2012:219 - Guinness Brewery, St James’ Street, Dublin, Dublin

The methodology for the second phase of test excavations was agreed with the City Archaeologist and the National Monuments Service, DAHG. A series of trenches were excavated along areas of impact focusing on high density pile lines within the 113m (north–south) by 60m footprint of the Brew House. Ground reduction of 1.7–2.1m was required to reach formation level for the pile foundations within the southern footprint area, with little to no excavation needed at the northern end. The trenches were dug from formation level during the construction phase and features identified were recorded and excavated.  Excavation to a depth of 2.9m was required at the location of lift pits, tanks, and a silo within the southern and eastern footprint of the Brew House. The grain storage pit (25.5m x 4.5m) at the eastern side of the building required excavation to a depth of 4.5m (-0.27m OD).  Ground reduction works carried out within the Fermentation Extension and the Brew House were monitored and all structural remains were recorded prior to removal. Post-excavation analysis is on-going. Excavation for the Attenuation Tank on the northern end of the site will be carried out in 2013 and will be monitored.

Monitoring within the 60m by 60m footprint of the Fermentation Extension located on the south side of Cooke’s Lane revealed rubble fill overlying mixed silt and gravel. The ground within this area had been heavily disturbed during previous construction work and the only features identified were late 19^th-century brick basements along Cooke’s Lane.

Medieval Occupation

The earliest activity identified within the footprint of the Brew House was a medieval soil horizon that overlaid natural gravels on the southern end of the site. Two deposits extended over a maximum area of 33m east-west by 12m. These were probably from the back gardens of properties that fronted onto Cooke’s Lane. A truncated pit that measured 1.1m by 0.8m and 0.09m deep was also identified.  Finds recovered from these features included eroded sherds of pottery and a line impressed floor tile of late 12^th–14^th-century date. The medieval deposits were sealed by dark grey silt that contained 17^th- and 18^th-century ceramics. There was no evidence for medieval occupation on the central and northern part of the site, which at that time was probably part of a flood plain. The earliest activity identified across much of this area (c. 25m north-south by 50m) was a silt deposit mottled with burnt red clay (121) that contained brick wasters. The wasters await analysis but may date from as early as the 17^th century. The 0.1m-thick deposit (121) was sealed by mid-grey silt from which sherds of pottery and clay pipe were recovered.

Millrace and late 18^th-/early 19^th-century occupation

A former millrace extended eastwards from the river Camac across the footprint of the Brew House and provided a source of water for various industries over the centuries. These included the Vitriol Works shown on the First edition OS map to the west of the Brew House and the late 19^th-century tanneries on Cooke’s Lane. A test trench excavated across the millrace revealed fill comprising tanning waste, overlying a deep silt deposit containing post-medieval pottery. The base of the millrace could not be investigated due to Health and Safety constraints and water ingress at a depth of 2m.

Two linear ditches and a series of pits were identified in the test trenches excavated to the north of the millrace. These features were cut into the silt deposits (006) and (009) and pre-date the garden depicted here on the First edition OS map. The finds recovered indicate an 18^th/early 19^th-century date. The ditches [125], [132] and an unlined pit [118] were filled with cattle horn cores and skull fragments that were probably waste derived from the nearby tanneries on Watling Street. A north-west/south-east-orientated ditch [125] located on the centre of the site was probably a drainage channel that connected to the millrace c. 12m further south. This ditch was 0.6m wide and was traced for c. 7.3m but its depth could not be accurately measured due to water ingress.  An east-west orientated ditch [132] was located c. 26m further to the east. This ditch was cut by a modern basement but survived for a length of 3.6m. It was 1.7m wide by 0.3m deep and contained sherds of 18^th-century pottery. To the north was an organic deposit containing plant remains that were probably waste from the tanning process. This 0.1m-deep deposit overlaid a burnt clay and measured at least 3.35m by 2m.  Pit [118] was located on the western end of the site c. 4m north of the millrace and measured 1.8m by 1m by 0.4m.

Four other pits [130, 134, 123, and 128] containing rubble and domestic refuse were excavated on the northern end of the site, over 12m to the north of the millrace. These pits ranged from 1.5m by 0.5m to 1.8m by 1.4m and were 0.3–0.5m deep. Sherds of 18^th/19^th-century pottery were recovered from them and leather cut offs were found in one of the pits [134] located 1.5m to the north of ditch [132].

