Support Vessel Research Articles

Risk Analysis of Coral Reef Damage Area due to Grounding Incidents in Karimunjawa National Park

Abstract The designation of Karimunjawa as a National Park in 1999 does not prevent any shipping activities performed by barges, passenger ship, LCT, or even tanker from entering Karimunjawa waters. Such condition can cause damages to coral reefs if the ship run aground. In addition, the possibility of coral reefs contamination due to tourists activities such as diving that requires vessels to transport them. Based on the historical data from 2017 until 2023, fourteen cases of vessel grounding in Karimunjawa were recorded. This study comprises of hazard identiLication, frequency analysis, severity analysis, and risk representation. The simulation result of IWRAP Mk2 shows that the grounding incident in Karimunjawa is 3.736 incidents/year. Meanwhile the projected coral reefs area that affected by the grounding incident reached 0.55% from the total coverage. Based on Risk Management Australia AS/NZS 4360 (2004), the results showed that support vessels have high risk of grounding, followed by passenger ships with a moderate risk level. Tankers and other types of vessels were found to have a low risk of grounding.

Onboard test-based exhaust emission factors for marine diesel engines on anchor handling tug supply vessels

In order to accurately assess China’s port air pollution caused by AHTS (Anchor Handling Tug Supply Vessels) ships, 46 diesel engines on 27 AHTS ships were tested for onboard emissions using a large gas analyzer to statistically analyze their fuel-based and power-based emission factors. The results show that fuel-based NOx-emission factors for MEs, SEs and AEs before and after the use of the SCR system are 45.4, 38.24,33.04 g/kg and 6.35, 4.98, 5.82 g/kg, CO-emission factors are 7.95, 6.30, 7.96 g/kg and 6.90, 6.93, 8.32 g/kg, THC-emission factors are 0.49, 0.64, 0.25 g/kg and 0.42, 0.47, 0.22 g/kg, and CO2-emission factors are 3121.62, 3121.34, 3093.12 g/kg and 3088.14,3091.40, 3085.21 g/kg, respectively. Power-based NOx-emission factors for MEs, SEs and AEs before and after the use of the SCR system are 9.71, 8.61, 7.58 g/(kW·h) and 1.37, 1.23, 1.33 g/(kW·h), CO-emission factors are 1.71, 2.08, 1.84 g/(kW·h) and 1.47, 1.53, 1.93 g/(kW·h), THC-emission factors are 0.10, 0.14, 0.05 g/(kW·h) and 0.09, 0.13, 0.06 g/(kW·h), and CO2-emission factors are 671.73, 700.58, 718.46 g/(kW·h) and 664.42, 694.16, 716.92 g/(kW·h), respectively. The power-based emission factor is closely related to the diesel engine load, and the relationship between different exhaust emissions and diesel engine load shows different patterns. In addition, it was found that the NOx emissions of the ship decreased significantly to meet the IMO Tier III requirements after running SCR. The emission factors of CO, HC and CO2 have no obvious change whether SCR systems were operated or not. The AHTS marine engine emission factors obtained in this paper are highly relevant and can provide reliable data for establishing a suitable emission inventory for medium and high speed engineering support vessels.

Watercraft as Overwater Ambulance Exchange Points to Enhance Air Medical Evacuation

Ambulance exchange points are preidentified sites where patients are transferred between evacuation platforms while en route to enhanced medical care. We propose a new capability for maritime medical evacuation, which involves co-opting underway watercraft as overwater ambulance exchange points to transfer patients between medical evacuation aircraft. We partnered with the US Army's 25th Combat Aviation Brigade to demonstrate the use of Army watercraft as overwater ambulance exchange points. A manikin was transferred between 2 HH-60M medical evacuation Black Hawk helicopters conducting hoist operations over Army Logistics Support Vessel 3, which was traveling south of Honolulu, HI. The demonstration was enabled by a decision support system for dispatching aircraft, hoist stabilization technology, commercial satellite internet, military geospatial infrastructure applications, and digital medical documentation tools, the benefits of which are all discussed. Three extensions of the overwater ambulance exchange point are introduced, and civilian applications are considered.

