Site Event/Activity record ECH5226 - Watching brief at Bluecoat Square, Chester in 2005

The archaeological watching brief encompassed an area parallel to the southern site boundary, a sandstone wall, to the rear of the school building measuring c.7.0m north/south by approximately 9.0m east-west. This small plot had, prior to the watching brief, been occupied by a single story brick building containing a series of toilet cubicles. The watching brief was carried out following the demolition of this building and during the subsequent excavation of the underlying soil deposits to an overall agreed foundation depth of c.800mm. The results of the watching brief undertaken to the rear of the Blue Coat school, Upper Northgate Street, Chester, have demonstrated unequivocally that significant archaeological features and deposits survive within the excavation area. These archaeological features and deposits include a probable sandstone road surface (9) which may be part of the c.5.9m wide patrol-track which is known to have circumvented the fortress defensive ditch (Mason, 2001, 101). The linear feature encountered to the south of the exposed surface my possibly be its southern road-side drainage ditch. A series of soil deposits sealed beneath the sandstone surface, contexts (14), (15), and (16) contained Roman pottery sherds of 1st to 2nd century date along with fragments of ferrous metal and possible copper-alloy metal working slags. The presence of these soils beneath the sandstone surface suggests that the surface itself may belong to a later phase of the development of the fortress, perhaps during the later 2nd or 3rd centuries. These earlier soil deposits and any features which may be sealed beneath the sandstone surface have the potential to throw significant new light on the development and use of the land immediately north of the fortress defensive ditch. Samples of these soils were taken for possible future analysis. Clear evidence for the abandonment and disuse of the sandstone surface was provided by the accumulation of a soil deposit (8) immediately above it along with a thin band of black soil (7) which almost certainly representing a layer of decayed vegetation. This accumulation of soil indicates a protracted period of low-level occupation within this area. A sample of context (8) was taken for future analysis. The soil deposits which formed above the sandstone surface were themselves sealed beneath a further soil accumulation which contained some large sherds of Roman pottery and ceramic roofing tile. This soil layer (6) may represent renewed occupation outside the fortress but may also represent dumping of soils and mixed material perhaps for agricultural reasons or as a deliberate attempt to raise ground levels perhaps for building purposes. The general mix of 1st-2nd century pottery recovered from this context certainly suggests that this soil has been redeposited. Context (6) had been truncated by a linear cut (3) which had effectively removed context (6) from the southern half of the excavation area. This cut had then been filled, perhaps deliberately, with a dark grey-black soil (4) which contained many sherds of pottery dating from the mid to late 18th century with a few dating to perhaps the early 19th century. Context (4) may represent a post-medieval garden soil although the exact reason for the cut is uncertain. Surprisingly, no clear evidence for medieval soil deposits or features were encountered during the watching brief. This may well be due to the later post-medieval removal of deposits as indicated by cut (3) along with the destruction of buildings during the Civil War of the mid 17th century. The crushed sandstone deposit (31) encountered within the sondage excavated close to the southern site boundary wall may represent an earlier Roman surface perhaps a precursor to surface (9). Alternatively this deposit may be a continuation of context (9), the difference in level being due to the areas topography, but if this is so then it is unlikely that the linear feature encountered on the south side of surface (9) is in fact its associated drainage ditch. Clearly only further, more detailed, archaeological investigations need to be carried out here in order to establish the true nature of these sandstone surfaces. Construction and subsequent destruction of brick-built structures of the 19th century were indicated at by a brick foundation (26) encountered on the west side of the excavation area. This footing once supported an external staircase which climbed the wall of the southern wing of the 19th century brick alms houses which still occupy the land to the rear of the Blue Coat school. This staircase is shown on the ??? Town Plan of Chester and the scar for these stairs is still visible. The position of the stairs suggests that they once formed access to a terrace at first floor level on the rear of the properties. Within the eastern half of the excavation area, and continuing beyond it, a brick-built structure with sandstone foundations was encountered. This structure had at its west end a apse-like cubicle containing a brick floor. Corroded metalwork at the base of this structure suggests that it may have contained a mechanical structure or fitting. The function this structure provided is currently uncertain but it is likely that it may be associated with a laundry or other hygiene facility. Following recording, a layer of protective membrane was laid over the exposed sandstone surface (9), prior to the excavation area being covered in imported stone, as a mitigation exercise in order to protect the surface for future analysis.