Modification of the Cable Access Tower on HelWin alpha

The Cable Access Tower is a densely packed technical room. New stiffeners and steel components had to be integrated into the existing structure without interfering with cables, conduits, or operational systems.

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The spatial constraints complicated surveying, scaffolding, material handling, welding positions, and corrosion protection. At the same time, high standards for qualifications, inspection, and traceable documentation had to be met.

01 · Surveying the existing site

An offshore site visit was conducted to survey the facility and inspect access routes, installation spaces, cable runs, scaffolding anchor points, container areas, and power supply—directly on-site.

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02 · Detailing the execution

Based on existing data and drawings, the project schedule, surveying, scaffolding, assembly and material handling concepts, as well as welding and inspection planning were developed.

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03 · Preparing steel components

Stiffeners and other components were manufactured, quality-tested, coated, and prepared for secure transport for offshore deployment.

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04 · Enclosing and protecting the workspace

Scaffolding and enclosures created controlled conditions. Existing cables and systems were given special protection during dismantling, hot work, and coating.

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05 · Assembly, welding, and verification

The components were fitted and welded in a coordinated sequence. WPS, weld sequencing, non-destructive testing, coating inspection, and as-built documentation ensured full traceability.

• Very limited workspace inside the Cable Access Tower – many work steps performed between existing steel, cables, and installations.
• Protection of existing cables and systems during steel construction and hot work.
• Close coordination with the client and the inspection authority.
• Integration of scaffolding, surveying, steel construction, welding technology, NDT, and coating.

A complete, execution-oriented project solution was developed and implemented for the CAT conversion: from site survey and engineering to manufacturing, assembly, welding, inspection, and coating services.

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In addition to the main modification, the project documentation also covers subsequent coating and completion scopes – providing seamless verification throughout the entire project period from 2019 to 2023.