Subsea Cable Protection Systems Design For Installation | Part 5 of 5

Published 17 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 5th Article on Subsea Cable Protection Systems looks at design for installation of subsea cables.

It has been documented by insurance companies and underwriters, such as Allianz and GCube Insurance Services, Inc that “subsea cables cause about 70-80% of losses in terms of overall claims amount incurred.”

These claims have included, freak incidents during transportation, manufacturing faults and damage caused by anchors and construction vessels.

In a paper published by Offshore Renewable Energy Catapult last September, a total of 43 array cable and export failures had been reported since 2007, with manufacturing and installation cited to be the most common cause of cable failure in subsea installations.

CPS design should not only consider protection of the cable during the lifespan of the OWF but it should also provide protection during installation, ensuring handling methodologies offshore do not stress the cable or exceed the cable MBR which can lead to premature failure.

First Subsea have addressed these issues by performing a series of special testing programs using their Tensile Bend Test rig, which simulates the installation loads seen offshore, including the function of the quadrant used in second end pull in. The photo below shows the offshore scenario and the onshore simulated test.

 

➡ If you would like a copy of the report, please contact Chris Dodds cdodds@thorneandderrick.co.uk 

Subsea Cable Protection Systems Design For Installation

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: uksales@thorneandderrick.co.uk | 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
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  • Cable Pulling & Laying Equipment
  • Arc Flash Protection & Clothing
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Further Reading: