From Iceland to Galway: The creation of Ireland’s next subsea cable

As the world becomes more connected than ever before and the number of data centres is on the rise, there is a growing need for subsea cables.

These long cables, which have become a vital network for data travelling around the globe, lie on the ocean floor and send data as pulses of light inside thin strands of wires, or optical fibres, within the cable.

Ireland already has a number of subsea cables in place, and another is due to be operational by 2023.

Iris is a new high-speed subsea cable system that spans approximately 1,700km in length and connects Galway to Iceland. It will be the first direct connection between the two countries.

The cable will be deployed and maintained by Farice, a telecommunications service company owned by the Icelandic government that already runs two other subsea cables from Iceland to Scotland and Denmark.

Selecting the route

Specifically, the Iris cable will run Galway Bay to Thorlakshofn on the south coast of Iceland.

Thorlakshofn was chosen because of its proximity to both Reykjavik and the country’s growing data centre industry, while still being far enough away from other submarine cable landing sites. The cable will connect to a Verne Global data centre in Iceland.

Farice CEO Þorvarður Sveinsson told SiliconRepublic.com that Galway was selected as the entry point to Ireland for a number of reasons.

“Geographically, it is accessible to Iceland, while the local waters are relatively calm, which means it’s a stable and secure option to bring a cable ashore on the Irish coast,” he said.

“The area also has established secure terrestrial connectivity options, linking it to Dublin, which is in turn a major network hub in Europe. Its existing network density made it a very attractive location.”

Sveinsson said the Iris subsea cable will be “the catalyst” for even more network investment in the area. “For example, Finnish company Cinia and US telco Far North Digital are building the Far North Fiber, a subsea cable linking Europe to Japan, avoiding Russian waters. Their plan is to land the cable in Galway,” he said.

“This means that local people and businesses will soon be served by a booming ecosystem of advanced network infrastructures, which could support further growth of digital infrastructure and services in the area, bringing local economic benefits.”

Once the landing sites were selected, a thorough marine survey on the route needed to take place.

“For the Irish part of the route this took place in 2020 and involved the deployment of a specialised vessel with a crew of 30, which conducted sonar scans of the seabed,” said Sveinsson.

“They looked at every part of the seabed to make sure there were no wrecks, artefacts, reefs or other important environmental locations along the route. They also looked for places where there was heightened risk of cuts to the cable – such as where there are lots of boulders or trawlers fishing on the ocean floor.

“We then refined the route to make sure risks to the environment and to the integrity of the cable were minimised. Bear in mind that subsea cables are narrow in diameter, so the mud and silt on the seabed will cover it within just days of being laid. This means the environmental impact is minimal.”

Bringing the cable to life

Sveinsson said the team is on track to go live “at the very start of the new year” with work on both landing sites now complete.

“The Galway shore end work took place in June of this year, with landing and burial of around 10km of the cable from the beach to the sea. We also began laying the subsea cable in May 2022, starting in Thorlakshofn before sailing south,” he said.

“We are on track to reach Galway in August for the final splice of the cable. Once that is complete, we will spend the remainder of the year conducting testing.”

The construction phase, which is now complete, was “very carefully managed” according to Sveinsson in order to avoid disruption to local people and the environment.

“We used a technique called horizontal directional drilling to create an underground route from behind the beach directly to the ocean, thus preserving the beauty and integrity of the beach itself. The whole installation on the beach took just a week and it’s invisible to the naked eye; something that is important both for environmental and security reasons,” he said.

“We worked hand-in-hand with the Irish authorities before and during the build, and were involved in two public consultations in the foreshore licence application. It’s a beautiful part of the world that local people are extremely passionate about. We have been very conscious of our role in preserving it.”

Data centre concerns

While the need for connectivity and networks has become vital, the growing demand for data centres has also sparked intense debate around sustainability, particularly when it comes to energy consumption.

However, Sveinsson said the challenges faced by the Irish data centre industry could be somewhat alleviated by increased connectivity links in and out of the country.

“Rather than keep all their applications in local, metropolitan data centres – an approach which is expensive and won’t scale because of capacity issues – more connectivity options allow Irish organisations to move some of their workloads to facilities elsewhere,” he said.

“High-intensity applications consume a considerable amount of power – something that Iceland, with its 100pc renewable-powered grid, has lots of. The cost of power in Iceland is also considerably lower and more predictable than in Ireland and the rest of Europe, so there are cost advantages to moving some applications there too.”