2014:263 - Knockballyboy, Clonad Bog, Offaly

Clonad Bog was initially surveyed by the Irish Archaeological Wetland Unit (IAWU) during the course of the 2001 Archaeological Survey of Ireland, Peatland Survey. Seven of the sites identified were excavated in 2004 by Eoin Corcoran. A Re-Assessment survey was carried out on behalf of Bord na Móna in 2013 by the author under licence number 13E0229 and subsequently three sites were excavated in August 2014 by IAC Ltd during the 2014-2017 BnM Mitigation Project.
Two cuttings were excavated at OF-CND001, a transverse plank, north-north-west/south-south-east oriented, Road – Class 2 Togher at sightings OF-CND001a and OF-CND001b in the north-western extent of Clonad Bog.
Cutting 1 (OF-CND001b) measured 8m x 5m. Very little peat cover remained over the site at this location. It was a maximum of 0.02m deep and was moderately to well humified sphagnum-rich with frequent small calluna root inclusions. The site was composed of closely placed, transversely laid, split oak planks forming an upper surface 2.14–3.5m in width supported by longitudinal planks and delineated by split oak and roundwood pegs. The planks ranged in size from 0.08–0.2m in width, 0.02–0.08m in depth and 0.93-2.65m in length and were a mixture of half-split and radial-split oak timbers. Fine riverine sand had been used in places as a packing material between and over some of the planks. The relatively poor condition of the upper planks suggests that this site may have been exposed to the elements for some time prior to becoming inundated. The underlying peat was weakly decomposed, rich with occasional calluna and small root inclusions.
Cutting 2 (Of-CND001a) measured 3.5m by 4.5m and was located on a former stockpile field. The overlying peat was 0.9m deep with six distinct layers identified within it. The peat immediately overlying the upper surface of the togher was strongly decomposed sphagnum peat 0.09m deep with occasional small woody roots and twig inclusions. The upper surface of the togher measured 2.85–3.5m in width and was composed of transversely laid split oak planks with occasional gray gritty clay/sand noted in places. The planks were closely placed with some overlapping and ranged in size from 0.13–0.25m in width, 0.04–0.11m in depth and 1.84–2.99m in length. The planks were a mixture of half-split and radial-split oak timbers and two had partial mortice holes with in situ pegs. Between and immediately below the superstructual planks was a layer of pale gray, gritty clay/sand material up to 0.18m thick and a maximum of 2.7m in width which in turn immediately overlay the substructrual elements. The substructure was composed mainly of longitudinally laid roundwoods with short transversely laid lengths of broken split oak planks between them and delineated by split oak pegs. The underlying peat was well humified sphagnum peat with frequent tree root and woody detritus inclusions.
A radiocarbon date of 1376-1123BC was obtained from a brushwood sample taken during the survey.

IAC Ltd, Unit G1, Network Enterprise Park, Kilcoole, Co Wicklow