Several early 19^th-century structural features were identified on site, but the majority of structures from this period were removed by later construction. Two masonry wall foundations, a pillar and brick drains partially exposed at the western edge of the site were probably part of the Vitriol Works. The foundations were of abutting north-south and east-west orientated walls that measured 0.5-0.6m wide and an associated 0.5m-wide square pillar. Two drains and a brick culvert uncovered to the north of the masonry walls averaged 0.6m wide and 0.4m deep.

Two walls on the eastern end of the site were probably part of the eastern wall and an associated basement of the narrow north-south orientated structure that occupied the area from Cooke’s Lane to the millrace. These walls were constructed of roughly coursed masonry and brick bonded with mortar.

Late 19^th-century remains

A north-south masonry wall and associated pier partially exposed at the western edge of excavation were probably the south-eastern corner of the main block of the Chemical Works illustrated on the 1864 OS map. The eastern wall of the eastern works building was identified as a 0.4m-wide masonry structure.

The remains of stone and brick-built tanning pits were recorded on the south-western part of the site in the area north of Cooke’s Lane and south of the millrace. These pits relate to two phases of the tannery illustrated on the 1864 and 1875 OS maps. The pits had all been cleaned out after their final use and a layer of lime was deposited in them before they were back-filled with rubble.

The first phase of the tanyard was represented by two north-south aligned rows of sub-rectangular sunken pits on the south-western end of the site. These rows were set 4m apart and had a similar layout. The southern pit in each row was a single masonry structure, to the north of which were two pairs of brick-built pits. The individual pits averaged 2.2m by 1.5m and were originally 1.5m deep or more.

Located 12m to the south of these pits were the truncated remains of a masonry floor and a brick structure that measured 2.5m by 1.8m and 4m by 1.9m respectively. These remains were at a higher level than the tanning pits but they could have been used for related activity.

To the west of the pits were a series of brick drains that may have been used in the tanning process. These cut through earlier drains associated with the Vitriol Works.

The second phase of tanning was represented by a row of three larger pits, located 1m to the east of the Phase 1 pits, and two heavily truncated wood-lined pits. The two northern pits in the row were brick-built structures that measured 4.5m by 2.45m and had small chambers on their eastern sides. An outflow in the walls of these pits connected to a pipe that ran between two levels of brick floor. The southern pit was a smaller masonry structure measuring 2.6m by 1.85m. A brick drain located to the east of these pits was probably associated with them. Two wood-lined pits were located to the south and east of the row of pits. They measured 2m by 1.55m and 3.4m by 3.3m respectively.

Two truncated stretches of cobbling on the centre of the site were part of a yard that was broadly contemporary with the tannery.

Three masonry walls on the southern end of the site were the remains of a mid-late 19^th-century structure.

A series of substantial masonry walls that measured 0.54-0.9m wide were associated with the railway lines illustrated on the 1875 OS map. A masonry pier and the base of a brick arch on the western edge of the site were the remains of the railway bridge spanning the millrace.

Located on the eastern end of the site within a structure dating from c. 1876 were the truncated remains of a brick floor and some sort of flue. The floor measured 4.2m north-south by 2.55m. It was delimited to the west by a 0.7m-wide masonry wall and to the east by a smaller brick wall. The central flue was built on top of the floor and was 1.2m wide. Its concave surface was charcoal stained and underneath its truncated southern end was a semicircular feature that measured 1.2m in diameter.  Located 2m to the south was an east-west orientated wall that abutted masonry wall (158).

A circular brick well measuring 1.18m in diameter was located to the north-east of the brick features (164, 165). An iron pipe fed into the well and it had been backfilled with cinder. Located to its east was a manhole and to the south was a brick structure with a stone drain on either side. This structure measured 7m north-south by 1.4m and was covered with a black ashy deposit.

A 0.6m-wide masonry wall dating from the 1870s was located to the west of well (173) and measured at least 12m north-south.

The covered well shown on the 1889 and 1911 OS maps was identified to the south-east of well (173). This brick structure measured 2.52m in diameter and had a cast iron lining.

20^th-century structural remains

Basement remains uncovered on the south-western end of the site were from the early 20^th-century saw mill and a later structure depicted on the 1969 OS map.