2009:AD5 - EAST WALL TO INCHICORE WORKS, DUBLIN, Dublin

Monitoring of the extensive geotechnical site investigation drilling works for the DART underground between East Wall and Inchicore Works encompassed the monitoring and direction of archaeological site investigations for over 160 separate rotary, cable percussive and window sampling boreholes across the centre of historic Dublin. The extent of involvement in the investigations was ranked commensurate with the archaeological importance of each borehole location, as determined by the existing archaeological data for Dublin and through consultation with statutory authorities. The result has yielded a unique coarse-grained background of archaeological data indicating the depth of archaeological deposits, albeit not always details about either their nature or date, across Dublin. More precise data was also gathered for certain locations of high archaeological significance. For brevity, very summary conclusions here are grouped into nine sections.
Inchicore Works to Heuston Station
With two exceptions, the boreholes in this section were located close to railway buildings, sidings and tracks and were all affected by works related to the building and maintenance of the railway. The area along John’s Road had been reduced, leaving no surviving evidence of earlier activity. Near Memorial Park, two boreholes were located within the ground of a Gaeilscoil and what was once a quarry and landfill site. The landfill was up to 2m in depth, with bands of refuse material, including a dump of industrial filtration material from the 19th or early 20th century.

Victoria Quay and Guinness Brewery
The boreholes within the old Guinness Brewery were all located close to Victoria Quay and within lands reclaimed in the early 19th century when the river was straightened and new quays erected. The upper 0.9–1.5m below the existing surface contained a number of brick walls and surfaces that were in use from that period up until their destruction when the modern layout of the brewery was established. Below that level there was 2–4m of mixed rubble and sedimentary silts; organic waste with bone and shell was present in the boreholes furthest to the east and south, suggesting that these areas were closest to the old shoreline illustrated on the Roque map of Dublin (1756).
Usher’s Island
The soil profiles from the boreholes in this area were all similar, showing post-medieval fill up to 1.7m depths over c. 4m of mixed tidal/river sediment and fill/dump deposits. This area was reclaimed from the Liffey in the early post-medieval era, with some historical sources suggesting that the river margins were coming under development from medieval times.
Cook Street
The boreholes here confirm that the area has a deep archaeological sequence of reclamation deposits extending down to 4.7–4.85m below the existing ground surface (0.16–0.01m OD). Post-medieval structural remains, pre-dating the widening of the street, were identified immediately beneath the north footpath.
Wood Quay/Christchurch
Window-sampling boreholes were used, under archaeological direction, in the Wood Quay (Civic Offices amphitheatre) area, to facilitate understanding of deposits there. The results confirm the record of previous excavations on the site, including the presence of unexcavated baulks of intact archaeological deposits. A rotary borehole to the south-east of the Civic Offices was located c. 5m to the west of a previous excavation by Linzi Simpson (Excavations 2008, No. 405, 08E042) on the site of the medieval church of St John. A calp limestone wall 0.65m below ground surface (11.11m OD), and a quantity of disarticulated human bone, were uncovered. The wall is likely to be part of an 18th-or 19th-century renovation of the church building. The bone was analysed and then returned for reburial in the inspection pit adjacent to the borehole. Like the substantial amounts of redeposited human bone retrieved during the aforementioned excavation, the disarticulated remains are likely to have derived from the graveyard attached to St John’s, disturbed and redeposited during an 18th-or 19th-century rebuilding programme.
Dublin Castle and Castle Street
A borehole in the Upper Yard contained 4.4m of predominantly post-medieval fill over natural boulder clay. Three boreholes were located in the area of the ^Dubh Linn’ associated with the Viking and Hiberno-Norse settlement. Much of the identified bulk infill material contained post-medieval artefacts, but medieval material was also present. The area of the castle gardens and the present Lower Yard were laid out and extensively renovated in the 1560–70s, and some of the infill probably related to this period as well as later rebuilding programmes.
Castle Street showed strong evidence for the preservation of medieval structures and soils beginning c. 4m underground. Oak timbers encountered at 3.9m and 4.4m below present ground level (10.1m OD and c. 10.2m OD, respectively) suggest the survival of wooden structures. Stratified layers of medieval deposits and structures are known to be present at Castle Street, and the results of excavations in the area have demonstrated that large wood-framed high-status dwellings occupied the high ground overlooking the city quays from the 10th century and well into the Anglo-Norman period. A layer of wattle and fragmented timber-rich soil from 4.3–4.6m (9.7–9.4m OD) in one borehole here probably represents the early occupation layer from the Viking settlement.
St Stephen’s Green
Soil profiles here demonstrated varying depths of between 0.75m and 2.5m over natural subsoil, indicative of landscaping there and the probable former location of the north perimeter ditch for the post-medieval green. Because of the history of the area, particular care was taken with the inspection and metal detection of extracted spoil here, but no archaeological finds were recovered.
St Stephen’s Green to Sir John Rogerson’s Quay
Two boreholes in this area were drilled directly behind the existing quay wall on Sir John Rogerson’s Quay. The substantial standing remains of the old wooden quay wall were encountered at 4.1–7.6m (–1.13m to –4.63m OD).
North Quays to East Wall
There was no certain evidence of archaeological deposits in this area. The area has been heavily truncated, levelled and filled with post-medieval and modern landfill deposits. Immediately behind the North Quay wall, boring demonstrated slightly over 7m of fill (base –3.87m OD), but no evidence of prehistoric foreshore archaeology akin to that identified nearby by Melanie McQuade at depths of
c. –6m to –4m OD (Excavations 2003, No. 565, 03E654, and Excavations 2007, No. 494, 06E0668).