2005:973 - COONAGH WEST, Limerick

This brick-firing site (2080m2) was part of a larger industrial brick-manufacturing landscape tucked into a bend on the north bank of the River Shannon. The land had been reclaimed by the construction of embankments along the River Shannon and its tributaries, before the first-edition OS map was surveyed. An irregular-shaped ‘brick yard’ is marked on the OS Fair Copy Plan (surveyed 1839). Site A005/2010 lay immediately south-east of this brick yard, suggesting that these brick clamps were either later or went out of use earlier than 1839. The second brick-firing site excavated on the scheme, A005/2018 (see No. 974 below), was, however, within the confines of this boundary. In the area between the two sites were large parallel depressions, or ‘brick-holes’, where clay had been extracted for brick making. A quay marked on the OS Fair Copy Plan lay adjacent to A005/2018 and may have been used to load the brick onto boats for transport to Limerick city upstream to the east. Barrington’s Pier (2.5km to the east) was built for boats to bring bricks from the Coonagh brickfields to the city in the later 18th century (OL 1976). A water channel along the southern boundary of the site followed the line of the old pre-1839 embankment westwards to the quay adjacent to A005/2018 and could have been used for the transportation of the bulky brick. The general topography of the area is flat pasture with reeds, intersected by deep ditches draining into the River Shannon. A thin layer of topsoil typically overlies fine dark-blue/grey alluvial clay that deepens toward the River Shannon.
Several areas of activity were found on site A005/2010, including a ‘brick-hole’ in the north-east, brick-firing areas or clamps in the central area and a possible storage area in the west. The area of the brick production measured 42m east–west by 26.5m and revealed evidence of multiple brick clamps. Brick clamps were the simplest firing technique, where ‘green bricks’ (unfired bricks) were fired without permanent structures. On this site evidence for the clamps came from colour variations on the ground where reduced and oxidised areas indicated where the clamps had been sited. Reduced areas were black and oxidised areas red or orange. During firing, if sufficient oxygen is present oxidising conditions occur and allow carbon and sulphur in the clay to oxidise and diffuse as gas. If not enough oxygen is present, reducing conditions exist, which causes black cores in bricks. In some places the orientation of the individual bricks could be discerned. In the area of best preservation it seems that bricks were placed at right angles to the fire channels in at least ten double rows. There must have been gaps between the bricks to stop sticking and to allow the hot air to circulate. More bricks were stacked on top and tilted inwards to prevent collapse, therefore the clamp would have been wider at the bottom than the top. Fuel was packed in the channels between the rows. The channels also acted as draft holes. When the stacking was complete, the outside was covered in ‘the same clay, whereof the bricks were made, the thickness of two hands-broads or thereabouts’ (Boate, in Pavía and Bolton 2000, 196).
It was not possible to estimate how many clamps were located on Site A005/2010, but it can be said that many repeated firings occurred over a large area. It was also not possible to determine which area was the earliest and if the activity spread out over time or if more than one clamp was simultaneously burned. The stratigraphy on site indicated that repeat firings had taken place on top of each other. It seems that all stages of production occurred on site from excavation of clay to firing. Moulding and drying must also have occurred, but no trace of this activity was found. The firing activity was extensive and it can be suggested that several brick settings in the western area of the site might be footings for storage of the brick, where brick was stacked in low towers with the bottom bricks sinking into the clay and becoming too damaged to sell. No evidence for a pier or loading area was found, but it is possible that this might also have been located in the western area of the site, with a change of activity across site from initial preparation in the north-east to final stacking and shipping in the west. The water channel immediately adjacent to the site might have acted as a canal to the quay to the west of site A005/2018.
Since post-excavation work is ongoing, further discussion is not possible at present.
References
Boate, G, 1652 Ireland’s Natural History. London.
O.L. 1976 Old Limerick. Limerick.
Pavia, S. and Bolton, J. 2000 Stone, Brick and Mortar: Historical Use, Decay and Conservation of Building Materials in Ireland. Bray.