Nicholas Street Viaduct inspection
Post-Tensioned Structure Inspection (PTSI) – Nicholas Street Viaduct, St Martin's Way, Chester
Contractor – Balvac
Latest update:
Delays expected – six-week works programme
- Sunday 21 September – the viaduct will be totally closed in both directions between 8pm and 6am while contraflow arrangements are put in place.
- From Monday 22 September – the inside carriageway of the viaduct will be closed between the Fountains Roundabout and the 1966 bridge on St Martin’s Way. A contraflow will be in place with both inbound and outbound traffic using one carriageway, so delays are expected, particularly at peak times, please avoid the area if possible.
To enable traffic to rejoin the carriageway safely when it opens up after the 1966 bridge, King Street will also be closed at its junction with St Martin’s Way.
[After approximately three weeks the works will reverse and the outside carriageway will be closed with a contraflow in place on the inside carriageway between Fountains roundabout and the 1966 Bridge. When this is in place, City Walls Road will be closed at its junction with St Martin’s Way (after Brennus Place) – further updates will appear on this page regarding when the switch is going to happen.]
When?
The programmed dates for these contraflow works on the inner ring road are from 21 September 2025 until 31 October 2025. If anything changes we will provide updates on this webpage.
Background
Nicholas Street Viaduct is a thirteen span post-tensioned structure that carries the A5268 inner ring road in Chester over side roads, the canal and the main Holyhead railway. The 300m long viaduct was opened in 1966 and extends from the City Walls at St Martins Gate to the Fountains roundabout at the north end of Upper Northgate Street.
What is a post-tensioned bridge?
Post-tensioned bridges use high strength steel tendons embedded in the concrete structure. A special inspection is required to check on the condition of these steel tendons.
What is needed?
The detailed inspection involves breaking out the small areas of concrete to allow the steel tendons to be viewed and inspected. This work needs to take place in various locations, on the top of the bridge, and to the underside including the sections over the railway, the canal and the side roads.
To allow the inspection to the top of the bridge a contraflow will be required, to close off each side of the viaduct in turn, to allow the work to be carried out safely. Two-way traffic will be maintained, but there will be delays in the area. It is anticipated this element of the work will take approximately six weeks in total to complete. Also, City Walls Road will need to be closed at its junction with St Martin’s Way, with access to properties and emergency vehicles being maintained from Watergate Street.
Work to be carried out at the same time
Expansion movements to this large structure are accommodated by carriagway joints at both the south and north ends of the viaduct. These joints are deteriorating and will be replaced with new joints as part of the inspection works. In addition, the drainage gullies over the structure will be jetted to ensure that they are functioning properly.
Work underneath the structure
An inspection to the underside of the structure will also take place over the coming months and this will require short closures of side roads – Canal Street and Garden Lane, access to the Council-owned car park on Garden Lane, as well as to private land. The inspection to the section over the railway will need to be carried out with approval from Network Rail, overnight, when access is available to the railway.
