ARCHAEOLOGISTS ARE puzzled as to the exact purpose of an ancient oak road unearthed on a Bord na Móna bog in Co Tipperary.

Operations manager and site director with Archaeological Development Services (ADS) Jane Whitaker believes the track, which runs parallel to a modern road, may have formed part of an ancient road network.

The road, discovered by ADS during a walking survey, is constructed from oak planks laid across oak beams and gravel. Mortise holes have been bored into the planks to facilitate wooden pegs. All of the materials were brought to the site from other locations.

Using dendrochronology, the archaeologists have dated wood from the road to 986 BC. The Bronze Age structure measures 300 metres long and four metres wide.

Construction of the road would have involved “a substantial amount of wood, organisation, tree-felling, hard labour and graft”, said Ms Whitaker. “The reason for that is unknown but most likely just to cross the bog – it’s a causeway.”

A number of other finds have been made at the site of the road on the Longford Pass Bog in Co Tipperary in the past, she revealed. “Historically there have been quite a few finds, mainly in the early days of Bord na Móna hand-cutting. There is actually quite a large number of Bronze Age finds, similar enough in date to this site which would have been daggers and swords.” Mystery still remains as to the exact purpose of the road. Although the track is large enough to take wheeled vehicles, archaeologists have found no evidence of hoof prints or wheel ruts. “Interestingly, in this particular site, we have, in two of the cuttings, an upright timber with a hole in it along the northern end of the site, purpose and function as yet unknown.”

Environmental archaeologist Dan Young is studying samples to get a picture of the environmental conditions when the track was in use. “One hypothesis we are testing is that trackways were built as a response to climate change. That is something that is still ongoing – we have got some evidence for it at some sites but not all sites,” he said. Bord na Móna project archaeologist Charles Mount expects more artefacts to be discovered at the Longford Pass site: “The interesting thing is as you look you begin to see pieces of timber that may have been pieces of wooden artefacts. There may be one or two oars, there could be wall footings, and, as the wood is taken up and recorded, there may be more objects.”

Head of environment for Bord na Móna Energy Enda McDonagh said over 200 sites have been excavated on Bord na Móna bogs since 1992.

He said all bogs under the control of Bord na Móna have been surveyed at least once by archaeologists. The organisation owns about 7 per cent of the bogs in Ireland.