PLANS TO REPAIR BRITAIN’S LONGEST BREAKWATER BEING DRAWN UP
HOLYHEAD’S port could become unusable if action is not taken to repair its breakwater.
The structure, which is 1.7 miles long and took 28 years to build, is gradually eroding.
But if it is not repaired, the port could be closed within the next 15 years.
Stena Ports has been carrying out day to day maintenance of the structure, but the costs of that are running at around £150,000 a year.
The mound of rubble is being worn away by waves, and experts believe it could be breached within 15 years.
Plans to repair the breakwater – the longest in Britain – are now being drawn up.
A planning application states: “The breakwater forms part of the essential infrastructure for the operation of the Port, providing shelter from a more extreme wave climate to the berthing ferries and other vessels.
“Without the breakwater it is likely that the wave conditions would increase to the point that the operation of the ferries is no longer viable, resulting in the closure of the port and the loss of the international link to Ireland for Wales and England.”
In 2017, with Welsh Government and Stena Line Ports support, an outline business case was
put together to develop options for the refurbishment of the breakwater.
These varied from doing nothing, which would result in the failure of the breakwater, to strengthening the existing structure, constructing an offshore breakwater and restoring or topping up the rubble mound.
The proposed refurbishment scheme is being jointly developed by Stena Line, Anglesey council and the Welsh government but the actual works to the breakwater would be led by Stena Line.
The planned refurbishment of the seaward side of the breakwater comprises two layers of 20m3 Tetrapod concrete armour units of between 40 and 55 tonnes and an outer, single layer of 60 tonne Chevron concrete armour units. Meanwhile on the leeward side of the wall, an Articulated Concrete Block Mattress would be placed over a distance of approximately 10-15m from the leeward side of the wall to prevent any further erosion of the rubble mound and undermining of the wall. It is unknown at this stage if the works would be carried out in a single stage between March 2020 and January 2022, or a three phase project lasting until October 2026, which is largely dependant on the available funding.
The report adds: “Once the refurbishment is complete, further maintenance of the rubble mound would be minimal and less than the maintenance activities that are currently being undertaken.
“Wave overtopping of the structure will still occur, but at a lesser extent, and as such ongoing repointing and repair of the wall may still be required. The structure would continue to be monitored annually and repairs undertaken if damage occurs.”
The breakwater was built using rubble from the northern side of Holyhead mountain.
It was opened in 1873 by Albert Edward, Prince of Wales, after an 1847 Act of Parliament. It took 1,300 men more than 28 years to complete, and is Grade II listed.