Britannia Bridge stonework to be bolstered over long-term collapse risk:
FEARS CROSSING WILL DETERIORATE OVER TIME
PLANS have been unveiled to bolster stone work on the Britannia Bridge to shore it up against potential ‘catastrophic collapse’ of its iconic towers.
The bridge is the main road and rail link between Anglesey and the mainland.
It suffered a major fire in 1970 and was re-opened to traffic in 1980, and a new road deck a level above the earlier rail tracks was installed.
It currently carries most of the 46,000 vehicles that cross the Menai Strait every day and forms a major part of the A55.
But with fractures, first spotted in 1984, being reported on parts of the stone masonry lintels on its three iconic towers, plans have been submitted to install new beams to support the structures which are as old as the 1850 Grade II listed bridge itself.
According to the application, which has been submitted to Anglesey Council’s planning department, there’s a risk that the condition of these stone lintels will continue to deteriorate with time, although they are said to currently be in a “stable state” and constantly monitored, with the risk of collapse described as “low”.
As the problem will potentially lead to the “partial or total collapse of the sections of the tower”, owners Network Rail plan to install the beams to catch the stone lintels “should they fall”.
Similar plans were originally approved by council planners in 2015, but with the original permission now nearing its five-year time limit, the applicants have presented slightly amended plans.
The planning documents state: “Whilst the risk of the lintels collapsing is minimal, Welsh Government has tasked Network Rail with implementing a means by which to mitigate any potential risk of collapse of the lintels in the future.
“This recognises that any failure of the lintels would have catastrophic implications for road users and would result in the immediate closure of Britannia Bridge.”
Deciding that fibre reinforced polymer (FRP) beams under the lintels of the towers is the most suitable solution, Network Rail says that the beams would be designed to ensure “a consistent visual appearance in relation to the listed bridge” and can match the colour of the stonework on the towers.
Owned by Network Rail, the cost of any maintenance or repairs to the bridge is shared with the Welsh Government.
The three land towers, which would see the new beams fitted on, are known as the Anglesey Land, Britannia and Caernarfon Land towers.
The bridge is thought to have been called ‘Britannia’ due to a corruption of the name of the rock in the middle pillar on which it was built on – ‘Carreg y Frydain,’ which sounds similar to the Welsh word for Britain, ‘Prydain’ but instead refers to the ‘turbulence’ or ‘effervescence’ of the Menai Strait in which it stands.
The documents supporting the application conclude: “The proposed FRP beams and their brackets will have minimal impact upon the visual appearance of Britannia Bridge’s towers and will provide a suitable solution to ‘catching’ any masonry should the lintels fail.
“It is considered that the proposed installation of the beams will not adversely affect the character or appearance of the listed bridge and will not compromise the features of the bridge’s Grade II listed designation.”
It’s expected that Anglesey Council will consider the listed consent application over the coming months.