Building record 12000/10/3 - Chester City Walls - Wall between Morgan's Mount and Northgate: Steps to the West of Northgate

<1> Earthworks Archaeological Services, 2013, Investigations into the Condition of the City Walls, Close to the North Gate Steps, Chester, R3488 (Client Report). SCH7180.

In November 2012, archaeological investigations were undertaken at Northgate Steps, west of the North Gate, in advance of remedial works. Six trenches were excavated in order to assess the character, significance and date of the deposits and structural remains. A watching brief was also maintained during the limited and controlled removal of masonry from the north and south elevations to the City Walls.

Trenches 3 and 4 (Area 2), investigated the construction of the steps. Trench 3 was located at the base of the steps and entailed removal of the three lowermost stone treads. This revealed the two flanking walls of the steps and the inner core. The south wall was constructed from a single skin of sandstone ashlar blocks measuring circa 0.16m thick; the details of the north wall were obscured by mortar. The core material comprised large, angular blocks of sandstone towards the base of the steps structure with smaller fragments of sanstone bonded as a mass with cream-brown, lime-based mortar beneath the treads. Removal of the large, lower blocks revealed a bedding layer composed of angular sandstone set on edge at a depth of circa 0.45m below the current road surface. Trench 4 entailed the lifting of three stone treads towards the top of the steps. The two flanking walls and core material were revealed as for trench 3. Significantly, a gap of 0.2m wide was evident between the face of the north wall of the steps and the inner face of the City Walls. The gap had formed over time and a sheet of mortar that had been used to bond the two sturctures had detached and fallen down into the void. The gap between the steps and the City Wall was bridged by the existing treads indicating that they had been replaced.

Trenches 1 and 2 were located on the walkway of the City Wall. Results here also demonstrated that the steps and City Wall structures had been separating for a considerable period. A void between the two structures was recorded which had been historically packed with sandstone blocks and rubble. The movement of the steps from away from the City Wall had also resulted in the dislodging and splitting of some of the ashlar blocks of the inner face of the City Wall. Trench 2 also revealed a roofed chamber incorporated into the City Wall. At this point, the City Wall itself was of thinner build and lacking in situ facing blocks implying that it had been cut back at some point, potentially with the construction of the chamber or potentially, in the eighteenth century when cottages were erected against the City Wall (see source 2).

Trenches 5 and 6, located at ground level close to the west end of the steps, revealed grey clay deposits, at very shallow depth. This clay deposit is considered to be the rampart to the Roman legionary fortress.

<2> Matrix Archaeology, 2013, Northgate Steps, Water Tower Street, Chester Archaeological Assessment, R3487 (Client Report). SCH7179.

Following on from the archaeological evaluation of the steps structure and City Wall done in 2012 (source 1), further documentary research was undertaken. Both cartographic and documentary sources indicate that the steps on both the west and east side of the North Gate date to the early nineteenth century. There is evidence that the walkway of the City Walls was not interrupted by the old Northgate, as it is depicted on a 1745 city plan as continuing around the outside of the gate. Other evidence includes the City Assembly minutes for 15 March 1810, which record that, ‘... Fifty Pounds shall be allowed by the Treasurers to this Incorporation to the Murengers of this City towards erecting two flights of steps at the Northgate’. The fact that these steps were the subject of a separate order to that of 1808 which authorized the demolition of the old Northgate and the commissioning of the new implies that they were not part of Harrison’s original design. This is also suggested by Harrison’s architectural drawing for the gate which does not include steps. Instead, the steps would appear to have been an initiative of the Corporation, ordered once the new gate was either complete or nearing completion, circa 1810.

Cartographic (1875 Ordnance Survey plan) and pictorial evidence (McGahey, 1855) also demonstrates that a pair of cottages was erected against the inner face of the City Wall by the City Council. When the steps structure was constructed on the west side of the North Gate, the new lower landing was contiguous with the east gable of one of the cottages. It is thought that the external doorway of the cottage was originally located at the north end of its east gable, hard up against the City Wall (this location would have been more practical than the south wall due to the narrowness of the street here). Construction of the steps structure would have resulted in the doorway to the cottage being blocked, hence provision for a new doorway and passage beneath the landing, allowing access to the original doorway. Following demolition of the cottages in 1877, the city wall was thickened substantially, and this included an open chamber with a large, arched doorway, of unknown function. Probably in the early 20th century, this door was blocked up, resulting in the present appearance of the wall.

<3> Earthworks Archaeological Services, 2018, Northgate Steps, City Walls, Chester: An Archaeological Watching Brief, R4271 (Client Report). SCH8626.

An archaeological watching brief was undertaken between June 2016 and April 2018 during the dismantling of the steps leading to the City Walls, to the west of North Gate. This work followed on from the programme of investigation of the steps structure described above (sources 1 and 2) which revealed that they had been separating from the City Walls for some considerable time.

Dismantling of the steps structure confirmed the results of earlier investigations. The outer leaf of the steps was constructed from ashlar sandstone masonry the foundation of which sat upon the bedrock geology towards the east end of the site (following the partial removal of elements of the surviving Roman foundations) and, beyond this to the west, in a trench cut into the remains of the Roman rampart. The space between the outer leaf of masonry and the internal face of the City Wall was infilled with brown sand and fragments of sandstone loosely bonded with a lime mortar to form a core. Amongst this core material finds of pottery, glass and clay tobacco pipe, all of late post medieval date, were recovered. Towards the east end of the steps structure, and at a depth a little below current pavement level, a levelling layer, consisting of re-used brick, had been inserted. This material was perhaps inserted as a means of forming a firm and level surface prior to raising the structure above the surrounding ground level. Occasionally, blocks of masonry within the outer leaf of the steps structure were turned through 90° in order to key the structure and core material together. Towards the west end of the steps the core material was loosely but directly bonded to the core of the existing eighteenth century City Wall, any pre-existing masonry to the face of the City Wall having been removed at this location; this probably occurred during demolition of a cottage building that had previously occupied this area (as indicated by the presence of lime plaster render on the face of the City Wall on removal of the steps structure). It was at this very point where the stability of the steps structure and the City Wall had failed.