The cable between Skaill Bay in Orkney under the Pentland Firth, and Dunnet Bay in the Scottish mainland, will enable BT to launch its 21st Century Network (21CN) in the Northern Isles. Coming ashore at Banff, the cable will provide connectivity to the Northern Isles alongside existing microwave radio links.

Brendan Dick, director of BT Scotland, said: It’s one of the biggest projects BT has ever undertaken and much more work will have to be done before 21CN comes to Orkney and Shetland. 21CN is for all our customers, whether they’re service providers in their own right, part of a large organisation, a smaller business or a consumer with a BT phone. Everyone will enjoy a better overall experience, from ordering a service to paying the bill.

BT’s 21CN programme creates a single, converged multi-service Internet protocol-based network. The new network in Scotland will replace equipment in more than 1,000 exchanges across the nation. Nearly 60 exchanges in the islands will have existing equipment replaced with 21st Century kit.

BT has signed a deal with Faroese Telecom to share the submarine cable laid between the Faroe Islands, Orkney and Shetland and the Scottish mainland.

Gabriel Ruhan, CEO of Global Marine Systems, said: The new subsea cable, and 21CN in general, will enable BT’s customers to meet demand from their customers for new feature-rich multimedia and multi-play services. We are very pleased to be a part of such a significant project.

Global Marine has already begun the work with its cableship CS Sovereign, which is using its submersible plough and remotely operated vehicle systems to install the cable up to one metre below the seabed. The company expects to complete the work in around three weeks.

Global Marine installed a new cable system connecting the UK with Guernsey in the Channel Islands in May 2008.