2004:0565 - DUBLIN: Building C, Spencer Dock, North Wall Quay, Dublin

Monitoring and excavation were carried out on the site of Building C, Spencer Dock, North Wall Quay, Dublin 1, between January and September of 2004. Three principal phases of activity were uncovered. Monitoring on the site of a northern block (RSTUV) is ongoing. To date, 19th-century foundation remains have been uncovered. The results of monitoring on this block will be reported in Excavations 2005.

Late Mesolithic
The earliest phase relates to fishing and other activity carried out when the Liffey estuary occupied the south of the site. The transition of silt and gravels uncovered between 13–16m north of the southern limit of excavation marked the old shoreline of the Liffey channel. The remains of wooden fish traps, stake rows and miscellaneous pieces of worked wood were preserved in the waterlogged silts. A semicircular wicker structure or fish trap comprised stakes and a series of smaller upright rods, around which rushes had been woven. A radiocarbon date of 6090–5840 cal. BC was returned for this feature. Along the shoreline to the south-west of the fish trap was a deposit of horizontally set roundwoods. These were truncated to the east by machine excavation, but the remains covered an area 3.4m by 1.28m and have been radiocarbon dated to 6070–5890 cal. BC. In the south of the site was a row of 36 stakes aligned northeast/south-west; a date of 5920–5720 cal BC was obtained for one of these stakes. Along the western shoreline, to the north of the western stakes, were the remains of a wicker-basket-type structure and a group of stakes. The structure, which survived up to 0.6m long and 0.3m wide, has been dated to 5990–5750 cal. BC. On the west of the site were two rows of rods and stakes, a horizontal panel of wicker (dated to 6100–5970 cal. BC) and a fragmentary wicker fence, which were probably part of a truncated fish trap.

The fish traps were constructed mainly but not exclusively of hazel and were in a good state of preservation. In addition, there were several other stakes and pieces of worked wood, which did not form any coherent structures.

Phase 2 was the reclamation of land from the estuary and its floodwaters. This was achieved by depositing a series of fills in order to build up the ground. Artefacts recovered from these reclamation deposits have been dated to the 18th and 19th centuries and corroborate with the documentary sources in indicating the date when this work was carried out.

The third phase was the development of the reclaimed land. From the later 18th up to the 20th century a series of structural remains were founded on the reclamation deposits and the site was drained by a series of brick culverts cut into these deposits. In the south of the site, c. 112m to the east of the canal and 45m north of where the canal opens into the Liffey, were the remains of a circular masonry structure. This had an internal diameter of 11.2m and its encircling wall was constructed of limestone blocks (0.35m by 0.22m by 0.16m), bonded with mortar. The wall was 1m wide and survived to a maximum of 1m in height. In the west was an entrance. Leading from the western entrance was a walkway, which comprised two rows of granite slabs on either side of which was a red-brick floor (6.1m by 5.1m) and to the west were four sandstone slabs. To the east of the floor and abutting the external wall was a north-south masonry wall with an eastern return at its north. This was probably an internal division within the circular structure. This was the earliest masonry structure uncovered on site. Its location roughly corresponds with the windmill at North Wall Quay, which was recorded as being 100m east of the mouth of the Royal Canal. The windmill had burned down in a spectacular fire late in 1810 but is shown on Taylor's map of 1816. The inclusion of the windmill on Taylor's map suggests that it was reconstructed after the fire of 1810. However, it is not shown on the first-edition OS map (1837), which shows a warehouse on the same location. The western wall of this warehouse was uncovered during site works, partly overlying, and therefore post-dating, the windmill wall. The archaeological evidence corroborates the cartographic evidence in indicating an early 19th-century date for the windmill. It was larger in diameter (11.2m) than typical tower mills (4–6m). Its location on low-lying ground, which was prone to flooding, suggests that it may have served for pumping and draining water rather than milling corn.

To the north, west and south of the windmill structure were a series of 19th- and 20th-century walls and basement floors, which largely corresponded with the structures shown on the OS maps. A series of five arched vaults was uncovered along the street front and extending under the road, south of Nos 46 and 47 North Wall Quay. The vaults extended for c. 16m east-west and were accessed from the north through an arched corridor. The individual vaults measured c. 3m long and 3.2m wide and the corridor was c. 1.5m wide. The vaults were constructed of limestone blocks bonded with mortar.

Red and yellow brick used in the upper structure of the walls may represent modifications to the original structure. These vaults were filled in and remain in situ.

27 Merrion Square, Dublin 2