Gas platform topside replacement project – North Sea

Power CSL Scope 

Design, supply and installation of I-tube mounted hang-offs / protection caps, which are later to be converted into transition joints.


A major oil & gas operator is carrying out a topside replacement programme due to seabed subsidence. As part of the project there was a need for subsea cable hang-offs and protection caps to be fitted part way up the existing J-tube. This was to allow removal of the topside structure in advance of replacement planned for the following year. At a later stage PCSL convert the hang-offs to vertical joints to allow extension of the existing subsea cable to the new platform topside structure. PCSL will also provide zone rated power and optical junction boxes for termination of the subsea cable. 

Power CSL Deliverables 

  • Detailed design study of the mid J-tube hang offs, vertical joints and topside cable accessories.
  • Manufacture and supply of the mid J-tube hang-offs and protection caps
  • Manufacture and supply of the vertical hang-off mounted subsea power cable joints
  • Supply of topside cable accessories
  • Installation of the vertical joints and topside accessories at a later stage


The hang-offs and protection caps were supplied to agreed schedule, with no problems encountered throughout the installation exercise.

PCSL will supply the balance of accessories during 2021, with installation during 2021/22.

< Back to Case Studies

Products & Services

Power CSL provides a complete range of subsea cable and umbilical products and services – from factory jointing (splicing) of medium and high voltage power cores to thoroughly engineered and tested cable accessories including offshore repair joints.


Power CSL’s facilities at its headquarters in Kent, UK, includes impressively equipped cable jointing workshops, a dedicated high voltage laboratory and a wide range of analytical, mechanical, and hyperbaric test capabilities.