Precise motion measurements are essential for LNG carrier operations, supporting sloshing management, structural health monitoring of cargo containment systems, fuel optimisation, and regulatory compliance.
With accurate real-time data on roll, pitch, heave, and all six degrees of freedom, Norwegian Subsea MRUs give LNG operators continuous insight into the vessel motions that drive sloshing risk in prismatic cargo tanks. By correlating vessel motion with sea conditions and tank fill levels, operators can make informed decisions to protect containment system integrity, extend inspection intervals under condition-based survey programmes such as DNV's Alternative Survey Programme (ASP), and maintain structural health throughout the vessel's operational life.
With growing IMO reporting requirements, most LNG operators already have flowmeters integrated into their vessel performance software — but motion data remains a missing piece. Adding an MRU closes that gap, enabling more accurate performance benchmarking, emissions reporting, and critically, the motion records required to document operational conditions within approved design limits for cargo containment systems.
Motion data feeds directly into digital twin models, fuel optimisation algorithms, sloshing management systems, and predictive maintenance programmes — enabling smarter decisions for vessels where cargo integrity and structural health are as important as operational efficiency.
Retrofit an MRU onto your LNG carrier today to reduce fuel costs, meet tightening emissions regulations, support condition-based survey requirements, and protect the long-term integrity of your cargo containment system.
Motion Reference Units (MRUs) play a central role in sloshing management for LNG carriers by providing the precise, real-time vessel motion data that underpins every aspect of a sloshing risk assessment. Sloshing, the violent movement of liquid cargo inside partially filled prismatic tanks, is directly driven by vessel motions, and understanding that relationship is critical to protecting both the cargo containment system and the structural integrity of the vessel.
By continuously measuring roll, pitch, and heave across all six degrees of freedom, MRUs give operators an accurate, real-time picture of how the vessel is responding to sea conditions. This data is fed directly into sloshing management systems, enabling dynamic risk assessment and informed operational decisions, such as adjusting heading, speed, or tank fill levels — before critical motion thresholds are reached.
Prismatic LNG tank containment systems are designed to withstand specific motion envelopes. MRU data allows operators to continuously verify that vessel motions remain within those design limits, protecting the membrane and insulation systems from fatigue damage caused by repeated sloshing impacts over the vessel's lifetime.
Under classification society programmes such as DNV's Alternative Survey Programme (ASP), continuous MRU motion records can be used to demonstrate that operational conditions have remained within approved design assumptions — supporting reduced physical tank inspections and providing documented evidence for surveys and audits.
Historical and real-time MRU data feeds into voyage planning tools, helping operators anticipate high-motion conditions and adjust routes or loading strategies proactively — reducing both sloshing risk and unnecessary wear on the containment system.
50 m depth, IP 68
5 cm or 5.0%
Lemo or SubConn 8 or SubConn 16
IP 65
5 cm or 5.0%
RJ45 or RJ50
"Norwegian Subsea MRUs had the accuracy, the temperature range, and the enterprise-level quality we required"
"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."
