The 2006 assessment noted the extensive evidence for industrial production across the region, including the working of iron, lead and copper-alloy, pottery and glass manufacture, and production of leather and salt. The function of the Lancashire and Cheshire nucleated settlements, including Walton-le-Dale, Nantwich, Middlewich and Wilderspool, in supplying the military in the frontier region has a distinct profile of activity, in which markers such as coarse pottery demonstrate a major decline in the early 3rd century and only low level activity into the 4th.
Since 2006, the great majority of evidence for industry during this period derives from metalworking, particularly iron, which was practised across a wide range of Roman settlement sites. Iron working is the most readily identifiable industrial production process apart from pottery manufacture due to its copious waste products. Minor evidence for iron smithing, possibly of Roman date was recovered from Stormy Point, Alderley Edge (Ch). Traces of evidence for possible Romano-British or medieval iron smithing were recovered along with evidence for medieval activity close by, probably at Saddlebole (Mottershead and Wright 2008).
At Ravenglass (C) iron-working waste, including hammerscale and hearth bottoms, was noted in levelling deposits associated with the east-west road, though no in situ smithing activity was identified. High temperature processes are thought to be industrial in origin, including iron working and possibly also lead, but the source is not clear. One building on the slopes east of the extra-mural settlement may have been associated with metalworking (Cubitt 2015).
Following synthesis and publication of major excavations in Cheshire, production of salt has been identified as an important industrial activity, especially in the ‘wich’ towns of Cheshire, e.g. Nantwich and Middlewich (Arrowsmith and Power 2012; Williams and Reid 2008). Limited evidence for other industries, such as glass, tile and copper alloy manufacturing, has also been recovered.
Further evidence for Roman tile manufacture was recovered in 2005-7 from Ochre Brook, Tarbock (M), in the field to the north of the farmstead enclosure which was excavated in 1993 (Cowell and Philpott 2000). A palaeochannel of the Ochre Brook contained fragments of Roman roof tile and metalworking debris showing the channel began to silt up in the Roman period. A further example of the only dated tile stamp from Roman Britain was recovered (Cowell 2012). Adjacent to the channel was a sandy terrace which had extensive evidence of metal working waste, alongside small abraded tile fragments, interpreted as a smith’s disposal area next to the channel, in hollows and a series of intercutting pits, which also included hammerscale and iron smithing waste. Pottery was scarce (13 sherds) and no structures were found. Nearby two Iron Age pits were found 500 m to the SW of the Romano-British farmstead, providing evidence of thinly dispersed activity across the landscape, indicated the earlier use of the landscape.
At Ribchester (L) excavations in 2016 identified a clay floored building with evidence of use as a workshop in the form of a hearth, kiln fragments, slag, and waste from glass working (S. Stallibrass pers. comm.). The date for this activity is currently unknown.
Rural copper-alloy metalworking waste from a rural site in south Wirral was examined by McIntosh and Ponting (2011).
At Whitley Castle, just over the Cumbria border in Tyneside, a detailed earthwork and geophysical survey of the Roman fort, its extra-mural settlement and field systems has concluded that the fort was constructed to oversee the production of lead and silver (Ainsworth and Went 2009).