CT Offshore set a record by installing 108 cables over 164 days for the West of Duddon Sands offshore wind farm project in 2013. They introduced the use of mini-ROVs to more efficiently prepare the messenger wire for cable pulls, reducing the need for divers. The project scope included installing 11 power cables and 97 inter-array cables using cable plow and trenching vessels. Halfway through the project, the client DONG Energy praised CT Offshore's proactive installation performance and quality of work.

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Case Study
West of Duddon Sands OWF (2013) – 108 cables / 118,000 m
After starting up the project in early June 2013, 164 days later CT Offshore could proudly announce that
a remarkable record in cable laying was set of ‘108 cables in 164 days’, where some days up to 3 cables
per day were installed, both 1st
and 2nd
end pull in and surface laid.
Introduction of Mini ROVs
This was also the project for CT Offshore to introduce the use of Mini ROVs, which significantly reduced
the time taken for preparing the messenger wire safely and efficiently, as the need to reduce divers Is
required.
CLV SIA deck
1. Scope of Work
Installation and burial of 11 PCC cables and 97 ICC cables, using the CPS system Tekmar.
 Cable transport by Freighter of cables in consecutive lengths
 Cable load-out
 Pre-lay Multibeam survey (MBES)
 Pre-lay grapnel run (PLGR)
 Rigging of towers and messenger wire work
 Array cable installation
 Post-lay inspection (PLI)
 Optical time delay reflection (OTDR) test
 Post-lay burial (PLB)
 Post-burial inspection (PLI)
 ROV post-burial survey
Vessels and equipment utilized
Cable Installation: CLV SIA
MBES / TSS Survey: MV LINE / MV SANDER 2
Trenching vessel: MV MAESK RESPONDER / MV VOS SYMPATHY
Trencher ROV: CTO 103
Execution period, surface laid cables
Start-up 5 June 2013
Completed 17 November 2013
“Statement from the client, half-way through project
DONG Energy - Lars Bruun, Installation Manager…
“During the still on-going array cable installation work, we have had
very good co-operation with CT Offshore.
Our WoDS project team is very content with CT Offshores’ cable
installation performance to date. They have been proactive, shown
initiative and professionalism in their performance which is reflected
in the quality of the cable installation work up to now.”

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Raw Installation Time – 108 ICC Cables (West of Duddon Sands)
1.1 Learning curve, 108 cables
2.1 Min. / Average installation time (hrs.) of 108 cables. 2.2. Duration of time vs. number of cables
2.3 Assigned in Project – Overall time consumption, according to DPR report structure

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2.4 Assigned in Project – Overall time consumption (DPR report in further details).
CLV SIA at West of Duddon Sands OWF
Cable transport by Freighter Cables at harbour site Cables being loaded at turntable

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Cables loaded at CLV SIA CLV SIA completing the 2nd end pull
Mini ROVs were introduced as an innovative way of reducing time for messenger wire set up and documentation for the pull ins.