ADCO was appointed to monitor the dredging activity associated with the landfall for the GAS 2025 Irish Sea Interconnector pipeline as it approached the east coast at Gormanston, Co. Meath.
It was necessary to cut a pipe trench 40m wide and up to 5m deep below existing seabed level, over a distance of 4km from sea to shore. Preparatory assessment did not indicate any archaeological material along the proposed pipeline route, but the records of more than 40 boat- and shipwreck sites in the vicinity dating from the 1600s suggested that this was an area of high potential.
A programme of 24-hour monitoring was carried out during the works project over two months at the request of the state authority, to record the type of seabed material that was being excavated. The dredging was undertaken by the Irish Dredging Company Ltd. using two separate platforms: a working barge, the Manu Pekka, was used for inshore work, while a trailer suction hopper dredger, Medway II, completed the dredging out to sea.
ADCO personnel maintained a record of position and dredging area, and observed the actual dredging, noting dredge depth, progress of dredging, and any items of interest.
Recovery of the logboat using lift bags
At 20:30 hrs on 02 June, seven timbers were retrieved by the backhoe dredger. The timbers were all retrieved from the same location. It was apparent that further remains lay within the seabed. The discovery had occurred while dredging was removing the upper two metres of seabed. A ridge of undredged material remained across the c. 50m-wide trench in this location. A dive operation was undertaken to inspect the location.
The wrecksite was loccated at 53° 38.917’N 06° 12.41086’W, or NGC 318622E 268012N. It was evident that a large piece of wreckage remained on the seabed. A second dive operation was carried out to clear the 2m of overburden at the undredged portion, and to remove the timbers from the seabed. It was estimated that this work would take nine days to complete. In the event, the work was completed ahead of schedule on 22 June, after six days of site work.
The excavation opened a cutting c. 6m x 5m over the buried portion, and removed the sand with suction dredges. The wreckage was identified, planned, recorded, and lifted from the seabed, and dredging proceeded without interruption to the overall schedule.
The archaeological data recovered represents an important discovery. It constitutes a logboat, or dug-out canoe, that measured 7m in length and is the first such discovery in Ireland from an active marine environment. This boat represents the clear evidence for the first time that early man plied the coastal waters in such fragile craft, which presumably were used to ferry people and supplies along the coast.
The logboat was conserved at the Mary Rose Trust in Portsmouth, England, and has been returned to Ireland. The National Museum of Ireland arranged for the vessel to be loaned to the County Louth Museum in Dundalk, where it is to feature as part of its collections.
A C14-determination of a sample of the timber was analysed at the Chroon Lab in Queen’s University Belfast, and returned date of 1132-1013 cal BC, 2 sigma.
ADCO wishes to acknowledge the assistance of Irish Dredging Ltd, Allseas, Bord Gais Eireann, and JP Kenny Ltd consulting engineers for this scheme
