Triton Knoll Offshore Windfarm

Geophysical survey and trial trenching along the onshore cable route for an offshore wind farm

Allen Archaeology Limited were awarded a £500,000 contract by Triton Knoll Offshore Wind Farm to carry out metal detection, geophysical survey and archaeological trial trenching works along the entire route of the project’s onshore cable corridor. The works also covered the site of the new substation building, which is to be constructed at Bicker Fen. Work commenced in the summer of 2017 and is currently in its post-excavation phase.

The Triton Knoll Offshore Wind Farm will be located approximately 32km off the Lincolnshire coast and 50km off the coast of North Norfolk and is wholly owned by Innogy Renewables UK Ltd (innogy). When the plant is fully operational it will be capable of generating enough energy for at least 800,000 UK homes.

The geophysical survey consisted of a detailed fluxgate gradiometer survey of the cable route and compound areas, totalling approximately 388 hectares. The cable route runs through a large part of the Lincolnshire fens, and the survey revealed many features which are most likely to represent buried creeks and roddons (the raised beds of former channels), former ponds, pools and marshland. It has also revealed possible evidence of Romano-British salt-making (salterns) and associated water management, and possible settlement activity of a similar date.

Evaluation trenching confirmed the results of the geophysical survey, indicating clusters of late Iron Age or early Roman salterns next to former creeks, and covering several kilometres of the route. Other notable highlights include several late Roman settlements, all located on former roddons where they would be slightly elevated from the surrounding landscape, and fragments of medieval and later occupation. Other areas of the route revealed extended sequences of alluvial deposits with occasional layers of peat and indicate how little of the landscape was suitable for habitation prior to the great drainage works that transformed it into some of the most productive farmland in the country.