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Project case study: Super highways subsea cable installation

Updated: Mar 11, 2023

Irish Sea Contractors delivered the intertidal installation of the new subsea high fibre cable systems between Ireland and the UK, and the UK and the Netherlands for euNetworks.


In 2019, Irish Sea Contractors (ISC) was contracted by McMahon Design & Management Ltd. (MDM) to deliver the intertidal works on the installation of the new submarine cable, Super Highway 1, between Ireland and the UK. This project was a strategic investment by the ultimate client euNetworks in building critical internet infrastructure linking Dublin to London and Lowestoft.

In the next stage of the project, euNetworks’ invested in the second Super Highway, linking Lowestoft via a new submarine cable Scylla to Ijmuiden and then onto Amsterdam. This is the first subsea cable system between the UK and the Netherlands since 1999. ISC was contracted by MDM to complete the intertidal works on the second phase, following a successful completion of the Super Highway 1.

Scope of work

The ISC team delivered the following works on this project:

  • Survey of cable routes using an ROV

  • Completed pre-lay grapnel run and route clearance

  • Installation of concrete mattresses on route between the UK and the Netherlands at five crossings

  • Installation of cable protection systems

  • Cable pull-in and lay

  • Burial of cable between 1.5 m – 3 m burial depth (differing per location requirements) using a mix of ISC’s burial tools i.e. Sandpiper LT, Oceanjet 200, ST2

  • Pre-laid, as-laid and as-buried survey

Throughout the project, the team were faced with challenges such as strong currents, poor weather, mobile sandy seabed. The team persevered, drawing on their previous subsea cable experience and marine knowledge to deliver two successful campaigns for our clients.

The result

Both campaigns were successfully delivered. These new fibre systems deliver vital infrastructure to support businesses in Ireland, the UK and Amsterdam, delivering high bandwidth data centre to data centre connectivity between and within cities in Europe.

Super Highway 1 was operational and services delivered to clients by euNetworks in November 2019 and the second Super Highway enabled euNetworks’ to deliver services to their customer in September 2021.

Read euNetwork's case study on Superhighway 1 and Superhighway 2.


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