2001:826 - LOUGH BANNOW III BOG, Derryglogher and Derraghan More, Longford

These excavations were carried out as part of the 2001 Bord na Móna (BnM) Mitigation Project. This area of bog has undergone previous surveys, excavations and reassessments by the Irish Archaeological Wetland Unit in 1991 and by ADS Ltd in 1999. These sites were recorded in 1999 as brushwood and roundwood toghers, hurdles and worked wood in situ. At this point they were already substantially milled out, so by the time mitigation began it was difficult to distinguish several sites from each other. Four separate sites were excavated.

One definite togher was excavated which was, for the most part, in a good state of preservation. It consisted primarily of longitudinal roundwoods, with some brushwood and twigs infilled between the roundwoods. It was very compact and was three to four layers deep in places. It was traced along the BnM field surface for c. 60m in a north-east/south-west direction. The remaining sites, which were in a poor state of preservation, appeared to radiate out in different directions from this substantially constructed togher.

Two cuttings that measured 3m by 5m were placed over the roundwood and brushwood togher (99DR0001a). A 2m by 2m cutting was placed over 99DR0005a. A cutting measuring 2m by 2m incorporated the excavation of site 99DR0007 and 8a.

The first cutting was located beside a drain as the site (99DR0001a), which had been cut obliquely by the drain, could be seen protruding from the drain face. The site was located in well-humified Sphagnum spp peat with inclusions of reeds (Phragmites spp) and white sedge-type material. The upper surface of this site was constructed of c. 30 relatively large roundwood timbers and some brushwood placed longitudinally along the line of the togher in a north-east/south-west direction. The roundwoods were compacted together and formed the main body/walking surface of the togher. At the western edge of the togher there were concentrations of brushwood, twigs and some tree roots. The brushwoods averaged 0.03m in diameter and were slightly disturbed by milling. The substructural elements of this togher were very similar to the upper surface layer. They were composed of roundwoods and brushwood between which was a compact collection of smaller brushwood. It appears that this site may have been constructed using layers of similar wood and that is why there was no definite super- or substructure noted. The track, as revealed in this cutting, measured 3m in maximum width and 0.15m in maximum depth. It consisted of layers of brushwood and roundwood compacted together to form a stable walking surface across the bog.

The second cutting was located approximately 1m south-west of the first and revealed a continuation of the same togher. This sighting was also exposed in that it had been cut by a BnM drain. It was composed of over 60 brushwood and 10–20 larger roundwood elements, exposed on the field surface. The orientation of these elements appeared to be mainly longitudinal, running in a north-east/south-west direction, along the line of the site. There was some milling damage on the upper surfaces of the roundwood but bark was present on nearly all the wood pieces. Milling had also disturbed the arrangement of the brushwood and roundwood. The site measured 3.5m in width and was over 0.3m deep in this cutting. No pegs or transverse supports were recorded in either of the cuttings.

The third cutting was placed along the western side of Cutting 2 as it was noted that a site (DR0005a) radiated out from this cutting towards the western edge of this bog. The brushwood associated with this site was exposed on the field surface prior to excavation and as a result the wood was broken up and had been extensively damaged. The peat surrounding the wood was dark brown in colour and was well humified. It contained a lot of grassy sedge material with inclusions of reed materials and tree roots. This brushwood site measured 2m in maximum width and was traced for a length of 3m. The site was badly disturbed on the western side of the cutting in comparison to the eastern half, where there was some structure evident. The site appeared to be composed of c. six roundwoods, 0.06–0.15m in diameter, and numerous pieces of brushwood as well as several outlying fragments. The diameter of the brushwood ranged from 0.02m to 0.05m. Fifty per cent of the elements ran transversely and 50% were placed longitudinally. The wood was not very compact, which may have been due to heavy damage from milling. Roots were dispersed throughout the cutting. Wood was scattered around this site and exposed all over the field surface. After the field surface was shovel-scraped it appeared that the site exposed in the cutting continued in a south-eastern and southern direction. It appears to have been a junction of tracks from various directions leading towards the substantial roundwood and brushwood togher exposed in Cuttings 1 and 2.

The fourth cutting (99DR0007 and 8A) excavated was 10m to the west of Cutting 3 on the next BnM field surface. The site, which was similar in appearance, was composed of brushwood (60%), twigs (38%) and fragments of roundwoods (2%). The elements were densely restricted to the south-east corner of the cutting, spaced 0.04–0.25m apart. The brushwood varied in diameter from 0.01m to 0.03m and up to 0.5m in length. The twigs varied between 0.01m and 0.02m.

The majority of the elements were orientated in a north-west/south-east direction. The roundwoods were laid above the brushwood and twigs and were orientated east–west. The brushwood was laid at 0.06–0.12m intervals and the twigs were used as a packing between the brushwood to make the structure more stable. Seven twig pegs were noted. As at Cutting 17, numerous tree roots were spread throughout the cutting. This cutting was extended on the opposite (east) side of the drain. It measured 2.5m by 1m, and after excavation seven roundwoods and over 50 brushwoods were exposed. The site was covered in peat at this location and therefore the true composition of the structure was uncovered here. It consisted of roundwoods (30%) and brushwood (70%) and some twigs. The roundwoods, which were laid on top of the brushwood, measured 0.06–0.12m in diameter and up to 1.3m in length. The brushwood, which measured 0.02–0.05m in width, was located under and between the roundwoods. The site measured 2.2m in maximum width and was traced for a length of c. 4m.

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