Mariners are advised that the first cable laying campaign for the Western HVDC Link has been successfully completed in Liverpool Bay. A Notice to Mariners advising of progress, the extent of the cable that has been laid, and the location of buoys and cable mattresses on the cable route can be downloaded here and is summarised below.
Shallow water cable installation
The cable laying vessel Atalanti has successfully completed the installation of the shallow water section of cable. The extent of this cable and the coordinates of the route are given in the Notice to Mariners that can be downloaded here.
Mariners’ attention is drawn to the following items:-
Sub-surface buoy
A sub-surface buoy has been placed at the end of a 100m wire cable that is attached to the end of the power cable. This has been placed to assist cable recovery when cable laying resumes in this area. The buoy is floating 2m above the seabed at the following location:-
- Sub-surface buoy: 53°31.592’N 003°33.628’W
This buoy does not present a hazard to navigation, but is not designed to be over-trawlable.
Temporary concrete mattressing
Post lay survey work on the cable route has been completed. It was found that the expected burial depth was achieved along the route, apart from at four locations involving short stretches of cable. Concrete mattresses have been placed over the cable at these locations. The locations of the concrete mattresses are:-
- Cable KP35.353 – KP35.359 (6m of cable, 1 mattress)
- Lat 53° 31.708’ N Long 003° 33.318’ W to
- Lat 53° 31.706’ N Long 003° 33.323’ W
- Cable KP35.330 – KP35.332 (2m of cable, 1 mattress)
- Lat 53° 31.713’ N Long 003° 33.303’ W to
- Lat 53° 31.715’ N Long 003° 33.298’ W
- Cable KP35.338 – KP35.343 (5m of cable, 1 mattress)
- Lat 53° 31.712’ N Long 003° 33.305’ W to
- Lat 53° 31.710’ N Long 003° 33.309’ W
- Cable KP35.447 – KP35.455 (2 mattresses)
- Lat 53° 31.684’ N Long 003° 33.389’ W to
- Lat 53° 31.680’ N Long 003° 33.397’ W
The concrete mattresses may stand up to 15cm (6″) above the level of the surrounding seabed. They do not present a hazard to navigation in the area. They have not been tested to determine that they are over-trawlable.
The locations of these mattresses are shown in a chart attached to the Notice to Mariners that can be downloaded here.
Trial length of cable on the seabed
A 200m length of cable has been placed on the seabed close to the exclusion zone around the Douglas oil platform. Each cable end is moored by a 100m steel wire terminated with a clump weight. This length of cable will be used to check the operation of equipment before the main installation phases of the project, planned to start in March 2015. This length of cable will be removed when the project is complete.
The location of the cable is between subsea buoys between:-
- Lat 53° 32.659’N Long 03° 36.769’W to
- Lat 53° 32.475’N Long 03° 36.581’W
Mariners are advised that the length of cable will not present any hazard to vessels on passage. It is not designed to be overtrawlable.
The locations of this cable length is shown in a chart attached to the Notice to Mariners that can be downloaded here.
The Western HVDC Link
The Western Link will be an undersea cable linking Ardneil in the Clyde with the Wirral in north-west England. Details of the project can be found on our website here.
Cable laying schedule
Installation of the Western Link cable is due to start in the shallow waters at the southern end of the route in October 2014. The main cable installation campaigns are due to be completed by February 2016.
Further information about the installation schedule and the vessels that will be carrying out this work will be circulated to all interested parties as construction proceeds.
If you have any queries about the Western Link project, please contact Jim Andrews, Fisheries Liaison Officer by e-mail or by phone on +44(0)7908-225865.