Dynamic Hull Monitoring

Hull Stress Monitoring is a real-time understanding of the forces impacting the vessel. By understanding this information, vessel operators can get a clearer picture of how operations and environmental conditions affect structural loads, helping them avoid excessive stress, improve safety, and optimise vessel performance.

Traditional methods rely on static models, manual calculations or periodic inspections which only take a snapshot at that time, and this may not always accurately capture actual operation conditions. Traditional inspections require frequent checks of known hotspots without real-time indication of when they may become problematic. An advanced Hull Monitoring System allows the degradation of these maintenance hotspots to be projected into the future, giving teams a predictive view of when these areas need immediate attention or when they are not high priority. This dynamic monitoring enables a more proactive understanding of the vessel, including earlier detection of potential issues, increased safety, more informed operational decision, cost savings through targeted inspections and reduced reliance on conservative estimated which helps extend the vessel lifespan.

They provide continuous, up-to-date insight into the vessel's structural condition. This allows operators to make informed decisions based on actual data. Key benefits include but are not limited to a holistic understanding of how the impact of vessel operations affect the overall vessel’s lifetime, early detection of abnormal or high strain values/loads, key instrument and DCS data stored indefinitely for lifetime extension and maintenance optimisation, informed targeted maintenance that highlights the operational impact on maintenance, reduced downtime through targeted inspection and maintenance, improved safety for the crew, vessel, and the cargo and extended vessel lifespan via targeted maintenance and stress reduction, leading to improved return on investment.

Hull Monitoring systems do not need to meet DNV or DNVGL requirements. However, if a vessel seeks the associated class notation for its Smart Hull Monitoring System, the SMS Hull Monitoring System fully complies.

The best hull monitoring systems take a combined approach, incorporating operational data, loading information, and real-time sensors. By integrating this operational and load data, the system reveals how different activities affect the vessel and generates a Structural Health Report. The report's impact analysis on local structural details uses Finite Element (FE) analysis to accurately assess these effects. In collaboration with the vessel owner, the system undergoes known operations to precisely calibrate the sensors. This enables a Risk Based Inspection (RBI) methodology for the critical details identified through the Hull Monitoring System.

The FPSO system mirrors the design for sea-going vessels , with instrumentation placed at key structural points along the hull. This data feeds into the Hull Monitoring System, which actively tracks force impacts at select hotspots across the hull.

Hull monitoring system costs vary based on vessel size and type, number of sensors required, and the level of analysis and integration needed. For offshore vessels and assets like FPSOs, expect £500k–£2m+, covering initial assessment, design, installation, and ongoing support. Costs depend on factors such as system complexity, installation scope, and advanced features like real-time analytics, fatigue assessment, or system integration. Each system is tailored to specific vessel and operational requirements, requiring a detailed assessment for an accurate estimate.

Hull Stress Monitoring primarily uses strain sensors. A full Structural Health Monitoring System can incorporate many more , depending on the vessel operator's requirements. Options include Wave Radars, Inertial Motion Units (IMUs), and Corrosion/Wall-Thickness Monitors—all available in SMS's Structural Health Monitoring System.

Hull Monitoring Systems integrate with digital twins by feeding real-world data directly into models to assess structural impact. This data can also be shared with third parties to verify their existing digital twin models. SMS's Structural Health Monitoring System operates as a Fatigue Life digital twin, delivering the expected fatigue life of critical structural details throughout the vessel's lifetime. This shifts operators from reactive monitoring to predictive decision-making, enhancing safety and optimising maintenance and operations.

Fibre optic strain sensors are mounted at preselected points across the platform. They all connect to a central unit that reports their strain data. These known strains at known points form a structural shape, which SMS's Structural Health Monitoring System interprets to monitor stresses at key structural points.

The recommendations for Hull Stress Monitoring can be found in the following documents for their respective classification society : American Bureau of Shipping ABS (2022) Guide for Hull Condition Monitoring System, July 2020 , American Bureau of Shipping ABS (2022) Smart functions for Marine Vessels and Offshore Units, June 2022, American Bureau of Shipping ABS (2024) ABS-134 Guidance Notes on Safe Hull Finite Element Analysis of Hull Structures, ClassNK (2024) Rules for Installations, Rules for Hull Monitoring Systems, DNV (2021) DNV-CG-0508, Class Guidelines, Smart Vessel, DNV (2025a) DNV-RU-SHIP Pt.6 Ch.11, Ships, Digital Features, DNV (2025b) DNV-RU-SHIP Pt.6 Ch.6, Ships, Survey Arrangements and DNVGL (2015) DNVGL-CG-0127, Class Guideline, Finite Element Analysis.

Hull Potential Monitoring assesses the corrosion risk on the hull. It measures the hull's electrical potential relative to the surrounding environment to verify that cathodic protection systems work effectively , preventing corrosion. Hull Structural Monitoring, on the other hand, tracks the forces affecting the hull—such as operational loads , stresses, and fatigue. It uses sensors to monitor strain, helping operators understand vessel behavior under real conditions and spot potential structural issues. The SMS Structural Health Monitoring System can incorporate both monitorings to meet vessel operators' requirements.

Naval Vessel Health Monitoring Systems adapt a typical Hull Health Monitoring System to meet the rugged requirements of naval operations. Requirements can vary widely between vessels but represent only minor departures from commercial systems.

Hull monitoring delivers ROI through improved safety, reduced operating costs, and extended asset life. ROI varies by vessel size and Hull Monitoring System scope: 1. Pairing it with a targeted maintenance program cuts long-term maintenance costs 2. Optimising operational maneuvers extends fatigue life, enabling assets to operate beyond their design life.

Predictive maintenance uses hull monitoring data to build a digital twin of the vessel’s structure, based on real-world, real-time measurements from installed sensors. This data models the hull's fatigue life under expected operating conditions over coming years. It identifies critical fatigue areas in advance and updates them continuously with real-time sensor data. The system supports early identification of high-risk structural areas, prioritisation of inspections based on actual data, targeted, proactive maintenance planning and reduced focus on low-risk areas, optimising inspection efforts. This enables Dynamic Risk-Based Inspection (DRBI), focusing maintenance where it delivers maximum value and risk reduction.