Cable length prediction for towing models of reverse towing systems based on the cable deployment process

Given the dynamic depth changes of the underwater support vessel in the reverse towing system, the vessel needs to continuously adjust the cable length by reeling in or out to ensure that the towed body is stably towed at the designated position. Therefore, this paper considers the impact of the cable deployment process on cable length prediction and proposes a model that can dynamically predict the required cable length for the towed body at the designated position. A floating tow experiment was conducted in a towing tank, and the predicted and experimental cable length data were compared to verify the accuracy of the dynamic cable length prediction algorithm. The lift height of the towed body was compared between the proposed model and the traditional model to verify the validity of the model. The relative error between the predicted cable lengths and the experimental data was 3.8%. The relative error in the lift height between the proposed model and the traditional model was 7.2%. The proposed model can continuously and accurately predict cable length, allowing the underwater support vessel to continuously adjust the cable length, thereby ensuring the stable operation of the towed body at the designated operational position.

Assessing the Impact of Ship-Sourced Marine Pollution on Filyos Port

In 2021, Turkiye launched the Filyos Valley Project, a strategic initiative with the potential to serve as both a central hub for the transfer of Central Asian oil to the West and as a logistical bridge between China and Europe. Located near the city of Zonguldak in northern Turkiye, this project encompasses a range of logistical components, including the extensive and high-capacity Filyos Port, which is the third-largest port in the country. The port is situated in close proximity to the Sakarya gas field in the Western Black Sea, Turkiye's largest natural gas production area, and currently serves as a base for natural gas drilling ships and their support vessels. Filyos Port plays a crucial role in Turkiye's energy security due to its strategic location near the Istanbul Strait, a key convergence point for maritime traffic in the Black Sea. However, this proximity also poses a significant risk; pollution from a maritime accident along the approach routes to the Strait could severely disrupt the port's operational capabilities. This study aims to analyze the behavior and spread patterns of ship-sourced oil pollution near Filyos Port and to determine the timeframe within which the port would be exposed to such pollution. This research offers a comprehensive framework for port authorities to develop effective contingency plans, ensuring operational sustainability and enhancing the region’s energy security by mitigating the risks of marine pollution.

Model experimental studies on active heave compensation control strategy for electric-driven offshore cranes

Ship-mounted heave compensation offshore cranes are indispensable for isolating connected payloads from the support vessel during lifting operations under harsh sea conditions. In this paper, an innovative adaptive robust control strategy is presented for the electric-driven active heave compensation (EDAHC) system, combining an equivalent model predictive control (EMPC) method with a bias proportional integral derivative (BPID) framework to effectively mitigate the adverse effects of wave-induced heave motions from the support vessel on the suspended payload. Building upon the inherent field-oriented control in the permanent magnet synchronous motor (PMSM), the BPID-based control structure is introduced, motivated by its prompt responsiveness and robust resistance against model discrepancies and irregular disturbances. Facilitated by a torque compensation mechanism, the EMPC-based control scheme, synthesized with an autoregressive integrated moving average (ARIMA)-based heave motion prediction algorithm, is subsequently developed to achieve nonlinear friction deadzone correction and adaptive regulation of BPID parameters, thereby ensuring optimal performance of the EDAHC system within specified state and input constraints. Comparative experimental tests conducted on a scaled EDAHC testbed validate the superior capabilities of the proposal in station-keeping, position tracking, constraint satisfaction, and robustness against parametric uncertainties.

Digitalization of Anchor Handling Tug Supply Vessels: Enhancing Efficiency and Safety in Offshore Operations

Abstract Global demand for safety and sustainable offshore operations has led to great and dynamic changes in the maritime and offshore industry in recent years. This has made the industry to witness a rapid transformation in recent times with the digitalization of vessels, and anchor handling tug supply (AHTS) vessels are no exception. The digitalization of offshore operational vessels is expected to play an important role in the future and support the analysis of the automation and instrumentation market. The AHTS vessel is a specialized offshore support vessel used in the oil and gas industry, which serves multiple functions and roles that provide support for offshore drilling and production operations. The multi-functional purpose of AHTS vessels includes anchor handling, towing, supply and cargo transportation, oil spill clean-up response, and cable and pipe laying, among others. This requires the integration of multiple functional digitalized systems to optimize vessel operations, especially in harsh arctic environments. The current study reviews the importance and potential of AHTS vessels' digitalization and discusses its benefits, opportunities, and challenges. A systematic approach is adopted to explore the potential development and dynamics of digitalization in the maritime industry, focusing on AHTS vessels. This study finds that the extent of knowledge is evolving and requires an integrated approach to maritime digitalization to enhance operational efficiency, safety, and resilience in critical offshore operations.

