New access tower fixation on the DanTysk OAP

The access tower, along with the boat landing and platform access, forms a safety-critical interface for CTV operations. Following Storm Herwart, a slight twisting of the access tower was detected; the rubber cone fenders of the horizontal fixation showed signs of deformation and surface cracking, and could no longer ensure a permanent and reliable connection.

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A root cause analysis pointed to inaccuracies in the original design. The goal was therefore not only to replace the damaged parts but to implement a structurally stiffer solution that prevents further relative movement between the access tower and the platform structure.

01 · Transforming the cause of damage into a structural solution

The existing horizontal fixation was evaluated and replaced with a rigid steel connection. Gusset plates and stiffeners distribute the forces into the existing structure.

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02 · Prefabricating components with quality assurance

Steel cones, gusset plates, and stiffeners were prefabricated, quality-tested, coated, and prepared for offshore installation.

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03 · Creating controlled working conditions

Scaffolding, containment, and rope access provided entry to hard-to-reach areas and protected welding and coating work from the elements.

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04 · Remove fenders and install steel fixation

The deformed rubber elements were removed and the connection areas prepared. New steel cones, gusset plates, and stiffeners were fitted and welded in a defined sequence.

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05 · Quality inspection and restoration of corrosion protection

The welded joints underwent non-destructive testing. This was followed by local coating work in accordance with offshore category C5-M High and the preparation of as-built documentation.

• Urgent implementation in spring 2020.
• Work on the central CTV access interface of an operational platform.
• Local reinforcement of an existing offshore structure using complex welding sequences.
• High corrosion protection requirements (C5-M High) and quality control by IWE/FROSIO L3.

The horizontal fixation of the access tower was modified in accordance with the approved design documents; the acceptance report confirms the successful completion of the work.

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Remaining tasks included local coating touch-ups in scaffolding, containment, and contact areas, as well as a subsequent coating campaign inside the boat landing.