Eric Wright Civil Engineering is working alongside Cheshire West and Chester Council to renovate the Roman walls and historic Northgate Steps
Movement has been detected in the structure of the Northgate Steps. The steps are a Grade I listed structure and form part of the Chester city walls which is a scheduled monument.
In 2015, the council dismantled Northgate Steps due to them moving away from the city walls. During the work, complications with the archaeology below ground and the stability of the walls were revealed. A temporary propping has been installed to ensure the wall and foundations remain stable during dismantling.
The city wall will remain propped until the work is completed in spring 2020 to ensure public safety.
Planned work on the Roman walls
The dismantling work revealed the issues were associated with the variability of the foundation conditions along the structure. The Northgate Steps were founded on the soft, organic Roman rampart material, which was once part of the original city fortifications.
The lower flight of the steps were founded partly on rock and partly on the original Roman Gate footings. The inner leaf of the City Wall was also founded on poor-quality ancient rubble.
The stability of the Roman walls is currently reliant on the temporary propping. Relevant precautions will be taken to ensure that the monument is protected throughout the duration of the works.
Eric Wright Civil Engineering will reinstate Northgate Steps to become structurally independent of the City Wall. It will also provide underpinning to the inner leaf of the City Wall over the extent of the exposed Roman rampart. This will allow the steps to be dismantled without compromising the stability of the walls. A stainless-steel framed viewing chamber in the steps will also be included.
All excavations are being hand dug and overseen by a team of archaeologists appointed by the Council. The work is being phased to ensure stability of both the excavation sites and the structure.
Diane Bourne, managing director for Eric Wright Civil Engineering, said: “It was clear from the observed movement that the issue lay with the differing foundation levels and now that excavation work has been done we can see that the problem goes back to the original Roman city defences.
“We will be taking all necessary precautions to ensure that the monument is protected throughout the duration of the works.
“The Northgate Steps and City Walls are world-famous and we are very proud to be working with Cheshire West & Chester Council and Historic England to ensure this site remains a proud feature of Chester for many more years.”
Councillor Karen Shore, deputy leader and cabinet member for environment, highways and strategic transport at Cheshire West & Chester Council, added: “The rebuilding needs to take place with as little damage as possible to the precious archaeological remains.
“Eric Wright Civil Engineering is keen to engage with local businesses and residents and will take all possible measures to minimise noise, intrusion and inconvenience to those closest to the site.”