Corrosion Resistance of Biodegradable Zinc Surfaces Enhanced by UV-Grafted Polydimethylsiloxane Coating.

Improved living conditions have led to an increase in life expectancy worldwide. However, as people age, the risk of vascular disease tends to increase due to the accumulation and buildup of plaque in arteries. Vascular stents are used to keep blood vessels open. Biodegradable stents are designed to provide a temporary support vessel that gradually degrades and is absorbed by the body, leaving behind healed blood vessels. However, biodegradable metals can suffer from reduced mechanical strength and/or inflammatory response, both of which can affect the rate of corrosion. Therefore, it is essential to achieve a controlled and predictable degradation rate. Here, we demonstrate that the corrosion resistance of biodegradable Zn surfaces is improved by electroless deposition of zinc hydroxystannate followed by UV-grafting with silicone oil (PDMS). Potentiodynamic polarization, electrochemical impedance spectroscopy, respiratory kinetic measurements, and long-term immersion in three simulated body fluids were applied. Although zinc hydroxystannate improves the corrosion resistance of Zn to some extent, it introduces a high surface area with hydroxyl units used to UV-graft PDMS molecules. Our results demonstrate that hydrophobic PDMS causes a 3-fold reduction in corrosion of Zn-based materials in biological environments and reduces cytotoxicity through the uncontrolled release of Zn ions.

Исследование характеристик стационарных режимов движения подводной привязной системы «ТНПА – кабель – судно»

The efficiency of using uninhabited underwater vehicles of the tethered type is associated with the need for its propulsion and steering complex (PSC) to compensate for the reaction of the communication cable of the device with the support vessel when maneuvering near the work site. The work examines the achievable boundaries of the maneuvering zone of a remotely controlled uninhabited underwater vehicle (ROV) for known values of the length of the communication cable, the submersion depth of the device, the current speed in the work area and the traction characteristics of the PSC. Algorithms for determining the boundaries of the working area and the achievable speed of the apparatus are presented, based on calculating the tension at the ends of the communication cable in a stationary flow, using the equations of a catenary line and the numerical integration of the equations of an inextensible flexible thread. In order to increase the operational reliability of underwater technical work, recommendations have been developed for choosing a cable length that prevents it from sagging below the submersion depth of the apparatus with possible snagging and damage by bottom objects. During the model experiment, the boundaries of the maneuvering zone were assessed relative to the coordinates of the carrier for a promising ROV with known hydrodynamic resistance and traction characteristics of the PSC, as well as the dependence of the achievable speeds of the vehicle within the maneuvering zone on the immersion depth and the speed of the oncoming current.

Cascade NMPC-PID control strategy of active heave compensation system for ship-mounted offshore crane

In this paper, the problem associated with active heave motion compensation during heavy-lift operations performed by ship-mounted offshore cranes beneath rough marine environment is investigated. To effectively decouple the correlated motion of the suspended payload from the support vessel via the secondary regulated active heave compensation (SRAHC) system, a novel hierarchical control strategy is proposed by integrating a cascade control structure with an adaptive robust control scheme that incorporates a vertical motion forecast algorithm based on autoregressive integrated moving average (ARIMA) model, a conventional proportional-integral-derivative (PID) framework, and a nonlinear model predictive control (NMPC) method. The introduction of the cascade structure is motivated by its prompt error response against control lag and efficient system order reduction for computational burden alleviation, which forms a crucial foundation for the NMPC-based real-time regulation of PID gains, ensuring optimal evolution of the SRAHC system while improving its practical feasibility. Furthermore, the enhancements in heave compensation and trajectory tracking performance, noise resistance, constraint satisfaction, and engineering application potential of the proposal are demonstrated through a thorough comparative analysis conducted in a practical co-simulation research system.

