Case Study

Developing the Nordic and Baltic energy markets

Case Study Eslink

The Estlink Cable provides vital infrastructure to supply the Nordic electricity market with electricity generated in the Baltics. 

With a wealth of experience in the power and installations market, Global Marine was awarded the contract to install the 154 km of cable. 

ABB, a leader in power and automation technologies needed total peace of mind that the cable installation, a critical element of the project, would be completed to the highest professional standards and as a result chose Global Marine as their partner of choice. 

The ABB cable will ensure a reliable and secure supply of electricity which, in the longer term, will also help enable further energy suppliers to enter the Baltic and Nordic energy markets. 

Project Overview

  • Vessel: C.S. Sovereign
  • Submersible: Super Mohawk and Atlas 
  • Cable length: 154 km 

CS Sovereign

Eslink Case Study

The Project

The first stage of the project for Global Marine began in Scotland where C.S. Sovereign had a pair of cable tanks and loading arms installed to accommodate the size of the Estlink cables. The two 77 km high voltage cables weighing approximately 4,000 tonnes, were then loaded in Sweden where they were then tested during offshore trials prior to sailing for Estonia. 

Stage two involved one end of the cable being oated ashore and connected to the Estonian mainland in Talin. The installation process then truly began in the Baltic Sea and after negotiating the narrow Finnish archipelago, C.S. Sovereign arrived in Finland. 

After successful cable testing the installation phase of the project was complete and the burial commenced. 

The Challenge

The installation involved the bundling and simultaneous lay of the two cables which were held in two separate cable tanks onboard C.S. Sovereign. The mechanised loading arms were used to perfectly synchronise how the cable was fed out of the tanks, through the bundling machine and over the modi ed stern of the vessel. 

The burial depth requirements for the project were quite precise, being not greater than one metre in the main and not greater than 0.6 m in areas where the soils had high thermal conductivity. 

Throughout the project, “touchdown” monitoring, using the underwater inspection ROV Super Mohawk, was used to monitor the touch down position of the cable ensuring the avoidance of sea oor obstacles. 


Ship: C.S. Sovereign, an experienced offshore engineering ship, capable of handling the wide variety of subsea tasks required by such diverse industries as telecommunications, oil and gas, renewable energy and deep sea research. 

Submersibles: Super Mohawk, a light work class vehicle equipped to carry out the tasks associated with light intervention and inspection works in multiple sectors. 

The Atlas is a state of the art, ultra heavy work class ROV designed for intervention, trenching, umbilical and power cable maintenance, and post lay and inspection roles. 

“Global Marine has extensive experience in the power industry, ranging from oil and gas, electricity through to wind farm installations and this knowledge coupled with its innovative technology, made us highly con dent that our mission critical installation was in safe hands.” 
Mr. Arne Abrahamsson 

Oil & Gas Telecoms Offshore Renewables Power Deep Sea Research