The Welsh Government and its contractors have identified a preferred method of replacing the hangers on the Menai Suspension Bridge but need to test the methodology before proceeding.
A Welsh Government spokesperson told Highways that its contractor has designed a method to de-stress, remove and replace each hanger, 'developed to ensure a safe and efficient way of carrying out the necessary work to bring the bridge back into full use, without needing to modify the structure of the bridge, recognising its local, national and international heritage'.
The bridge, which links Anglesea to the mainland, was closed to all traffic in October after a 'structural concern' was identified by engineers.
It was re-opened to 7.5-tonne vehicles earlier this month after temporary works were completed.
However, in a written statement Lee Waters, deputy minister for climate change, said a final phase of work, in which all the hangers on the bridge will be replaced, must be delivered before the bridge can be re-opened to all traffic.
Mr Waters said: ‘A preferred method of working has been identified that will minimise further disruption, but this methodology must be tested before we can finalise the project programme.
‘This means we will need to temporarily close a lane on the bridge to allow engineers to work safely and test the proposed hanger replacement system.’
The trial will begin on Monday (6 March) and is planned to be completed within four days, although Mr Waters said this could take longer if there is severe weather or ‘another unforeseeable setback’.
Part-time traffic lights will operate at each end of the bridge when a lane is closed, allowing vehicles to cross in either direction alternately.
Mr Waters said the lights will only be in use between the hours of 9am and 3pm, Monday and Thursday.
In January, the minister said he had asked the North Wales Transport Commission to consider the resilience of access to and from Anglesea ‘in light of the recent closure of the Menai Bridge’.
Earlier this month, he announced that a planned Third Menai Crossing will be assessed by the Commission, but is ‘not happening any time soon’.
The Commission, which was set up last year, is likely to recommend a package of transport improvements for movement between Anglesey and the mainland.