Станция подводного обслуживания гибридного необитаемого подводного аппарата системы мониторинга подводного добычного комплекса

The use of support vessels significantly increases the cost of monitoring objects of underwater production complexes (UPC), and the presence of a cable communication line significantly limits the possibility of using remote-controlled uninhabited underwater vehicles (ROV), which is reduced to zero in conditions of continuous ice coverage of the work area. An obvious alternative to the use of ROVs are autonomous uninhabited underwater vehicles (AUVs), equipped with equipment for conducting contact work with monitoring objects and communicating with the shore control post. At the same time, the necessary autonomy for the use of such hybrid autonomous uninhabited underwater vehicles (HAUVs) can be ensured by a network of bottom stations equipped with systems for contactless charging and information exchange with the shore UPC control post. The work proposes the concept of an underwater service station (USS) for a HAUV, which allows, in long-term underwater deployment conditions, to use the device not only in an autonomous mode, but also in a remote control mode from a shore control post. A model for using the station for its intended purpose and the composition of the equipment necessary for its implementation have been determined, the design of the technical solution of the station has been presented, determined taking into account the features of installation on a complex bottom surface and the requirements for docking the HAUV for contactless charging and information exchange, including in the mode of remote control from the SCP. Basic technical solutions for the USS have been developed that provide automatic adjustment of the horizontal position of the docking unit, reliable docking and holding of the HAUV charging and information exchange terminals, and control of the vehicle’s pointing process using a set of rotary video cameras with lamps and a sector-view sonar. Algorithms for interaction between the station and the HAUV have been developed for autonomous and controlled via optical communication cable operating modes of the vehicle.

Nonlinear slackness anatomy during vertical installation of heavy devices in deep water

The vertical lowering of subsea equipment is one of the most used installation methods. Consisting of the lowering of the equipment by using a cable connected to a crane located on a support vessel, this method is usually more straightforward than others. However, the vertical stiffness of the system depends on the cable's length, meaning that the natural frequency of vertical motions will vary along the lowering of the equipment. At some water depths, the natural frequency will be close to the typical wave frequency of the region, which will lead to a dynamic amplification of these motions, which can lead to the slackness of the cable, that is, there will be zero tension on the cable. The lack of stiffness due to the slackness means that the equipment's submerged weight will be responsible for bringing the equipment downwards, leading subsequently to higher tension peaks usually known as snap loads. The current recommendation by the classification societies is to avoid installing under environmental conditions when slackness occurs. However, based on the understanding of the nonlinear anatomy when the cable is slack, the present work shows that it would be possible to increase the operation window.

Optimization Model for Selection of the Offshore Fleet Structure

Over the past century, with an accelerated increase in world energy demand, oil remained the most intriguing energy source, while oil exploration and production evolved from an onshore to an offshore exploration and production facility. In logistic and operational planning, the supply of offshore installations is the primary dependent of offshore supply vessels (OSVs). OSVs are classified into two main specialized groups, Anchor Handling Tug Supply (AHTS) and Platform Supply Vessels (PSVs). The establishment and maintenance of offshore oil installations require considerable financial resources for the hire of OSVs, which increases the oil exploration and production operator’s overall budget. Planning the offshore fleet structure aims to reduce expenses and increase the utilization of OSVs. This work will analyze the actual data of the southwestern African offshore market based on 24/7 working time and the use analysis of marine activities to define the parameters of the offshore fleet structure. The research results will be used to develop a methodology for modeling the optimal infrastructure of the offshore fleet. With statistical data of all support vessels’ activities and the use of linear programming (LP), it is possible to determine the vessel’s employment pattern and the optimal fleet structure by type and number of OSVs.

