Factory splicing of deep water power umbilicals – United States

Power CSL Scope 

Factory splicing of medium voltage power cores during manufacture of an ultra-deepwater ESP power umbilical.


An international subsea umbilical company developed a product design for deep water subsea production system utilising high power multiphase boosting pumps. The umbilical design incorporated 3 power triads each comprised of 3 x 95mm2 12/20kV power cores. Due to the long lengths of umbilical to be manufactured the requirement was for 30 triad splices (ie 90 individual power core factory joints). 

Power CSL Deliverables 

  • Development of method for factory jointing of power core triads involving splicing of the laid up power cores and stranded copper drain wire. 
  • Production of trial joints and qualification testing (electrical, mechanical, and hyperbaric) to a demanding end Client specification.
  • Mobilisation of PCSL jointers and factory splicing equipment to umbilical manufacturer’s US facility to provide splicing service over a 3-month period.


The umbilicals were produced on schedule. They have since been installed and have been providing satisfactory performance for some years.  

Power CSL subsequently provided its factory splicing service for a second phase of the oil field development. The same factory splicing concept was selected by the end Client for application in the manufacture of umbilicals for the world’s deepest water subsea production system (2,900 metre water depth).

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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.