Remedial works on a 2000 MW High Voltage Direct Current (HVDC) interconnector running between the South coast of England and the North coast of France : IFA2000

Description

IFA2000 is a 2000 MW High Voltage Direct Current (HVDC) interconnector running between the South coast of England and the North coast of France. It is made of four (4) pairs of cables buried in four individual trenches. Recently, a subsea MBES and SSS survey has been performed alongside the cable route and has shown two freespans on one RTE cable of one cable’s pair. These freespans are less than 10m long and have been detected on English side closed to Folkestone landfall with very shallow side depth conditions. Due to potential instability, vibration and fatigue which could lead to damages to the cables, the scope of work of the contractor is to perform all necessary remedial actions to stabilize these freespans and protect the cable by the most adequate means and to provide an updated survey of the modified area. Lot 1: Context RTE, as French Transmission System Operator, is maintaining, operating and developing the power transmission system. As central component of the electricity system, RTE supports the energy transition by leveraging the diversity of the energy package on a local, national and European scale. Since the late 1980’s, RTE and National Grid are operating the IFA2000 interconnector, between France and England. IFA2000 is a 2000 MW High Voltage Direct Current (HVDC) interconnector running between the South coast of England and the North coast of France. It is made of four (4) pairs of cables buried in four individual trenches. Scope of work Recently, a subsea MBES and SSS survey has been performed alongside the cable route and has shown two freespans on one RTE cable of one cable’s pair. These freespans are less than 10m long and have been detected on English side closed to Folkestone landfall with very shallow water depth conditions. Due to potential instability, vibration and fatigue which could lead to damages to the cables, the scope of work of the contractor is to perform all necessary remedial actions to stabilize these freespans and protect the cable by the most adequate means and to provide an updated survey of the modified area. Therefore, to summarize, the Contractor’s scope of work includes but is not limited to: • Preparedness, including procedures, associated engineering and project management. • Performance of cable freespans stabilization and cable system external protection. • Performance of the remedial works as-built survey and associated reports. • Management of interfaces with the relevant stakeholders.