Y-shaped joint for EHV submarine cable

Enabling a connection between three XLPE submarine cables


In the present solution the dielectric design leverages the Premolded Joint (PMJ) principle that already exists in extruded cables. The insulation system is composed of a branch insulated electrode and three PMJs.

The electrical contact between the cable conductors and the branch electrode is ensured via soldering or a compression ferrule. Spare place up to PMJ’s inner diameter is filled with conductive material, typically an electrode, assembled from two halves. A PMJ which was inserted and momentary parked is positioned on each electrode to ensure the continuity of the insulation systems.

In order to keep the cable completely watertight, a lead sleeve covers each core joint. The sleeve comes as a lead sheet, which is draped around the core joints, and soldered longitudinally. The sleeves are plumbed to the lead sheaths of the cable cores and branch electrode. The branch electrode water barrier is assembled by soldering two lead shells longitudinally.

The whole assembly is housed in a rigid outer casing for mechanical and corrosion protection. The armour is classically terminated to the outer casing using armouring clamping blocks. The outer casing is then filled with bitumen for corrosion protection.



Concept validated in multi-physic analysis


  • Fast jointing procedure
  • Longterm and reliable dielectric jointing


  • Muti-terminal HVDC grids
  • Submarine cable
  • Extruded insulation


  • Patent FR-16 59962
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