Subsea Cable Under Solent Successfully Replaced

A key milestone to replace one of three subsea cables under the Solent, supplying the Isle of Wight with electricity, has been successfully completed.

The £14 million deep sea bed cable installation project is being delivered by a specialist joint venture between VolkerInfra and VSMC and awarded by Scottish and Southern Energy. It is the first subsea electrical installation under the Solent waterway for 40 years.

With over 5600 meters of the 132 kV (extra high voltage) cable, weighing 600 tonnes now buried under the Solent, the project involves two primary phases. The first phase was completed in November last year, where a 930 metre horizontal directional drill was installed successfully from Thorness Bay in the Isle of Wight out into the seabed of the Solent.

The second phase was completed this June, following the manufacturing of a single length bespoke cable and has now been installed between the Isle of Wight and the coast of Hampshire. This was achieved by using the expertise of VSMC and their specialist divers and marine installation vessels.

Jonathon Humphries, managing director of VolkerInfra, said: “It’s extremely pleasing to see the whole project come together and I’m proud that this joint venture between VolkerInfra and VSMC is on course to deliver on this complex project, on time and within budget.”

With over 5600 meters of the 132 kV (extra high voltage) cable, weighing 600 tonnes ready to be buried under the Solent, Chief Executive of VolkerWessels UK, Alan Robertson, and Managing Director of Networks at Scottish and Southern Energy, Mark Mathison, travelled down for the first stages of the installation in early June. They were impressed with the complexity and engineering involved in such a large project.

Commenting on the overall day, Alan Robertson said:“It was quite incredible to witness the machinery involved in installing this cable under such a busy waterway. It’s not apparent until you actually get to the site how big a feat of engineering this is, and that this collaboration brings together best practice of VolkerInfra and VSMC. All this continues to strengthen the relationship between these two parties.”

Before the residents and businesses of the Isle of Wight benefit from the new undersea cable, the project team must ready themselves for the final phase, which is to connect the new cable to the network in the Isle of Wight and Hampshire followed by carrying out a full testing and commissioning process for project conclusion in September this year.

Press Release, June 25, 2014; Image: VSMC