Subsea Interconnector Cable Failure




HKA was engaged to provide a review of a joint venture EPC contract for a consortium which was responsible for the design and construction of a high voltage (2.2GW) direct current (HVDC) link between Scotland and England.

We were engaged by the consortium as part of an investigation team to complete a strategic review of the project. Our remit was to focus on the terms and management of the contract, specifically around the installation, commissioning and failure criteria.

The consortium acting as a contractor for the project, were responsible for the design, manufacture, installation and commissioning of the link. This included the converter stations (DC to AC) and cable manufacture and installation, both offshore and onshore.

Faults at the converter station and cables had caused major outages of the link.

What we did

HKA was requested to consider the management of the contract and whether all remedies and options had been considered to the benefit of the client. We provided advice and guidance on the operation of the procedures and entitlements to the client given the cable failures.

We were also asked to consider if any of the key clauses or operation of the contract should be modified or amended for future projects of a similar nature.

We reviewed the:

  • Contract changes including Invitation to Tender v Execution;
  • Contractor’s key obligations;
  • Variations;
  • Contract remedies; and
  • Costs mitigation methods.

We also investigated the cost increase and delay aspects of the project relating to prolongation of the works such as manufacturing issues and offshore cable installation.


HKA provided ongoing advice to the client leadership team and drafted a briefing note advising on the client’s rights and entitlements surrounding the cable failures, including providing advice on the mechanisms in the contract surrounding failure criteria and warranty obligations.

Further, HKA has provided the quantum and delay reports to the legal team in relation to the project delays, and we are currently awaiting the next stage of developments.

Project Details
  • Client
  • Year
  • Value
    ~USD$1 billion
  • Services
    Expert, Engineering and Construction Quantum, Delay and Disruption Analysis
  • Sectors
    Construction and Engineering, Power and Utilities




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