Cutting Inspection Costs and Risk: How the AXIST Offshore Rover Redefines Monopile Flange Measurement

In the world of offshore wind, precision is non-negotiable. Even the smallest deviation can lead to deformation, reduced performance, and costly corrective interventions. Measuring the flange of a mono-pile immediately after piling is one of the most critical moments in the entire installation process. Until now, it required long execution times, highly specialized personnel, the use of a second vessel, and—most significantly—the construction and removal of temporary platforms for every single mono-pile.

AXIST has developed a solution that radically changes this scenario: an autonomous metrological Rover designed specifically for offshore conditions, capable of completing a flange inspection in just thirty to forty minutes.

Performing metrological measurements in offshore environments has always been both a technical and logistical challenge. After piling mono-piles remain at sea with no platforms or safe access for operators. Environmental conditions are unpredictable, and the high costs of installation vessels demand extremely rapid interventions.

Until recently, verifying flange quality after piling required building an internal access platform, installing it, sending specialized personnel to perform the measurements, and then dismantling it. This costly and slow process forced the installation vessel to remain on standby for the entire duration of the inspection.

Prometeo—the Rover developed by AXIST—was created precisely to eliminate this complexity. Transported aboard the installation vessel, it is placed on the mono-pile flange using the crane immediately after the removal of the hammer. From that moment onward, the entire inspection is carried out automatically, remotely, and safely.

The core of this innovation lies in its laser-based measurement technology and complete operational autonomy. Once positioned on the flange, the Rover performs a high-precision 3D scan, measuring flatness, local run-out, tilt, and overall inclination with sub-millimetric accuracy.

The system requires no external references—which would be unreliable on a moving vessel—and does not rely on adhesive targets or prior surface preparation as required by photogrammetry. Prometeo measures the actual flange surface, including areas affected by hammering, delivering a fast, precise, and comprehensive digital report.

To ensure measurement reliability, the device integrates a blower to remove water and debris, a camera to visually document any damage, and a fiberglass cover that protects it from light rain and sea spray. The entire system is remotely controlled via an intuitive interface, accessible even to operators without specialized metrology expertise.

Prometeo is the result of a development process conducted entirely by AXIST and ALTO. Its first real-world application took place on the OceanWind – Moray West project, in collaboration with the installer DEME, which provided valuable operational feedback.

The initial prototype was tested in the United Arab Emirates on a mock-up supplied by Lamprell, under the joint supervision of AXIST, ALTO, and Moray West teams. These tests made it possible to optimize the design and validate the system before offshore deployment. Today, the Rover is patented having algorithms, firmware, and mechanical architecture developed in-house.

The introduction of the Rover has produced immediate measurable benefits. Inspection costs have been drastically reduced: there is no longer a need to build and install temporary platforms, and the vessel no longer needs a dedicated vessel. The entire operation is carried out using a single vessel—the same one that installed the mono-pile—resulting in lower CO₂ emissions associated with additional vessel mobilization.

From an operational standpoint, personnel safety has significantly improved: operators remain on board and control the system remotely, with no need for physical access to the mono-pile. Moreover, the speed of execution makes it possible to inspect 100% of the flanges, providing engineers with immediate data for any corrective actions.

AXIST’s offshore Rover is not merely a measurement device—it is a technological platform designed to evolve. It can already be configured for flanges of different sizes and for variable sampling densities, and it can operate continuously, 24 hours a day, with short charging intervals.

Future developments include adaptations for onshore, naval, and industrial environments, as well as rental and licensing options for installers and inspection companies. Its ease of use and rapid reporting make it an ideal tool for any geometric control activity in challenging settings.

With this project, AXIST and ALTO have opened a new chapter in offshore metrological measurement. Prometeo enables the assessment of mono-pile flange quality with precision, speed, and safety—eliminating the inefficiencies of traditional methods and giving installers immediate, comprehensive control over installation quality.

An innovation that not only reduces costs and operational time, but also represents a concrete step toward a more sustainable, efficient, and technologically advanced offshore industry.

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