County: Galway Site name: Rathwilladoon 5
Sites and Monuments Record No.: N/A Licence number: A044; E3657
Author: Ed Lyne, IAC Ltd, 120B Greenpark Road, Bray, Co. Wicklow.
Site type: Charcoal clamp
Period/Dating: —
ITM: E 541062m, N 693935m
Latitude, Longitude (decimal degrees): 52.992907, -8.877891
At Rathwilladoon 5 (commenced on 10 October 2007) an area of 10m by 10m was opened up to reveal an oval pit filled with a dense layer of charcoal and a layer of clay, and a small irregular pit which contained a small amount of metal slag. This site was identified during linear testing, at which time a number of similar if less well preserved sites were recorded. These sites, which appear to be charcoal clamps, were all found in peripheral land, adjacent to low-lying wetland areas. Their location was probably influenced by the presence of suitable timber for charcoal production in these locations. This poor-quality land may have been used for the deliberate coppicing of certain types of tree for the purpose of making charcoal.
At Rathwilladoon 5, the charcoal clamp consisted of an oval pit measuring 2.82m in length and 1.22m in width, with a depth of 0.14m. The clay along the sides of this cut was scorched red from burning in situ, and the basal fill, which was 0.09m in depth, consisted of pure charcoal pieces, some of which were quite large. The upper fill was a brown sandy silt with some charcoal. This may have been a deliberate deposit to fill up the pit after use.
Such pits were used to produce good-quality charcoal, which was required for metalworking. Charcoal generates higher temperatures and a cleaner environment for metalworking than timber.
The discovery at resolution stage of a small pit (0.19m by 0.15m and 0.13m deep) adjacent to the clamp, with charcoal and some metal slag fragments, suggests that in this case the charcoal was not being transported elsewhere, but instead was being used on site for the production of metal. An alternative explanation could be that a small amount of charcoal was tested to produce a small amount of metal on site, to ensure that the charcoal was of good quality. The reason for the abandoning of 0.09m of charcoal in the base of the clamp is unclear; perhaps it was not needed, or alternatively it may have become damp and lost its usefulness.
Prior to scientific dating it is unclear to what period this site dates, but an early medieval date is likely. The excavation was completed on 15 October 2007.
