Geophysical Survey at Hinckley National Freight Interchange

1 A geophysical (magnetometer - gradiometer) survey will be carried out across all parts of the two survey areas which are suitable for magnetometer survey, an area of up to approximately 29ha. 8.2 The survey will be undertaken using four Bartington Grad601 sensors mounted at 1m intervals (allowing for a 1m traverse interval) onto a rigid carrying frame. The system will be programmed to take readings at a frequency of 10Hz (allowing for a 10-15cm sample interval) on roaming traverses spaced 4m apart. These readings will be stored on an external weatherproof laptop and later downloaded for processing and interpretation. MLGrad601 and MultiGrad601 (Geomar Software Inc.) software will be used to collect and export the data. Terrasurveyor V3.0.37.0 (DWConsulting) software will be used to process and present the data. 8.3 The magnetometer system will be linked to a Trimble R8s and R2 Real Time Kinetic (RTK) differential Global Positioning System (dGPS) outputting in NMEA mode to ensure a high positional accuracy of each data point. 8.4 A series of temporary sight markers will be established within each survey area using a Trimble dGPS system. The markers will guide the operator and ensure full coverage with the magnetometer system. 8.5 At the start of each day the magnetometer will be left idle whilst switched on for approximately 30 minutes to allow the instrument to acclimatise to the site conditions. The instrument will thereafter be balanced when necessary and at least twice during the day. 8.6 The survey is expected to commence on May 17th 2021 and to take up to 2 weeks with a single team of surveyors. A draft report will be issued to the Client within 3 weeks of completion on site. Headland Archaeology (UK) Ltd was commissioned by the Environmental Dimension Partnership on behalf of Cotswold Archaeology, to undertake a geophysical (magnetometer) survey at one of two locations near Hinckley, Leicestershire where improved road connections are required for the Hinckley National Rail Freight Interchange (HNRFI) development. The A47 Link Road Site covered 22 hectares either side of the proposed link road corridor and extends from the proposed new roundabout at the junction with the B4668 in the north-west to the railway line immediately south of Bridge Farm in the south-east. The survey was undertaken to assess the impact of the future development on the historic environment. The results of the survey will be submitted in support of a planning application for the future development of the land and may also inform future archaeological strategy. The spreading of 'green waste' as soil improver over all the arable fields within the survey area (at least 75% of the site) has meant that it has not been possible to assess the archaeological potential of the survey area; the magnitude of the responses from the soil improver will almost certainly be 'masking' the much lower readings from any below ground archaeological features, if present. On the small areas of pasture where 'green waste' has not been spread only drains and modern disturbance have been recorded. No anomalies of possible or probable archaeological origin have been identified by the survey. The archaeological potential of the GSA therefore remains unknown.