Rag Bolt (13A133)
"RAG BOLT, an iron pin, having several barbs..."
Falconer's Marine Dictionary (1)
A copper rag bolt recovered from a wreck site in Plymouth Sound. The bolt is marked on the head and shaft with a 'Broad Arrow' denoting that the fastening came from a vessel of the Royal Navy. It is curved possibly due to the wrecking incident or a result of the fastening. A verdigris patina is present on nearly 40% of the artefact. It has a round head, circular shaft and blunt end.
Falconer (1) notes that they are made of iron with no mention of copper, whereas Steel describes them as a "sort of bolt having its point jagged or barbed to make it hold more sercurely"(2). The ragging process is achieved by obliquely striking the shaft of the bolt to make raised indents or barbs, often using an axe. Ragging is also seen on other ships fastenings such as spikes or rudder nails. The main variation between a 'rag bolt' and 'ragged spike' is the former has a circular shaft while the latter is square (2). These large circular sectioned nails, sometimes called short, or blind, bolts do not project through the timbers that they joining, by being 'ragged' it secured a greater holding power (3).
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Detail of the Royal Navy broad arrow mark
(1) Falconer, W (1780) Falconer's Marine Dictionary, Salzwasser-Verlag Gmbh,
(2) McCarthy, M. (1996), Ships fastenings: a preliminary study revisited. International Journal of Nautical Archaeology, 25: 177–206
(3) McCarthy, M. (2005) Ships' Fastenings: From Sewn Boat to Steamship. Texas; A&M University Press