Offshore Array Cable Replacement - Burbo Bank Windfarm

Ventus Energy delivered a full offshore array cable replacement programme for N-Sea at Burbo Bank Windfarm, providing integrated project management, diagnostics, recovery, pull-in, termination, testing and as-built documentation support.

Project overview

Client: N-Sea
Services: End-to-end full cable replacement programme
Location: Liverpool Bay, west coast of the UK
Project lead
Client contact: James Sutton, Project Manager
Duration: 64 days
Completed: February 2026

The brief

Following the failure of an array cable at an offshore wind farm, Ventus Energy was engaged to deliver a full cable replacement programme - encompassing pull-in, termination and testing across two wind turbine generator (WTG) locations.

The project demanded a technically precise, highly coordinated response, with pre-installation testing carried out at the cable supplier’s load-out facility in Velsen-Noord, Netherlands, before offshore operations commenced.

Ventus’s scope of work included:

Project management and engineering
Supply of all related project documentation
Post cable load-out testing at the cable supplier’s facility (OTDR, TDR, IR)
Array cable LIRA testing on both failed and non-failed cable prior to works commencing
Testing of the failed array cable during cut and recovery to pinpoint the fault location
Array cable recovery and pull-in at two WTG locations
Cable termination at two WTG locations
Cable testing between the two WTG locations
Production of full as-built documentation

Challenges

The project presented a number of significant obstacles that required rapid problem-solving and seamless cross-team coordination to protect the programme timeline, including:

Releasing the failed array cable from the existing cable protection system (CPS), requiring Ventus Tower Teams to work in direct support of the cable recovery vessel and coordinate additional ROV support
A last-minute change to the CTV sail location at the point T&T activities were due to begin, managed overnight by the Ventus team without delay to works
Full demobilisation and redeployment of equipment back to the original sail site to complete transport to HQ

Solution

With the challenges requiring a flexible and coordinated response, Ventus adapted its approach throughout, including:

Deploying integrated Tower Teams and T&T specialists to work as a single unit across the full scope
Adopting a diagnostics-led approach using LIRA, OTDR, TDR and IR testing from load-out through to offshore installation
Utilising precise fault localisation during cable cut and recovery to minimise time offshore and reduce operational risk
Maintaining a collective team effort to manage the overnight CTV transition and subsequent demobilisation without programme impact

Outcome

The project was delivered safely, professionally and to a high technical standard. All aspects of Ventus’s scope were completed successfully, including the replacement, testing and reinstatement of the HV cables and the splicing of new fibre optic communications cables.

Re-energisation was achieved with minimal issues, a direct result of the thorough testing regime and the team’s technical rigour throughout. The client received a complete set of as-built documentation, providing a clear and verifiable record of the works delivered.

“This was a complex and evolving programme that called for disciplined coordination and the ability to respond decisively to challenges as they emerged. What it demonstrated most clearly was the Ventus’ specialist capability brought together through a flexible, integrated team approach, with every discipline aligned to deliver efficiently offshore. Projects like this are important because they demonstrate what Ventus deliver, but also the trusted capability Ventus brings to offshore wind projects.”

Lee Glendening

Managing Director

“From the handful of days I worked alongside Ventus, I witnessed the termination, testing and installation of the new cable - they demonstrated a strong level of technical competency throughout. The team showed a clear understanding of testing requirements in accordance with the inspection and testing plan. Overall, the contractor delivered the works safely, professionally, and to a high technical standard. No improvements to be offered.”

James Sutton

Project Manager

Benefits

Specialist diagnostics expertise - LIRA, OTDR, TDR and IR testing capabilities deployed from load-out through to offshore installation
Integrated tower team and T&T delivery - we provided one team, one point of accountability across the full scope
Rapid problem-solving - CPS recovery challenge resolved without programme delay through coordinated ROV and Tower Team support
Operational agility - overnight CTV relocation managed seamlessly, protecting the T&T programme
Zero QHSE incidents - strong communication, housekeeping and safety performance throughout
Full documentation package - comprehensive as-built records supporting long-term asset management