1989:007 - BUNRATTY EAST, Clare

An excavation was carried out at Bunratty Castle and Folk Park from 26 June 1989 to 14 July 1989. The work was carried out in advance of development to an "Underground Passage" which the writer interprets as a limestone and brick bridge. It is situated to the north of the north-east tower of Bunratty Castle, east of the moat and west of the Raite River. The bridge is aligned in a north-west-southeast direction with the roadway passing over it at an unusual north-north-east angle.

Recent surveys of the site describe it as an "Underground Passage" however, on close examination, the site appears to consist of the well-preserved remains of a limestone and brick bridge. The sand and silt floor under the eye of the bridge was the area excavated. For convenience, the base of the bridge will be called "the passage" in this report. Interior dimensions: 18m long; 1.86m high; 4.1m wide.

The passage is vaulted and consists of roughly coursed limestone rubble. The vaulting is low and wide and is segmental in form. The vaulted area above the arch springing is roofed in red brick for the entire length of the passage. The underside of this vault is rendered with lime mortar, thus obscuring much of the brickwork. At either end of the arch the bonded headers and stretchers are clearly visible. There is slight sagging of the roof of the arch towards the centre of the passage. A 4.18m extension to the bridge appears to have been added. It is identical in every respect to the rest of the passage. There are no signs of keying-in of stones. A number of subrectangular putlog holes are also visible within the passage.

The moat which surrounds much of the castle stops just short of this bridge and would have originally met the mouth of the original passage/bridge at a 120 degree angle. The original bridge was 4.18m shorter than its present length. It is possible that the bridge is related to the moat and that it originally acted as a drainage channel for it. Many repairs have been made to the passage in recent years including some repointing of stonework, the laying down of a concrete threshold and the hanging of double doors at the north opening. Pipes were also laid along the interior of the north wall of the passage below ground level.

Excavation
Large quantities of modem debris were first removed from the south entrance. The level in the passage was then reduced by an average of 0.7m throughout. The soil underneath the gas and electrical piping in the passage was not disturbed as this had been disturbed in the relatively recent past by the laying down of the same pipes.

During the summer period the summer water level averaged at about 0.7m below ground level. This water level usually rises by over 1.12m during the winter months.The remaining 0.3m consisted of silty clay and also modern debris. A further 1m sq. area was also excavated to a depth of 0.3m through the waterlogged silt. Some modern deposits were also uncovered from this level. The only find was that of an oval-shaped water-rolled stone at base. Probing would suggest that the foundation for the bridge was at about this level and that a silty clay base comprised the foundation with some gravelly material also included. There was no evidence of a plinth.

In summary, no stratified material was uncovered to give an indication as to the precise dating of the bridge. However, its position in relation to the moat is of interest as the moat is thought to be at least of mid 19th-century date. The bridge's red bricked vaulting is also important. Vaulting in red brick was a very strong feature of the "Great Earl's Restorations" and possibly indicates a late 16th- or early 17th-century date for the structure.

The excavation took place with the assistance of the Shannon Heritage Co. and also FÁS Shannon. (The excavation will be published in full in the 1991 issue of The Other Clare.)

Market Street, Clifden, Co. Galway