2007:636 - BOFIN HARBOUR, Inishbofin, Galway

Introduction
Continued monitoring of dredging works in Bofin Harbour on Inishbofin, off the Co. Galway coast, led to the discovery and subsequent excavation of a previously unknown wooden shipwreck and two iron cannons in the inner ‘Pool’ area of the harbour. Following the discovery, an archaeological survey was undertaken to assess the nature and limits of the wreck and to further assess the potential impacts of the dredging on its preservation. The results of the survey clearly demonstrated that, given the extent of the reduced sediment in the area and the continued requirement for further dredging, the shipwreck could not be preserved in situ and consequently an upgrade of the monitoring licence to excavate the vessel was issued.

The shipwreck was excavated over several low tide opportunities between September and November 2007.

Shipwreck and cannon recovery site
Reduced sediment consequent to dredging works exposed the vessel in the inner ‘Pool’ area at NGR 54038 64846. At low tide the wreck was partially exposed in the intertidal zone. The calm protected inner area of the harbour has been used historically by the islanders and other mariners to repair, careen and maintain vessels and was/is further utilised as a graveyard for boats that are past their working life.

The two iron cannon were recovered during monitoring of land-based backhoe track machines beside the ‘Old Pier’ of the inner harbour area.

Description of shipwreck excavation
A bund of material had been partially placed around the wreck to maximise the length of the working tidal opportunity in such a dynamic environment. The excavation team followed the receding tide and commenced removal of the overburden sediment from the vessel with hoes and shovels while a track machine rebuilt the bund and emptied the site of water around it. This methodology was repeated every day of the excavation.

Between 1700kg and 2400kg of heavily compacted secondary ballast was removed from the wreck over the course of the excavation. The ballast comprised dense industrial slag tightly packed into the bilge area of the vessel.

As the overburden of sand, sediment and ballast was removed, the exposed timbers were cleaned, planned, photographed and recorded.

The fully revealed wreck comprised virtually the entire starboard hull section with its keel fully attached. The small vessel, 15.5m long, is a double-framed construction of oak futtocks and compass floors laid frame first. The elm keel extends as a single timber for 14.4m with a moulded dimension of 310mm and sided of 160mm and was through-fastened with iron bolts. Otherwise the vessel was entirely expensively fastened with oak treenails and nonferrous square-shanked nails and copper drift bolts.

Twenty runs of Scots pine strakes were recorded, with possibly only the sheer strake missing, while only a handful of the ceiling planks survived. Also surviving was the stempost, keelson, maststep and deadwood, all of oak. The vessel was payed over, within and without, with pitch. One notable construction feature was the insertion of a primary trimming ballast of dense mortar carefully set between each frame, which had been inserted when the ceiling planks were laid.

Artefacts from the wreck were few and included some barrel and bucket staves and a few barrel lids. A small fragment of hemp sailcloth was also recovered.

Post-excavation
Dendrochronology samples submitted to Dr David Brown of the palaeoecological department of Queen’s University returned negative results. The samples had no correlations with a suite of databases from Ireland, the UK, Europe or indeed the east coast of the United States. Consequently, it is possible that the oak may have been sourced in southern Europe or some other area of the US.

Line drawings created from the individual frame drawings demonstrate that the vessel had a steep angle of deadrise and low freeboard. The primary and secondary ballast also meant that the vessel would have sat low in the water and would have carried quite an amount of sail.

At present, it would appear that the vessel may be a fast revenue or smuggler’s cutter or privateer. That it was an ocean-going vessel is also manifest by the pervasive presence of the sea-boring mollusc teredo navalis throughout. This type of vessel had a general dating currency throughout the 18th and early decades of the 19th century.

The two iron cannon were located near the Old Pier c. 114m from the wreck. Initial research indicates that they date to around 1766 and are possibly French. The cannon are currently being conserved.

Ballycurreen Industrial Estate, Kinsale Road, Cork