Subsea cable-laying plough lost on seabed

Subsea cable-laying plough lost on seabed 16/9/14

An essential piece of equipment lost on the bottom of the sea risks hampering a multi-million pound installation of fibre superfast broadband to the Western Isles.

A large eight-tonne metal plough from the cable-laying ship MV René Descartes got stuck on the seabed, 100 metres down, as it was digging a trench through heavy mud to bury miles of expensive fibre optic cable.

It appeared to jam on something hard and its strong towline broke during attempts to pull it free as the underwater wires were being buried to the east of North Uist on Monday.

No spare plough is onboard the ship forcing ship-owners Orange Marine to look at getting a replacement shipped in from Norway.

Orange Marine is part of the Orange mobile phone company, formerly France Télécom.

Experts are on scene trying to figure out if they can recover the sunken equipment which is located in the Minch, at the eastern entrance to the Sound of Harris midway between North Uist and Harris, about 2.5 miles north east of Uist.

At this stage, there is no way of knowing how damaged it is.

A navigation warning was broadcast on Sunday afternoon saying: “Cable plough marked by yellow cable buoy with flashlights, wrecked on seabed.”

A plough is needed to bury the cable in high traffic relatively sea areas where fishing trawls and anchoring ships could otherwise sever it.

A stop-gap is to use small remotely operated underwater submarine vehicles.

However, a sea plough is necessary to continue the cable laying operations across the north of Scotland before the weather breaks and is the whole point of the expensive chartering of a specialist ship.

The Carnan to Dunvegan on the Isle of Skye has still to be completed and more burial is required on the Lochboisdale to Eriskay seabed.

Other cablelaying is needed for other islands off Scotland.

The MV René Descartes is presently anchored at Lochmaddy awaiting instructions.

The maritime authorities have been notified of the danger and navigational warnings are being broadcast to seafarers.

The cable laying is part of a north of Scotland-wide £146 million fibre broadband scheme led by economic development agency, Highlands and Islands Enterprise (HIE).

A HIE spokesperson said: “The plough became stuck in very soft seabed sediments while laying the inter-island Harris to Uist cable, and during attempts to recover it the tow wire broke.

“We are waiting for a formal plan from Orange Marine as to what is going to be done to recover the plough which is marked with a buoy.

“The master of the Rene Descartes has given location details to Marine Scotland, the Maritime and Coastguard Agency, the Northern Lighthouse Board and Stornoway Coastguard.

“The subsea work has continued, with the cable being laid out on the seabed and being buried by one of the remotely operated underwater vehicles.”

The plough broke-off during an operation to link the future backbone internet communication network for the Western Isles.

One end of the fibre optic cable was landed ashore at Strond, in South Harris on Friday where it will run northwards into Lewis.