Birkenhead Town Centre Redevelopment, Plot A

The scheme of mitigation, set out within this section, followed the methodology within the approved WSI which referenced guidance set out in CIfA's Standard and Guidance for an Archaeological Watching Brief (2020). The definition of an archaeological watching brief by CIfA is as follows: "A watching brief is a formal programme of observation and investigation conducted during any operation carried out for non-archaeological reasons. This will be within a specified area or site on land, inter tidal zone or underwater, where there is a possibility that that archaeological deposits may be disturbed or destroyed. The programme will result in the preparation of a report and ordered archive." In relation to the works within the Site, the archaeological watching brief observed specific construction groundworks in accordance with the WSI. In Phase 1 these comprised: " a north-south sewer diversion. and " excavated pits for pilings. The Phase 2 works consisted of: " an east-west sewer diversion. and " pile caps. Photographs were taken showing all the areas that have been observed during the watching brief for the record. Recording of archaeological deposits included: " a proforma context record for each archaeological deposit that can be identified within the areas of the watching brief e.g., buildings/walls. " a Harris Matrix diagram to elucidate any complex stratigraphic sequences. " site plans, either DGPS-recorded, or hand-drawn at a scale of 1:100, and depicting: - the extent of the mitigation area, tied into the Ordnance Survey National Grid and located on a 1:2,500 scale plan. - the extent of all stratigraphic units revealed; and - appropriate detail identified within stratigraphic units. " plans of stratigraphic units at a minimum scale of 1:20, unless specific circumstances dictate an optimal scale. " sections of stratigraphic units at an appropriate scale. Unless specific circumstances dictate an optimal scale, then this should be a minimum of 1:20. For areas of detailed, significant or complex stratigraphy the scale used should be a minimum of 1:10. " a photographic record comprising recognised industry-quality digital SLR photographs, with a minimum resolution of 10 mega-pixels and saved as high quality .jpg files.;3 " numerical indices of all context records, drawings and photographs, checked and cross-referenced as necessary; and " a diary record of the progress of the archaeological work, including details of liaison and monitoring meetings, site visits, and a record of staff on site. The watching brief monitored ground disturbance of construction activities related to groundworks which included the grubbing out of the previous foundations of the precinct buildings, excavations for services, the excavation of a sewer diversion trench and for the excavation of a series of pile caps. Following this method of observation and recording the Site largely appears to offer a poor state of preservation for archaeological remains. The suspected levels of disturbance were undeniably very substantial across the site, with large areas observed to having been dug out to depths exceeding 3.00m in places, with the excavations from the 1970s also having cut into the natural clay beneath by some margin. This was done in order to facilitate the massive concrete foundations of the former shopping precinct, which were intermittently observed (through the excavation of the test pits) to persist in a linear arrangement along the western and eastern sides of the development area. Furthermore, the areas surrounding these bases appear to have been excavated into large open areas, no doubt in order to facilitate the construction of timber shuttering for casting of these bases - meaning large areas of the site had been rendered archaeologically inert by the severity of these historic works.