[Update – the work described below has now been completed. This notice remains as part of the historical record of notices issued for this project. Please refer to the most recent notice for an up-to-date record of the notices presently in force for this project. This can be accessed via the project description page here.]
Mariners are advised that marine operations for the construction of the Western HVDC Link cable are due to commence in June 2015. Two Notices to Mariners advising about the nature of operations and the proposed timetable have been issued: one for the deep water cable installation in Liverpool Bay (here); and the other for the installation of concrete mattresses along the proposed cable route (here). The proposed activities are summarised below.
Deep Water Cable Installation
The first deep water cable installation campaign is due to start at the beginning of June 2015. This work will commence approximately 37km from the Wirral end of the cable and continue towards the Isle of Man for about 120km. A notice to mariners about this work can be downloaded here and is summarised below.
Installation work will be carried out by the cable laying vessel Giulio Verne, accompanied by the vessel Go Pegasus. The Go Pegasus will follow the Giulio Verne at a distance of approximately 500m, and will tow a cable burial plough, providing for simultaneous burial.
Two separate cables are due to be installed, and will be laid approximately 30m apart from one another. Each cable will be laid separately. The cables will each be simultaneously buried along their entire length, except where the cables cross existing cables or pipelines. At these crossings, guard vessels shall monitor the cable until appropriate post-lay protection (with concrete mattresses or rock placement) can be installed. The cable crossing locations are:-
- Hibernia Cable: 53°45.058’N 003° 48.853’W
- Sirius South Cable: 53° 43.574’N 003°48.733’W
- ESAT2 Cable: 53° 42.492’N 003° 48.646’W
- PL1030 Pipeline: 53° 31.491’N 003° 34.852’W
- PL1032/1033 Pipeline: 53° 31.490’N 003° 34.840’W
(Note: all positions referenced to WGS84 datum).
Prior to cable laying, the vessel Go Pegasus will conduct a pre-lay survey and conduct a Pre-Lay Grapnel Run along the cable routes. Giulio Verne will also recover one of the two cable installed as part of the shallow water cable installation last year and make a joint between this cable and the one aboard the vessel.
Please note that installation dates are approximate and could be affected by project progress and weather conditions.
Concrete mattressing campaign
Mariners are advised that prior to the Western Link HVDC cable installation activities there is a requirement to install mattresses at 8 locations along the cable route. These mattresses will be installed between the 1st-10th June 2015. They are being installed to protect existing submarine cables and pipelines. A notice to mariners about this work can be downloaded here and is summarised below.
Prior to the mattress installation campaign, the Surf Ranger will carry out a pre-installation survey at each location to confirm the position of each cable and pipeline using a detection and tracking system mounted on an ROV.
Mattresses will be placed on the seabed from the vessel Surf Ranger using a frame operated by a ROV. The ROV will carry out a post-installation survey to ensure that the mattresses have been deployed correctly. Once this is confirmed, the vessel will move on to install mattresses at the next location.
The location of mattress locations and the number that will be deployed at each crossing are set out in the Notice to Mariners and are summarised below:-
- Scotland – N. Ireland 2 cable: 54° 56.083’N 005° 32.823’W
- Moyle Interconnector North cable: 54° 55.779’N 005° 32.545’W
- Scotland – N. Ireland Pipeline: 54° 54.913’N 005° 31.714’W
- LANIS 3 cable: 54° 53.814’N 005° 30.664’W
- Scotland – N. Ireland 1 cable: 54° 41.405’N 005° 18.647’W
- Manx – N. Ireland cable: 54° 16.299’N 005° 10.394’W
- ESAT2 Cable: 53° 42.492’N 003° 48.646’W
- PL1030 Pipeline: 53° 31.491’N 003° 34.852’W
- PL1032/1033 Pipeline: 53° 31.490’N 003° 34.840’W
(Note: all positions referenced to WGS84 datum).
Please note that installation dates are approximate and could be affected by project progress and weather conditions.
Vessel details
Details of the vessels involved in these operations, along with their present location can be found on MarineTraffic.com via the links below:-
- Giulio Verne: Cable layer | Call sign IBPU
- Go Pegasus: Tug / supply vessel | Call sign V7CE4
- Surf Ranger: Multi purpose offshore vessel | Call sign V7FU2
Vessels will be monitoring VHF Channel 16 throughout the operation.
The vessels involved in this work will be restricted in their ability to manoeuvre and other vessels are reminded to navigate with caution in their vicinity and pay strict attention to instructions issued to them by navigation authorities.
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.