Optimization of Preventive Maintenance Strategies for Electrical Equipment on Offshore Oil Support Vessels Based on Predictive Maintenance Algorithms in an Intelligent Platform

Optimization of Preventive Maintenance Strategies for Electrical Equipment on Offshore Oil Support Vessels Based on Predictive Maintenance Algorithms in an Intelligent Platform

A Back–Forward Approach-Based Efficiency Performance Analysis Model for Hybrid Electric Propulsion Ships Using the Holtrop–Mennen Method

Due to tightening regulations on exhaust emissions from ships, there is a growing need to develop electric or hybrid electric propulsion systems to replace conventional diesel-based ship power systems. The hybrid electric propulsion system is suitable for small and medium-sized vessels and its energy efficiency significantly depends on the arrangement of different power sources, power control strategies for energy sources, and energy storage system (ESS). Therefore, an analytical simulation to evaluate the energy efficiency of ships with their structure and control strategies is needed. In this study, a back–forward approach-based efficiency performance analysis model was developed using the Holtrop–Mennen resistance model to calculate ship resistance and power demand based on a given ship’s speed profiles. This model has the advantages of using easily obtainable ship speed profiles as the input and can be modularized for each power source and ESS, incorporating mechanical performance limitations, and allows for rapid analysis. The developed analytical model was applied to a hybrid electric propulsion system in a marine support vessel and its energy efficiency was evaluated by establishing rule-based power control strategies. As a result, the engine efficiency of the hybrid electric propulsion system increased from about 27% to 30% compared to the existing system, and the final effect of reducing fuel consumption by about 10% compared to the existing system was confirmed through the developed simulator. In the future, this analytical model could be utilized to derive the optimal layout of hybrid electric propulsion systems, and to formulate power control strategies.

ANALYSIS OF APPLICATION POSSIBILITIES AND CLASSIFICATION OF UNMANNED AERIAL VEHICLES FOR THE SUPPORT OF COMBAT OPERATIONS OF THE NAVY OF THE ARMED FORCES OF UKRAINE

Nowadays, in the course of war between Ukraine and the russian federation, there is a large-scale employ of various weapon systems that are used on land, in the air, and at sea. Unlike the enemy, Ukraine Forces prefer to utilize asynchronous methods of armed struggle. In order to successfully implementation of these asynchronous methods is necessary used to contemporary unmanned aerial vehicles and unmanned air systems. It is known that at the beginning phase of the war the Ukrainian defenders were used unmanned aerial vehicles and unmanned air systems on the principle of “controlled chaos”. As a result of these active operations, the Ukrainian defenders could discourage and defeat enemy. Therefore, in order to secure effective usage of unmanned aerial vehicles and unmanned air systems it is necessary to introduce a clear hierarchy with clear classification features. This task is certainly relevant today for Ukrainian NAVY. It is the significant task, because the Ukrainian NAVY has some experience in the combat use of unmanned aerial vehicles and unmanned air systems, but they need its systematization and comprehensive implementation, taking into account the specifics of conducting combat operations at Black sea. At the same time, in order to improve functionality and effectiveness of the unmanned aerial vehicles and unmanned air systems the developers must apply information technologies such as, internet of military things, cloud technologies and artificial intelligence. For instance, if developers wanted to implementation of internet of military things technologies, they would be able to ensure intercommunication among different groups of aerial vehicles and simplify to control process of them.
 In the proposed paper, the authors tried to perform capabilities analysis of usage of different types unmanned aerial vehicles and unmanned air systems with various control systems and military categories based on the use of NATO standards. In addition, the authors performed this analysis considering different types Ukrainian NAVY ships and support vessels. Moreover, the authors of the paper also proposed a classification for unmanned aerial vehicles of Ukrainian NAVY.

Assessing Occupational Stress in Seafaring: A Fuzzy Delphi Approach to Develop Effective Management Strategies in Offshore Support Vessel Operations

The maritime industry has long been a crucial component of Malaysia's economy. Seafarers in this industry face unique psychosocial, work-related, and environmental stressors, which can negatively impact their health, safety, and well-being. The operations of offshore support vessels (OSVs) are particularly hazardous and require effective strategies for occupational stress management. The Fuzzy Delphi method was used to identify the key enablers of occupational stress in OSV operations. The study has found that the main enablers of occupational stress in seafaring include vulnerability towards occupational hazards and risks, human capital skills, onboard living conditions, governance capacity, and mental burnout. These findings can help guide efforts to address the occupational stressors faced by seafarers serving on OSVs and enhance their working conditions, skills, and health. Shipping companies, policymakers, and organisations must collaborate to ensure the compliance with marine regulations and standards, improve shift schedules, and implement proper mechanisms to maintain the occupational health of seafarers during and post the Covid-19 pandemic.

