York Historic Environment Record

This major archaeological project took place during the demolition and reconstruction of Layerthorpe bridge between 1995 and 1997. Two trenches were excavated archaeologically. An archaeological watching brief was maintained within a further 8 separate trenches and 7 separate areas. Roman period Excavations in trench 2 within the carriageway of Peaseholme Green revealed a sequence of deposits associated with pottery and tile production in this area in the Roman period (from 100AD to around 300AD approx). Deep dumps of ash, kiln waste, and tile and pottery wasters were excavated, with deposits surviving at only 300mm below the existing surface. The finds included a range of pottery types rarely seen from excavations. About 20000 sherds of tile, pot and kiln furniture were recovered. In the trench within the river bed (trench 1), a small sondage was cut through the deposits below a pre-conquest clay bank, revealign a post alignment and layer of cobbles. When interpreted alongside the resupts of probing undertaken by divers on this site, it appears that this cobbled layer extends across the river and covers a wide area. The excavated element produced Roman pottery. It seems likely that this may represent a significant Roman river fording point. Trench 1 pre-1067 use of the River Foss In 1067 a dam was built on what is now the site of the Castle Mills Bridge. This dam was built as part of the works to create a set of water defences for York Castle. A by-product was the flooding of a significant part of the Foss valley from Castle Mills all the way to what is now Foss Islands Road and well beyond. Two mills were destroyed and a very large artificial lake, subsequently called the Kings Fishpond, was created. Excavations in trench 1 revealed a pre-1067 riverside sequence. A clay bank revetted with wattle and a timber-revetted clay and cobble structure point to extensive water management works in the Foss Valley. These may have been associated with a mill or might have been used as part of the leather preparation process. These again are very significant finds. This is the first time that 11th century water management features have been excavated in York. Medieval Bridge The demolition of the 19th and 20th century bridge structures revealed extensive timber foundations which were excavated on the site of the east abutment. These foundations consisted of a series of vertical oak piles driven into the alluvial silts of the Kings Fishpool and underlying river silts. A total of 77 piles were recorded in Trenches 7 and 8. They were between 1m and 1.85m in length and between 200mm and 250mm in diameter. One end had been shaped to a point. The piles were arranged approximately in rows. On top of the piles was placed a series of pegged timber beams and planks. Significantly, the major beams appear to have been reused from an earlier structure, perhaps a building. Material dumped between the piles suggests a 15th century datre for these piles.