Home > Blog > Subsea Cable Protection Systems – Disconnection & Removal | Part 3 of 5

Subsea Cable Protection Systems – Disconnection & Removal | Part 3 of 5

Published 16 Sep 2019

Subsea Cable Protection Systems

♦ Republished by Chris Dodds 

with Kind Permission of Greg Campbell-Smith ((Director Sales and Business Development at First Subsea)

Subsea Cables

 

 

First Subsea is the world’s leading developer of subsea connection technology, supplying, installing and decommissioning.

Subsea power cables on offshore wind farms are typically protected by means of burial.

This is a well proven means of cable protection used in other offshore industries.

However, at either end of offshore wind array cables they transition from burial, up through the water and into the wind turbine foundation. This free spanning section of cable is susceptible to what can be substantial wave and current loads.

These loads introduce movement and bending into the subsea cable which, without cable protection, can lead to over-bending, over-tensioning, fatigue and abrasion damage.

This exposed subsea cable is traditionally ‘protected’ by means of a relatively expensive and complex proprietary Cable Protection System (CPS).

Our 3rd Article on Cable Protection Systems looks at how subsea cables can be disconnected and removed, focusing on removal times and costs.

Disconnection of the CPS is not a regular occurrence offshore, after a successful installation there should be little reason to disconnect unless the system has experienced accidental damage, premature failure due to design, manufacture or higher than expected loading.

Problems during installation may require disconnection, such as, pinch points in I-Tube, winch capacity exceeded due to friction losses, incorrectly sized pull-in accessories and obstructions in entry holes.

A common misconception is the CPS is removed if the cable is faulty. Typically, the cable is disconnected and passed back through the system and the new cable is threaded back.

First Subsea CPS is a proven removable system. In a recent project an installation issue occurred that required the CPS to be removed. The disconnection process, remedial work and re-connection took less than 12 hours.

Quite some time you may think, but when you consider alternative systems require removal by subsea sawing or risk damaging the structure when removing. First Subsea CPS will save minimum €40,000 vessel, diving/ROV time. Client “it was an invaluable feature that got us out of a bind”

 

➡ If you would like a copy of the report, please contact Chris Dodds [email protected] 

 

LV, MV & HV CABLE JOINTING, EARTHING, SUBSTATION & ELECTRICAL EQPT

Thorne & Derrick are Specialist Distributors to the UK and international Offshore Wind & Renewable industry to provide safe and reliable LV HV Electrical Cable & Power Distribution Systems – we are highly customer responsive and absolutely committed to providing a world-class service.

We have an International Distribution Agreement with Nexans Power Accessories UK to supply their Heat Shrink and Cold Applied ranges of 11kV/33kV/66kV joints and terminations and Euromold brand of separable connectors.

Since 1985, we have established an international reputation based on Service, Integrity and Trust – contact us.

t: 0191 410 4292 | e: [email protected] | www.powerandcables.com

We provide expert technical support and supply from a multi-million pound stock holding:

  • Cable Joints, Terminations & Connectors Earthing & Lightning Protection
  • Cable Accessories – Lugs, Glands
  • Circuit Protection & Fuses
  • Cable Cleats & Clamps Electrical Safety Equipment
  • Cable Pulling & Laying Equipment
  • Arc Flash Protection & Clothing
  • Cable Duct Seals & Transit Systems Surge Arresters & Bushings

Further Reading: