Repairs to Broken Subsea Broadband Cable for Tiree Island Set to Begin

Good news for residents and businesses on the tiny, remote Inner Hebrides Island of Tiree, which suffered a break in its only subsea fibre cable after Storm Amy struck Scotland at the start of October – resulting in disruption to local broadband and phone services (here). Cable repairs are finally about to get underway.

Tiree is a low-lying island that is home to a population of around 700. The island’s subsea fibre cable, which runs between the village of Scarinish on Tiree and Calgary on Mull (pictured – see red arrow), was first deployed all the way back in 2014 as part of the Digital Scotland contract with BT (i.e. the BT Highlands and Islands Submarine Cable System).

However, since the incident some 6 weeks ago, the island community has been left to depend on a slow and capacity strained temporary satellite broadband link for backhaul via Starlink – provided by BT. Earlier reports also suggested that the cable may not be repaired until December, which is quite a long period of time for a community to be without its main link.

The damaged subsea cable rests in shallow water about 600 metres offshore (such cables are more exposed to damage during particularly violent storms), which appeared to require both a barge and a period of calm weather for the repairs to take place.

Progress is being made

The latest update from the local community is that a cable repair ship has now been dispatched and is due to arrive by the end of this week. At the same time, the shore team are due to start work on land tomorrow. “The cable work is expected to take up to 10 days. It may take slightly longer for the work at the exchange to be completed, but we will keep you updated on progress,” said the Tiree Development Trust.

In terms of the work itself, BT confirmed that the cable repair engineers plan to replace the entire section from the break to the shore landing (similar to what happened in Shetland last month). But the work will also aim to protect around 1.2km of cable in a particularly exposed area with additional armouring to limit the chances of future damage.

BT noted that the cable itself is designed to last for 25 years, although they noted that most such subsea cables often last well beyond that age. The cable has already been installed for 11 years and has so far only suffered 2 faults during this time.

Naturally, the repairs will require around 4-5 days of calm weather (i.e. relatively low wind speeds and sea swell), which could be a challenge given the variable forecast over the next 1-2 weeks. Suffice to say that delays remain a strong possibility.

In the meantime, the local community, alongside representatives from Shetland, have held discussions with the Scottish Government over the need for greater digital resilience and back up plans in the event of a future break. Economically speaking, this could be challenging for a smaller community like Tiree, although those involved said they felt encouraged by how seriously the government took their concerns.