John Knowles: An Inquiry into the Means which Have Been Taken to Preserve the British Navy, 1821

[p 66] Much discussion has at different times taken place, whether tree-nails or metallic fastenings are the best to be applied generally in ships, not only as increasing their strength, but prolonging their duration. Tree-nails were no doubt introduced from the consideration that iron is much subject to corrosion by the action of salt-water, and their use is nearly coeval with the British Navy; although official documents do not afford this information, yet mention is made of them in a paper bearing the date of the year 1552 …

The arguments advanced against the use of tree-nails are, that they are weak, (iron being eleven times, and copper six times, the strength of oak,) that they are subject to early decay, and by capillary attraction, water passes through them to the injury of the ships. Mr. Mackonochie in the year 1803, in the prospectus before alluded to, strongly reprobates their use. Notwithstanding the objections made to them, all the European(*) nations apply tree-nails, particularly in the bottoms of their ships, in a greater or less proportion; and when cut from good timber and properly dried, they have been found to be very durable. In order to facilitate their seasoning, it was the practice in the early part of the eigthteenth century, to boil them in salt water, but it is a custom not to be recommended, as it will weaken the fibres in the wood. If tree-nails be properly seasoned and then driven tight, they seldom leak, as moisture will increase their bulk, and the compression of the fibres prevent the introduction of water into the ships.
. . .

[p 73] Under all circumstances, it appears that the present method of fastening ships generally with though, wellseasoned tree-nails, with their ends split and caulked after being driven, and securing the butts of each plank with copper bolts well clenched, is liable to fewer objections, and more conductive to the durability of the timber, than any other which has been tried, or proposed to be substituted.

Footnotes:

*) The Dutch, during the seventeenth, and in the early period of the eigthteenth century, imported their tree-nails from Ireland. The oak grown in that country, being though and strong, was found to be best for the purpose.
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John Knowles: An Inquiry into the Means Which Have been Taken to Preserve the British Navy from the Earliest Period to the Present Time, Particulary from that Species of Decay, now Denominated Dry-Rot. Winchester and Varnham, London, 1821. 4to, 19x12.5 cm, xvi, viii, 164 pp.

Transcribed by Lars Bruzelius

Sj�historiska Samfundet | The Maritime History Virtual Archives | Shipbuilding | Fastenings.