1999:742 - KILLAGHINTOBER BOG, Castlearmstrong, Offaly

This linear trackway was traced across the Bord na Móna field surface for a length of 225m. Three cuttings, 5m x 2.5m, were placed at both ends and in the centre of the site.

The wood from the northern cutting, which was exposed underneath the milled peat, consisted of two transverse roundwoods, three pegs and some wood chips. In general the wood associated with this cutting was in poor condition and had been milled on the upper surfaces. The oak wood chips exposed probably represent the superstructural plank, which would have rested on the transverses and would have functioned as the walkway. The roundwood found at the northern end of the cutting was orientated east-west and would have originally functioned as a transverse support to the upper plank. The second transverse, which was found c. 1.8m south of the northern transverse, was slightly displaced and had degraded. It was 70mm in maximum diameter and 1.86m long. This transverse would also have functioned as a support to the upper walkway planks. Two pegs found beside the northern transverse would have added support to the upper plank walkway.

The wood exposed in the central cutting was similar to that excavated in Cutting 1. The cutting contained elements of an upper plank walkway with associated transverses, displaced planks and pegs. Four displaced and milled planks, which probably belonged to the superstructural layer of the trackway, were revealed at the eastern and southern sides of the cutting. These planks were split from oak timbers. Also associated with this layer were four pegs. These pegs would have originally secured the superstructural planks into the peat to prevent the planks from moving. The substructure, which was revealed at the northern and southern ends of the cutting, consisted of three degraded transverse planks. These planks would have acted as substructural supports to the upper, longitudinal planks.

Some of the wood found in this cutting had been exposed on the field surface for some time, and milling had destroyed the upper layers of the trackway. After initial trowelling two roundwood timbers, four pegs and some wood chips were found at the north-eastern end of the cutting. One of the roundwoods represented the remains of a transverse timber that would have supported the upper walkway. The second roundwood ran longitudinally along the northern half of the cutting. This roundwood was worked with a metal tool at one end. It may have lain alongside the upper plank walkway, after which it sank into the peat.

The underlying peat associated with this cutting was yellow and brown and contained layers of Calluna (heather) and sedges.

Although the trackway was destroyed and milled along most of its length, the overall composition and constructional elements associated with this site can be fairly well understood from this excavation. The trackway was a fairly simple construction comprising a linear plank superstructure possibly laid end to end and then supported by plank and roundwood transverses. In places an occasional roundwood may have lain alongside the upper planks. These roundwoods would have provided extra support to the actual walkway. The substructural transverses supported the plank walkway and elevated it off the wet peat.

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