Engineers have spent the last three months working on the €4.3m automated hydraulic storm gate project at the mouth of the North Harbour on Cape Clear, Ireland’s most southerly island, about 10km off Cork.
The firm successfully towed and installed a contractor-designed, 1,000-tonne, reinforced concrete lock chamber for the new storm gates from its casting basin in Verolme Dry Dock in Cork Harbour some 100km to the island last September.
The chamber was then sunk and fixed onto a prepared concrete base.
Work has been ongoing in recent weeks to tie the quay on each side of the structure into the chamber, to seal and anchor it with grout, and to install the electrical and hydraulic systems.
Project manager Paul Fitzgerald confirmed that the 12m by 8m gates, which will be responsible for blocking storm surges, will be fitted in mid-February and should be operational by early March.
Commissioned by the Department of the Marine, the gates are designed to close rapidly and close off the inner harbour, protecting the island’s boating fleet during severe storms.
They need a substantial concrete structure to accurately hold and align them, in a water depth varying from 4m to 8m.
The works are part of a €4.3m development which includes a 70m slipway, the replacement of the Bull’s Nose structure incorporating a storm gate, and an extension to the end of Duffy’s Pier. Excavation, dredging, and reclamation works will also take place, including the construction of an armoured embankment at the seaward side of the new Bull’s Nose structure.
It also involves a reconfiguration of the harbour entrance.
The Bull’s Nose plays a crucial role in the protection of the harbour from swells and waves.
It has been deteriorating for some time and an attempted repair in 1999 involved grouting and reinforcing.
In 2005, the breakwater pier and Bull’s Nose were used as the main landing pier for the island while reconstruction works were being carried out at Duffy’s Pier.
Further deterioration of the structure may have occurred at that stage.
At the time the project was commissioned in late 2013, there were several major vertical cracks all around the structure, with the pattern of cracking suggesting that the structure was subsiding in a south easterly direction.
In 2009, the department prohibited berthing at the Bull’s Nose and banned heavy vehicles from using the structure to prevent potentially destabilising loads amid concerns that the entire structure was at risk of collapse.
This major infrastructural project will, however, significantly improve shelter within the outer basin of the North Harbour
Shane Ó Drisceoil, a skipper on the Cape Clear Island Ferry Company’s Dun an Óir vessel, said islanders are confident that, once complete, the storm gates structure will protect the island from whatever Mother Nature throws at them.
“It’s something the island has needed for years. It will provide great protection for the harbour,” he said.
Cape Clear bore the brunt of last February’s storms and suffered extensive structural damage.
February’s huge storm surge sent giant waves crashing in to the North Harbour, causing extensive damage to already weakened quay walls.
The island’s lesser used South Harbour was also damaged, with waves crashing in to the harbour, smashing through a ditch, and flooding the island’s hostel.
Locals in their 80s described it as the worst storm in living memory — the battered island was ranked as one of the worst storm-hit areas in Cork.
But the storm gate project had already been commissioned by the department and site work was due to start within weeks of the storms hitting.
Mr Ó Drisceoil said that, once finished, it will make a huge difference to the island.
“There are people on the island in their 70s and 80s who said they had never seen anything like it last year,” he said.
“We would normally miss an average of five or seven sailings during the winter months due to bad weather.
“But last winter, we missed the most sailing days in modern times — we missed up to 17 sailings because of the bad weather.
“We had storm protection in the North Harbour before. You’d have to place up to 12 timber booms, one by one, in the harbour. It took up to an hour to get them in place.
“Then about 10 or 12 years ago, a crane was installed to drop the booms in place which reduced the time to about 40 minutes.
“But this new storm gate is bigger and higher and further out, which will give even greater protection, and enclose a larger area of the inner harbour.
“It was a big operation with the old system, and you’d have to lift the booms up again to let a boat in or out.
“This new system will be so easy to use — with just the push of a button it will all be done in just a few seconds.”