This Road, Class 1 consists of a substantial togher orientated west-northwest–east-southeast that ran across Mayne Bog from the River Inny on the west to an area of higher ground to the east with a recorded length of 657m. The site continues further to the east into the high bog towards the dryland where potentially an additional 150m may be preserved at a depth of over 1m. The trackway was investigated in a single cutting in 2006 under licence number 06E0928 and 44 sightings of the trackway in drainage ditches were also recorded across the production bog. The excavation exposed a structure composed of tightly packed transversely-laid oak planks, most of which had been mortised and fixed in place with roundwood pegs. The planks measured up to 4.40 in length, 0.30m in width and 0.06m in thickness. The substructure consisted of light brushwoods, plank fragments and wood chips which were scattered across the surface of the bog. Some of these elements had been arranged into three roughly longitudinal lines of brushwoods. Two dendrochronological samples were dated to 882 BC ± 9 years or later (Q11708) and 879 BC ±9 years or later (Q11707) while a radiocarbon sample from the superstructure returned a calibrated date of 1200–820BC, dating it to the later Bronze Age.
Following a site inspection in December 2014 by IAC Ltd at the request of Westland Horticulture Ltd, the plank track (WM002-038 / MYE001a-as) was identified at 32 sightings. At the eastern extent of the production bog, in the first drain the sighting (MYE001as) was 1.10m beneath the surface of the high bog. In the next four fields, peat cover was 0.20–0.30m. By the fifth field it was on the field surface. Its condition varied from field to field but was in general truncated and removed at the drain edges with the surviving elements visible towards the centre of the production fields.
The 2015 excavations were carried out under licence 15E0057 at sightings MYE001b (Cutting 1), MYE001af, (Cutting 2) and MYE001ao (Cutting 3). Excavation revealed that this substantial Late Bronze Age plank trackway was constructed of closely placed, transversely laid, radially split oak planks creating an upper surface that ranged from 2.40–6.13m in width with an average width of 4.70m. They were secured in place with roundwood and split oak pegs and supported by a substructure of mainly longitudinal, sparsely laid, brushwood elements consisting of alder, ash, birch, hazel, willow, oak and pomaceous fruitwood (pomoideae). While the basic construction remained the same across the three cuttings excavated in 2015, and in the previous 2006 excavation, variations were evident across all cuttings mainly due to underlying ground conditions. Cutting 1 and 3 showed evidence for slippage/slumping of the site because of large pools that it was constructed across and the amount of substructure and pegs varied across all three cuttings. The majority of the planks contained at least one, if not several, mortice holes with comparatively few containing in situ pegs. It is possible that the mortices were pre-prepared on the dryland and were used as required once put in place in the site. The mortice holes may have been used to facilitate transportation of the planks out onto the bog surface. The site was traced for a length of 657m within the production bog but it continues further to the east into the high bog towards the dryland where probing confirmed that it continued for an additional c150m at a depth of over 1m.
Palaeoenviromental analysis confirmed that the raised bog was well-established when the trackway was constructed and the surrounding peat was a fluctuating wet and dry location. Pollen analysis showed that the peat was wet during the time of trackway construction due to the heightened presence of Typha (bull rushes) and increase in testates such as Amphitren Flavum and Amphitrema wrightianum, indicators of wet ground conditions. The dominant insect species identified were aquatics like Hydroporus spp., Cottongrass and sedge feeders like Plateumaris discolour/sericea and generalist wetland species like Cyphon spp. Insects such as Micrelus ericae which are indicative of heather or Calluna which might point to heather growth on the surface of the trackway.
Similarly dated, transversely laid, plank trackways have also been recorded and excavated in Derryoghil Bog, County Longford, Longfordpass Bog, County Tipperary, Annaghcorrib, County Galway with two in Clonad Bog, County Offaly. While the sites all vary somewhat in composition the site which most closely parallels that at Mayne was the site of Derryoghil 1, excavated in County Longford by Raftery (1996). The Derryoghil site, which was dated to 938±9BC, also consisted of split oak planks transversely laid, with mortices and pegs, supported by a substructure of longitudinal elements. In the case of Derryoghil 1 the substructure was composed of large longitudinal roundwoods and plank fragments, and was thus a more substantial and defined structure than that which underlay the Mayne trackway.