Comparative life cycle impact assessment of offshore support vessels powered by alternative fuels for sustainable offshore wind operations using machine learning

Offshore Anchor handling tug supply (AHTS) vessels, a type of offshore support vessel, are critical for the operations related to handling anchors of offshore structures, oil rigs, and wind turbines, towing them to remote deep-sea locations, and securing them in place. Amidst growing concerns regarding the environmental footprints of carbon-based fuels and impending carbon taxation, the International Maritime Organization, policymakers, classification societies, shipping firms, and stakeholders are seeking cleaner alternatives. LNG (Liquefied natural gas) and Green ammonia as energy vectors are considered among the top contenders for future clean alternatives for offshore vessels. This study evaluated the environmental performance of newly built AHTS vessels powered by LNG and Green ammonia as marine fuels designed for offshore operations. This environmental impact assessment study uses IPCC and Environmental footprint methodologies. Considered broad impact groups: Global warming, human toxicity, eutrophication, ecotoxicity, and atmosphere-related impacts, and analyzed the process impacts. This study uses Supervised machine learning algorithms such as the Random forest, Decision tree, and XGBOOST models for environmental performance evaluation and prediction. The study reveals that the recently manufactured AHTS vessel, utilizing conventional fuels like Heavy fuel oil, Marine diesel oil, and LNG, exhibits significantly increased GTP 100 and GWP 100 emission levels per tonne-kilometer when compared to green ammonia, with a 44 % and 10.6 % rise compared to Heavy fuel oil, respectively. Furthermore, the XGBOOST regression model outperformed the Random forest and Decision tree models in predictive accuracy for GWP 100. It is analyzed and proposed that effectively managing unsustainable processes would minimize environmental footprints and reduce carbon, nitrogen oxide, LNG, and ammonia-based emissions.

NMPC-PID control of secondary regulated active heave compensation system for offshore crane

In this paper, an offshore crane driven by a secondary controlled unit (SCU) which offers advantages in terms of high dynamic behavior and energy efficiency is investigated. To counteract the negative impact of the support vessel's heave motion on the station-keeping and trajectory tracking performance of heavy payload, an adaptive robust control scheme for the secondary regulated active heave compensation (AHC) system is proposed based on the combination of a nonlinear model predictive control (NMPC) strategy, a conventional proportional-integral-derivative (PID) control scheme and a vessel heave motion prediction algorithm. The motivation of utilizing the PID-based control structure is given by the excellent resistance against irregular external disturbances and robust capability to eliminate the uncertainties, with real-time tuning gains provided by the NMPC synthesized with the autoregressive integrated moving average (ARIMA) model to ensure optimal evolution that satisfies state and input constraints while accounting for model nonlinearities. Comparative simulation studies in the practical Simulink-based mechanical-electrical-hydraulic research system demonstrate the superior tracking and heave compensation performance, strong robustness, constraint satisfaction, and energy efficiency of the proposal.

Construction of a Small-Scale Tugboat

Support vessels for other ships emerged to provide specialized assistance in port logistics. Among these support vessels are tugboats. In this logistics, a tugboat that has an ineffective propulsive system will cause poor support, bringing losses to the sector's production chain. The problem addressed in the work aims precisely to present the construction process of tugboats as complex and dynamic, but at the same time allows to achieve very favorable results in terms of teamwork and the use of computer simulation in the process of projecting parts and components. This work presents the process of building a tugboat on a reduced scale, the elements mentioned here are valid for the construction of tugboats at any scale, which reaffirms the importance and topicality of the theme addressed. The procedures for the construction of the 2017 naumodel were described. Hull designed in DELFTship. The construction of the tug was made by cuts in welded 3mm aluminum sheets. The propellers designed using 3 software: NavCad, PropCad and SOLIDWORKS, cast through 3D molds printed on ABS molds. Magnification box designed, using parameters from NavCad results, in Autodesk Inventor, model 1:1.2. Axis and alignment of the motors carried out in order to reduce the maximum losses.Palavras chaves: rebocador, projeto mecânico.