County: Dublin Site name: DUBLIN: Bridge St Upper
Sites and Monuments Record No.: N/A Licence number: —
Author: Alan Hayden
Site type: Town defences
Period/Dating: Multi-period
ITM: E 714326m, N 734026m
Latitude, Longitude (decimal degrees): 53.344096, -6.283064
Test trenching
The site occupies an area on the west side of Bridge St Upr., bounded on the south by Cook St and on the west by Augustine St.
Limited test trenching and observation of boreholes on the site had been undertaken by Mark Clinton in 1982.
Five further trenches were opened by mechanical excavator on 4 June 1992. These confirmed that due to the great depth of cellarage on the Bridge St frontage the medieval town wall did not survive on the site. The ditch outside the wall however, ran down the site and was noted in a number of the test trenches. The site was subsequently excavated by the writer.
Excavation
A single trench 5m in width was excavated across the full width of the site over a three and a half week period from 28th September to 21st October 1992.
A small ditch survived over less than 5m of its original length due to the depth of later cellars. No finds were recovered during its excavation but the fact it was cut by the later town ditch and its similarity to ditches uncovered at Cornmarket (see no. 55, 1992) suggests a 12th-century date.
The 13th-century town ditch was excavated to a maximum depth of 10.5m below ground level where excavation was halted due to the quantity of water entering the trench. The original base of the ditch, judging from the slope of the sides, lay a further 2m lower. A maximum width of 17.5m of the ditch was excavated, its full width is likely to have been 20m across.
The ditch contained a very well stratified series of deposits dating from the late 14th to early 18th century and a huge quantity of finds of all types and dates was recovered.
The ditch appears to have acted as a watercourse as superimposed river beds appeared throughout its fills and a still flowing culverted stream occurred in its 18th-century levels.
The huge depth of the ditch appears to have been an attempt to allow the River Liffey to flow into it as far south as possible. Ground level slopes steeply upwards to the south and cores taken to the north of the excavated area show that the ditch suddenly becomes much shallower there. This is probably a result of abandoning the idea of allowing inundation of the ditch by the Liffey due to the difficulty of excavation to an increasingly greater depth.
Work was commissioned and funded by the developers.
15 St Brigid's Rd Upper, Drumcondra, Dublin 9
