2009:381 - ARDBEAR, Galway

A proposed sewerage scheme is earmarked for a section of the shores of Clifden Bay, and an initial assessment and intertidal survey recorded a substantial sea wall of uncertain date or function. Part of the proposed outlet pipe will cut through c. 3m of this wall and this section was cleaned up, drawn and excavated ahead of any work. The sea wall is solidly built and named ^Training Wall’ on an Admiralty Chart of 1847. The portion to be affected by the works is on a 27m-long stretch running roughly east–west and terminating at higher rock outcrop at either end. The excavated sector showed a batter on the north side which covered a distance of 0.5m over a drop of 0.55m and was three courses high.
Along the south side the wall construction did not appear as well preserved, however it still comprised undressed or roughly dressed schist two to three courses high. A batter of 0.5m distance over a height of 0.6m was seen here. The wall core comprised medium-sized (0.25m by 0.2m by 0.15m average) to larger medium-sized, to some larger blocks (0.9m by 0.44m by 0.28m), with the latter found mainly at or near the top. At the base of the wall, a layer of silt or mud may have formed a natural foundation for the wall blocks. Near the central base of the wall, a large block of mica schist was found partly embedded in the silt and this bore the remnants of two chisel-cut holes. This stone was one of twelve chisel-marked stones from the excavated sector of wall, and diameters of the drilled holes varied from 0.036m to 0.06m across. The very base of the wall was never water-free as even the lowest tide covered it slightly. The training wall was probably built by Nimmo in the 1820s and its function was to regulate and train the waters through the channel, keeping its course clean and being able to better facilitate craft at all times. Excavation of the trench for the outlet pipe will be across c. 250m of the bay at low tide and this will be monitored archaeologically whenever it is undertaken.