picture of a ship connected to an offshore wind turbine with a gangway

Motion Compensated Gangways

Accurate measurements of all 6 degrees of freedom are essential for the automatic motion control of gangways.

illustration of our MRU Marine showing roll, pitch, yaw, surge, sway and heave

Motion Reference Units for Motion Compensated Gangways

The NORSUB Marine MRU offers reliable measurements of roll, pitch, yaw, surge, sway, and heave at the end of the gangway, enabling precise motion control.

In the case of Active Heave Compensation (AHC), obtaining accurate heave measurements in real sea conditions is of utmost importance. However, reliable measurements of surge and sway motions are also crucial. The Marine MRU features a special mode designed specifically for gangway and other Dynamic Positioning (DP) applications where precise measurement of wave frequency motion in surge and sway is required. This dedicated mode ensures optimal performance for gangway control, delivering accurate and reliable motion data.

The Marine MRU provides comprehensive information on positions, velocities, and accelerations for all 6 degrees of freedom at designated remote monitoring points, such as the tip of the gangway. These data can be accessed in NMEA or binary format using the custom protocol generator or by reading the Modbus TCP or Ethernet/IP registers, providing flexibility and ease of integration with existing systems.

Why accurate MRU data is critical for Motion Compensated Gangways

In motion compensated gangway systems, the performance of the Motion Reference Unit directly affects compensation accuracy, gangway stability, and operational safety. In real offshore conditions, vessel motions are irregular, coupled, and often combined with significant horizontal accelerations, conditions where low-quality motion sensors can introduce instability, delayed compensation, increased residual gangway motion, and reduced operational performance.

Accurate motion measurements in real sea conditions

Many motion sensors perform well in laboratory sine-wave testing but struggle in irregular offshore sea states. Norwegian Subsea MRUs are validated in real coupled vessel motions and maintain stable heave, surge, sway, roll, and pitch measurements during complex wave conditions and horizontal accelerations.

This provides reliable motion data for precise gangway compensation and safe personnel transfer operations in challenging offshore environments.

Proven technology with long offshore track record

Norwegian Subsea MRUs have been used in 3D motion compensated and AHC systems for more than 10 years, serving 20+ OEMs and system integrators worldwide. Our sensors are used in motion compensated gangways, offshore cranes, winches, and LARS systems where stable and accurate motion measurements are critical for safe and precise offshore operations.

Easy integration into existing Gangway Control Systems

The MRUs support a wide range of marine industry protocols including Modbus TCP, Ethernet/IP, Modbus RTU, TSS1, SMCC, custom NMEA, and binary protocols, simplifying integration into PLCs, gangway control systems, and offshore motion compensation systems.

picture of an motion compensated gangway

Motion Reference Units designed for Motion Compensated Gangways

Norwegian Subsea produces industry-leading Motion Reference Units (MRUs) for marine and subsea applications. Our MRUs are robust and affordable, and offer high-accuracy performance, along with a plug-and-play interface.

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What our customers say

"They are rock solid. Many Norwegian Subsea MRUs have been running 24/7 inside Miros products for up to eight years without issue, producing real-time data every second."

Jonas Røstad, Chief Commercial Officer, Miros

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"Other MRUs often fail in extreme climates, such as freezing Arctic waters or the intense heat below a metal deck in the tropics and Middle east... Norwegian Subsea MRUs remain stable and functional across its environmental range."

Johnny Rabben, CEO, ShoreConnection

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Next week, the maritime world gathers in Rotterdam for Europort 2025, one of the largest international meeting points for shipbuilders, technology providers and operators. With a strong focus on innovation and sustainability, the exhibition is an important platform for discussing how the industry can meet future demands through smarter, greener solutions.

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A year in Motion Reference Units...

From bathymetric surveys to subsea inspections and wave radar systems, our Motion Reference Units (MRUs) have been put to work in a wide range of challenging environments during 2025. As the year draws to a close we take a quick look back at some of the highlights, applications, and collaborations that helped shape another strong year of progress for Norwegian Subsea.

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Motion Compensated Gangways

Motion Compensated Gangways

Motion Reference Units for Motion Compensated Gangways

Why accurate MRU data is critical for Motion Compensated Gangways

Accurate motion measurements in real sea conditions

Proven technology with long offshore track record

Easy integration into existing Gangway Control Systems

Motion Reference Units designed for Motion Compensated Gangways

What our customers say

Related customers

Related products

Usage area

Connectors

Roll & Pitch accuracy

Heave accuracy

Usage area

Connectors

Roll & Pitch accuracy

Heave accuracy

Related questions

What is the role of motion monitoring in offshore operations?

What is a Motion Reference Unit?

What is a Roll and Pitch Sensor?

Further reading

Advanced motion compensation for sonars introduced at Ocean Business 2025

Motion Reference Units for vessel performance optimisation in focus at Europort 2025

A year in Motion Reference Units...

Contact us

Motion Compensated Gangways

Motion Compensated Gangways

Motion Reference Units for Motion Compensated Gangways

Why accurate MRU data is critical for Motion Compensated Gangways

Accurate motion measurements in real sea conditions

Proven technology with long offshore track record

Easy integration into existing Gangway Control Systems

Motion Reference Units designed for Motion Compensated Gangways

What our customers say

Contact us