefore to be of such a kind, as that neither the operation of caulking nor the straining of the vessel shall at any time, or in any degree, force the planks away from the timbers. The diameter of the treenail is the same near the end as in the middle, and to insure the shoulder holding properly, it must be turned in a lathe or other machine, and so that the shoulder shall be at a sharp right angle with the treenail hole -- and, when driven as usual into a smaller hole than the size of the treenail, the point of the shoulder shall have a tendency to cut into the timber, and thus prevent the treenail from ever starting away from the timbers.

The clip treenail will probably draw the plank closer to the timbers than a common trenail, altough the latter should go through both plank and ceiling.

When the outside plank is not drawn close to the frame, the friction of the bilge water diminishes the size of the treenails, and thus the fastening becomes very insecure.

Before driving any treenail, I recommend the hole as well as end of the treenail to be smeared with hot vegetable tar -- or if just before driving the treenail it were immersed in hot tallow, or hot linseed oil, the treenails would be much more durable than at present. [page 76]

To receive the enlarged head of the treenail, the outer part of the treenail hole in the plank may be trifingly enlarged with a cooper's bung-borer.

The rounding of the treenail head is to prevent its splitting while driving.

Regarding this improved treenail, I make no claim for either the enlarged head or the turned shoulder separately, but what I do claim is, the above particularly described clip treenail with the turned shoulder, combined with the enlarged head, for fastening vessels' timbers and planks together.

In driving long treenails, it has been found that they frequently split and break, and that, to ensure their being driven, they must be of less diameter than short treenails for the same size auger-hole. Hence long treenails necessarily become a very bad fastening -- especially with reference to that very important point in shipbuilding -- the drawing the plank close home to the timbers. [page 77]

Shipwreck and Collisions at Sea greatly prevented by Christophers' Patent Improvements in Naval Archtecture. With four plates.
London: J. Olliver, 59, Pall Mall; P. Richardson, 23, Cornhill. Liverpool: Deighton & Laughton. M.DCCC.L. 8vo, (4), 112 p, 4 pl.

Transcribed by Lars Bruzelius

Sjöhistoriska Samfundet | The Maritime History Virtual Archives | Shipbuilding | Fastenings.

Copyright © 1996 Lars Bruzelius