Metalworking site

The National Monuments Service's description

Eighteen potential archaeological sites were found during monitoring of topsoil-stripping on the Celbridge Interchange, from April to December 2001 (Licence no. 01E0306: www.excavations.ie). Most were resolved through subsequent excavation. The scheme was approximately 4km in length and ran from Celbridge to Leixlip through gently undulating land with a mixture of arable, pasture and woodland. The southern part of the scheme runs through an area heavily influenced by 18th-century landscape design, with avenues, woodland and tree-lined field boundaries centred on the early 18th-century house at Castletown.
This site (Site 5) was excavated under the monitoring licence. It measured approximately 8m by 11m. Three bowl furnaces and two associated burnt deposits were found. The area was truncated by one of the boundary ditches dividing the deerpark of Castletown and separating Castletown townland from Kilmacredock Upper.
Furnace 1 consisted of twelve contexts. It was 0.44m north of the townland boundary that truncated the site. The bowl of the furnace cut through the natural subsoil. It was flat-bottomed and circular with almost vertical sides, 0.47m wide on the surface and 0.39m at its base. It was 0.25m deep. The fills were rich in charcoal and slag. There was evidence that the bowl may have been recut. A 20mm-wide stream of metal was found to have flowed from the base of the furnace on the south-western side for 0.42m.
Furnaces 2 and 3 were 9.5m to the south-west of Furnace 1. Furnace 2 joined Furnace 3 on its north-western side; both cut the natural subsoil. Eight contexts were associated with Furnace 2. The bowl was 0.39m in diameter with almost vertical sides and a concave base. Its fills were also rich in charcoal and slag. A possible plume was found in the third fill of the furnace.
Nine contexts were associated with Furnace 3. The bowl was 0.4m in diameter on the surface and 0.32m at its base. It was 0.22-0.26m in depth. Its fills were rich in charcoal and slag. The third fill out of four was made up of packed burnt clay which might have been part of the furnace's superstructure.
Three features were associated with the furnaces: a stake-hole, an area of burnt material and a shallow cut with burnt material, C37.
No completed artefacts or metalworking tools were found on site. More research will have to be carried out to determine whether the furnaces were for smithing or smelting. It might be suggested that they were for smelting since there was a possible plume in Furnace 2 and no crucibles or moulds were found. The pit C37 may have been used for roasting ore prior to smelting. Since there were three furnaces, both smithing and smelting may have been carried out on site.

Compiled by: Gearóid Conroy

Date of upload: 10 June 2011