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Undersea Cables
Greenlink Interconnector logo
A geophysical survey of the Greenlink Interconnector undersea cable route between Ireland and Wales will be undertaken in the Irish Sea from this week. The environmental video survey, using a drop-down camera along perpendicular transects at 12 stations, with three…
File image of the Van Oord vessel Calypso
The Department of Transport has been advised that Van Oord will perform cable operations on behalf of Nexans for CIDAC as part of the Celtic Interconnector Project. This work will be undertaken along a segment of the undersea cable route…
Department of Transport logo
The Department of Transport has been advised that a geophysical and geotechnical survey will be undertaken by Elettra TLC SpA in Galway Bay, on behalf of Deep Sea Fibre Networks Ltd. The inshore survey work is anticipated to start on…
Power Pact – Irish and Spanish officials mark the signing of an MoU in Madrid to explore a potential electricity interconnector between Ireland and Spain.
Ireland and Spain have taken a first step towards a potential electricity interconnector with the signing of a Memorandum of Understanding in Madrid. The agreement brings together EirGrid and Red Eléctrica, alongside both governments, to explore the feasibility of linking…
Cable Close-Up: Minister Helen McEntee examines subsea cable hardware with Leonard Hobbs during a live demonstration at the Valentia symposium in Co Kerry
The second Subsea Cable Security and Resilience Symposium has opened at the historic Cable Station on Valentia Island, Co Kerry. The three-day event, running from April 22 to 24, brings together international stakeholders from government, industry and academia. Hosted by…
Power Pitch Minister of State Timmy Dooley at the EirGrid stand during WindEurope, where Ireland highlighted plans to accelerate renewable energy and expand grid infrastructure
Ireland’s EU Presidency will emphasise the accelerated deployment of renewable energy, the Government has said. Ireland and Spain are also planning to develop an electricity interconnector. Details of this were outlined on the first day of the three-day WindEurope conference…
EirGrid has announced a major procurement package worth hundreds of millions of euros to support offshore wind delivery. The package marks the first major transmission procurement under its Powering Up Offshore – South Coast programme. It focuses on the Tonn…
File image of the survey vessel Explora
The Department of Transport has been advised that a geophysical and geotechnical survey will be undertaken by Elettra TLC SpA in the Atlantic Ocean off the coast of Co Galway, on behalf of Deepsea Fibre Networks Ltd. Survey works will…
“Deep
The British government claims to have exposed an operation by Russian submarines which were identified as hovering around subsea pipelines and cables in its waters. As The Irish Times reports, British Defence Minister John Healey told a media briefing that…
Eyes Above: Irish Air Corps and Coast Guard aircraft step up patrols over Irish waters as authorities track shadow fleet vessels and monitor risks to subsea cables. Photo: Irish Air Corps/Coast Guard
Ireland faces growing concern over the vulnerability of its subsea cables, with warnings that attacks could sever national internet access. Government departments and State agencies have flagged risks to critical undersea infrastructure, including telecom cables, pipelines and energy interconnectors. The…
Eyes in the Sky: An Irish Air Corps CASA CN235 maritime patrol aircraft conducts surveillance over Irish waters. An Irish Air Corps crew tracked the vessel Arne off the Mayo coast from a patrol aircraft, observing it towing an anchor near sensitive subsea cables in the Atlantic approaches.
A cargo vessel bound for Russia dropped its anchor near critical subsea cables off Ireland’s west coast, according to The Irish Times front page lead story on Saturday, March 28th. The report states that Air Corps personnel observed the vessel,…
“Crew
The cable layer RS Alegranza arrived at Dun Laoghaire Harbour on Dublin Bay on Tuesday (March 24th) and is berthed at Carlisle Pier. Afloat sources indicate the vessel’s visit is for a crew change. It is the second specialist offshore…
Survey push - EirGrid prepares marine and coastal surveys along Ireland’s south coast to support offshore wind development and future grid connections under its Powering Up Offshore programme
EirGrid will begin a new phase of marine and coastal surveys along Ireland’s south coast from April. The work forms part of its Powering Up Offshore – South Coast programme to connect offshore wind energy to the national grid. The…
“Security
Ireland and Britain are to conduct “live” joint exercises to test readiness for protecting undersea cables. As The Irish Times reports, an existing defence agreement from 2015 has been renewed and is “more targeted and focused”, according to Minister for…
The cable-laying vessel Nexans Aurora
The Department of Transport has been notified by Nexans that they will perform undersea cable repair operations for the Celtic Interconnector Designated Activity Company (CIDAC) as part of the Celtic Interconnector Project. The vessel will arrive in the area on…
“Challenge
A research team from Trinity College Dublin (TCD) has been awarded funding for a “next-generation” maritime situational awareness project to strengthen Ireland’s naval security. The Sea-Scan team led by TCD’s Prof Marco Ruffini and Dr John Kennedy and Defence Forces…

Undersea Cables

Undersea cables are vital to Ireland's connectivity, facilitating high-speed internet, telecommunications, and energy transmission. These cables traverse the Irish Sea, connecting Ireland to the United Kingdom and continental Europe, and play a crucial role in global communications.

Submarine Communications Cables:
Ireland is strategically positioned along major transatlantic communication routes. Approximately 75% of transatlantic cables pass near Irish waters, underscoring the nation's significance in global data transmission.
These cables are typically as wide as a garden hose, with the filaments that carry light signals being extremely thin—roughly the diameter of a human hair. They are sheathed in layers of insulation and protection, with cables laid nearer to shore using extra layers of armoring for enhanced protection.

Energy Interconnectors:
In addition to communication cables, undersea interconnectors are being developed to enhance energy security and support the transition to renewable energy sources. The UK has approved the construction of five new subsea interconnector cables to boost the grid's flexibility amidst rising renewable energy. These projects will link the UK with wind farms in Belgium and the Netherlands, and connect England with Germany, Wales with Ireland, and Scotland with Northern Ireland. The cables, with a combined 6GW capacity, are expected to be operational by 2032, increasing the UK's total interconnector capacity to 18GW.

Security Concerns:
The strategic importance of these undersea cables has raised security concerns. Incidents in the Baltics have heightened awareness about the potential risks to subsea infrastructure. Ireland's historical neutrality and limited defense resources have led to calls for enhanced maritime security and defense investments, including modern surveillance technology and international cooperation. The government's response includes participation in EU security projects and collaboration with neighboring countries on maritime security.

In November 2024, a Russian spy ship, the Yantar, was escorted out of the Irish Sea by the Irish navy after it was found patrolling an area with critical submarine pipelines and cables. The vessel's presence heightened concerns due to its proximity to interconnector cables vital for internet services linking Ireland to the UK, operated by major tech companies such as Google and Microsoft.

Regulatory and Policy Framework:
The protection and maintenance of undersea cables fall under the jurisdiction of national governments, with private companies often responsible for their security. In Ireland, the Department of Communications, Climate Action and Environment oversees the regulation of telecommunications infrastructure, including undersea cables. The Irish Naval Service plays a role in monitoring and protecting maritime infrastructure, including undersea cables. Internationally, the United Nations Convention on the Law of the Sea (UNCLOS) provides a framework for the laying and maintenance of submarine cables, recognizing the "freedom of the seas" and the rights of coastal states.

Conclusion:
Undersea cables are indispensable to Ireland's connectivity and economic infrastructure. Given their strategic importance, ongoing efforts are necessary to ensure their protection and resilience against potential threats. This includes enhancing security measures, international cooperation, and adherence to regulatory frameworks to safeguard these critical assets.