The grade I listed, Thomas Telford designed crossing of the Menai Strait opened in 1826 making it the second oldest operational vehicular suspension bridge in the world.

Works by engineering specialist Spencer Group will involve removing, replacing and resurfacing almost all of the footway panels on the approach spans on both sides of the iconic 417m structure.

The project for client UK Highways A55 is estimated to run for 23 weeks and faces challenging environmental constraints due to the Menai Strait’s protection as a Site of Special Scientific Interest and a wetland area of international importance under the Ramsar Convention.

As a result the contractor has developed a methodology to contain all construction work and materials fully on the bridge and avoid any spillage into the water below.

“Early engagement with Spencer Group provided us with workable options to carry out the remedial works,” said UK Highways A55 operations manager Kerry Evans, of CIHT Cymru Wales. “Those early conversations are vital for a client to understand and appreciate the complexity of a project and the path through to delivery.”

The contractor will be using rope access methods to enable it to operate over the side and underneath the bridge deck, 30m above the Menai Strait.

Spencer Group’s sector lead for bridges and structures Luke Fisher said: “The Menai Suspension Bridge is covered by highly stringent environmental constraints and, of course, it’s of paramount importance that we take the greatest care with the fabric of this iconic structure.”

Each footway of the Menai Suspension Bridge will be closed while work takes place, with pedestrians directed to use the path on the opposite side of the structure during this time.

(Photograph: bvi4092 and licensed for reuse under this Creative Commons Licence)