2024:619 - Seabed, Dublin Port, Berths 52-53, Dublin

A second Season of Capital Dredging was carried out as part of the Dublin Port Master Plan 2 (MP2), facilitating the installation of engineering fill (in advance of piling operations) and the construction of a propeller wash screen.

The dredging works were completed at Berth 52 (Preparatory Piling area) and Berth 53 (Dredge Pocket Extension) between 4 February 2024 and 27 March 2024.

The Preparatory Piling Area at Berth 52 is located on the west side of the Northern Widening Area (NWA). The area measures 53m north-south (max.) by 130m (max.). The Dredge Pocket Extension is situated 15.6m east of the pilling area and measures 25.8m (north-south) by 34m.

Dredging operations were carried out using a long-reach excavator, mounted on a spud-leg barge, being completed in three phases as follows:

• Phase 1; dredging of the Preparatory Pilling Area (Berth 52) to a depth of -3m CD, carried out in a series of northwest to southeast transects.
• Phase 2; dredging of the transition slopes to the Dredge Pocket Extension (Berth 53).
• Phase 3; dredging of the Dredge Pocket Extension (Berth 53) to -10m CD.

The dredging platform regularly moved between both the pilling area and transition area in order to maximise loading according to tide state and the weather/sea conditions present.

The dredged seabed comprised a sand/silt (c. 40%/60%) of medium compaction, light to dark grey/black in colour, overlying a compact silty-clay, medium-dark grey in colour. In addition, crushed shell, gravel, and pebble inclusions were frequently encountered. Building material, including concrete blocks/reinforced concrete slabs, was frequently encountered when dredging near to the shoreline; this area of the port comprising land that was reclaimed in the 1990s.

Archaeological monitoring observed and recorded the dredging process, inspected any objects that were brought to the surface by the dredging operation.

No archaeological or historically significant material was encountered. The majority of the dredging work did not impact seabed strata to any significant depth (-3m CD). Deeper levels (-10 CD) were dredged within Berth 53 (Dredge Pocket Extension) and an increased archaeological potential for these layers was anticipated. However, the dredge material form this particular location also proved to be archaeologically sterile in nature.