In 2015, the clients commissioned NAA to conduct a desk-based cultural heritage appraisal for a scheme to renew water services in North Yorkshire. NAA identified a number of archaeologically sensitive areas and recommended various watching briefs and evaluation excavations to mitigate the loss of potentially important archaeological features. As the A66 is thought to lie directly on top of a former Roman road linking Roman Dere Street at Scotch Corner to the Roman fort Lavatris at Bowes, and across the Pennines into Cumbria, it was considered possible that the pipeline renewal route between Carkin Moor Roman Fort and West Layton may encounter truncated remains of this road, therefore archaeological monitoring was advised. It quickly became apparent that the pipeline easement along the route of the A66 had not only encountered remains of the former Roman road but also associated roadside features. As a result, the archaeological monitoring was upgraded to a full excavation which uncovered a previously unknown late Roman roadside settlement. A section of the pipeline route at Mainsgill Farm was directionally drilled in order to avoid disruption; therefore, only the excavation of the launch pits was observed as part of the archaeological works.

Significant deposits from the Roman period were encountered including six roadside enclosures – two of which had been walled – separate cobbled surfaces distinct from the Roman road, the footing for a possible building, wheel ruts and drainage gullies, occupational refuse dumps and, most significantly, a pottery kiln comprising bowl, flue and stokehole pit and a with a secondary flue exiting the site to the south.

It was clear that the kiln had been abandoned as it contained a large assemblage of pottery, predominantly of items constituting the final firing, along with some material associated with general waste and deposition of pottery from the site. The most likely cause of the misfiring is that the quantity of kiln furniture was not sufficient, resulting in the pots not being fully fired. One possible explanation was that the fire got out of control or was left unmanaged, resulting in irreparable damage to the kiln and the pots. A large assemblage of charcoal was recovered from the kiln and stokehole, the majority of which was heather, that was probably the remains of fuel burnt to fire the kiln. Heather is a fast-burning fuel that generates a great deal of smoke when it combusts so it is not suitable for a long, slow burn at a consistently high temperature. Heather was used to fire kilns, however, usually as part of the initial process to aid the harder woods to burn or, later during the process, to create a reduced atmosphere within the kiln. The kiln products dated from the later 3rd century and through the 4th century AD.

The Roman fort, along with the settlement, would have provided an immediate market for the pottery; with the road providing a constant supply of trade across the Stainmore Pass, and connection to the wider road network. Gritty grey ware jars in the Carkin Moor ‘tradition’ have been found at other nearby sites including forts at Greta Bridge, Bowes and Piercebridge and the town at Catterick. Geophysical survey conducted to the south-west of the site, to aid characterisation of the excavated features, revealed more of the excavated roadside enclosures as well as the presence of another kiln associated with the secondary flue and at least one further possible kiln feature. It is conceivable that this pottery-production site operated as a ‘satellite’ workshop to those situated at Catterick to the east.

These archaeological features suggest the existence of a hitherto unknown industrial and settlement centre related to the Roman fort to the east. The presence of the kiln represented the only evidence of pottery making on the entire length of the Stainmore Pass between Catterick and Penrith. In addition, the very rare finding of a Romano-British pottery kiln with a large quantity of vessels that were fired in the structure has offered the opportunity to investigate pottery production and supply in the north.