MacArtney Provides Subsea Infrastructure Solution at Fehmarnbelt Fixed Link

MacArtney has worked with Femern Link Contractors to deliver an integrated subsea infrastructure solution supporting the placement of tunnel elements at the Fehmarnbelt Fixed Link between Denmark and Germany. The tunnel spans approximately 18 kilometres at depths of up to 40 metres, with three of its 89 elements now successfully immersed and connected. The infrastructure supplies power and connectivity to support the controlled positioning, monitoring and control of the massive tunnel elements during immersion.

 

Details of the Project

 

MacArtney has supported a major infrastructure project. It worked with Femern Link Contractors. Together they delivered a subsea infrastructure solution. This supports the Fehmarnbelt Fixed Link. The link connects Denmark and Germany.

The infrastructure serves a specific function. It supports the controlled positioning of tunnel elements. These elements are placed on the seabed. The solution enables precise immersion operations. This is central to the tunnel's construction.

 

The Scale of the Tunnel

 

The tunnel is a substantial engineering undertaking. It spans approximately 18 kilometres in length. It is laid at depths of up to 40 metres. This places it well below the sea surface. The scale makes it a landmark project.

Construction is progressing steadily. Three of the 89 tunnel elements have been immersed. These have also been successfully connected. This marks early progress on the tunnel. Construction continues on the remaining elements.

 

The Immersion Process

 

Each immersion is a complex operation. Standard elements measure 217 metres in length. They are 42 metres in width. Each weighs approximately 73,500 tonnes. This makes each immersion a major undertaking.

The process involves several careful steps. Each element is floated out of the work harbour. It is then towed offshore to the site. There it is lowered into a seabed trench. Finally it is guided into its final position.

 

Read More: Master Boat Builders Launches Third Escort Tug for Maritime Partners

 

MacArtney's Contribution

 

MacArtney refined the system design. It built on an initial concept from the contractors. It helped through iterative engineering. This adapted as installation methods evolved. Operational requirements also shaped the design.

The company's Danish base supported this work. Design and testing were based in Denmark. Project management and on-site support followed. Frequent interaction shaped the system. Prototype validation and optimisation informed the final configuration.

 

The Infrastructure Components

 

The solution comprises several key elements. Power and connectivity infrastructure spans the tunnel elements. It also covers the modular Immersion Pontoons. This supports positioning during immersion. Monitoring and control are also enabled.

Specific equipment supports the connection process. Retrieval Frames connect to pre-installed connector plates. These carry cameras, lighting and actuators. They enable monitoring during connection sequences. They supply power and data to pumps and sensors.

 

The Broader System

 

A wider infrastructure underpins the solution. Umbilicals contain power and data cables. These include Ethernet and coax cables. Integrated connectivity enables transmission between systems. This links topside systems and tunnel elements.

Further components complete the system. Control units handle power distribution and data. Stress terminations and mounting frames feature. Multiplexers and junction boxes are also included. These are installed on elements and pontoons. Once positioning is complete, an ROV recovers the Retrieval Frames.