Support Vessel Research Articles

Autosub Long Range 1500: A continuous 2000 km field trial

Long Range Autonomous Underwater Vehicles (LRAUVs) offer the potential to monitor the ocean at higher spatial and temporal resolutions compared to conventional ship-based techniques. The multi-week to multi-month endurance of LRAUVs enables them to operate independently of a support vessel, creating novel opportunities for ocean observation. The National Oceanography Centre’s Autosub Long Range is one of a small number of vehicles designed for a multi-month endurance. The latest iteration, Autosub Long Range 1500 (ALR1500), is a 1500 m depth-rated LRAUV developed for ocean science in coastal and shelf seas or in the epipelagic and meteorologic regions of the ocean. This paper presents the design of the ALR1500 and results from a five week continuous deployment from Plymouth, UK, to the continental shelf break and back again, a distance of approximately 2000km which consumed half of the installed energy. The LRAUV was unaccompanied throughout the mission and operated continuously beyond visual line of sight.

FROG: A PORTABLE UNDERWATER MOBILE MAPPING SYSTEM

Abstract. Browsing the scientific and professional literature it appears that the concept of mobile mapping underwater is not as common as in ‘terrestrial’ applications. Nevertheless, exploring and mapping the ocean’s depths is a priority challenge for humankind, today more than ever. Radio waves, such as the GNSS or UWB signal, have a very limited transmission underwater, resulting in the absence of an underwater global positioning system. Consequently, the main sounding methods (i.e., depth measuring systems) are based on the fusion of inertial and acoustic sensors, which allow for systematic mapping of vast seafloor areas. However, photogrammetric surveying methods are preferred when high resolution and reliable colour information are essential aspects in the project economy. This class of approaches include visual odometry and visual SLAM (vSLAM), which represent a valid tool for navigation and positioning in GNSS-denied environments, such as underwater. In this paper, we present a portable underwater mobile mapping system, named FROG, which implements a vSLAM based solution to guide the survey according to photogrammetric principles. FROG is built upon the Guided Photogrammetry - GuPho concept and, thanks to its modular design, can be used by a diver or installed on a micro ROV and controlled remotely from a support vessel. In the paper, FROG characteristics will be detailed, and its potentialities demonstrated in real case applications at sea and in lakes.

Investigating aerial diversity of non‐fungal eukaryotes across a 40° latitudinal transect using DNA metabarcoding

AbstractThe high number of bipolar and widespread bryophyte and microbial taxa in the Antarctic flora suggests the effective Long‐Distance Dispersal (LDD) of spores and other propagules from lower latitudes and even the Northern Hemisphere to Antarctica and the sub‐Antarctic regions. However, few studies have attempted to document the transfer mechanisms by which potential newcomers may arrive in Antarctica. Commonly suggested or assumed mechanisms include transport in air currents, adventitious transfer with migrating or vagrant birds, and with human assistance. In this study, we investigated the biodiversity present in the air along a 40° latitudinal transect, from the port city of Rio de Janeiro, Brazil (ca. 22°S) to Comandante Ferraz Station on King George Island (South Shetland Islands, ca. 62°S), maritime Antarctica, to shed light on the potential role of LDD in species distribution. Air samples were collected in October 2021 on the Brazilian polar support vessel Ary Rongel using air filters with membranes of 0.22 μm. Total DNA was extracted from the filters and the Internal Transcribed Spacer (ITS2) DNA sequence was used for metabarcoding. A total of 53 non‐fungal taxa representing three kingdoms (most abundantly Viridiplantae) and six phyla (most abundantly Bryophyta and Magnoliophyta) were assigned from the sequences found. Aerial biodiversity was greater closer to the coast and generally decreased with increasing latitude, although a small increase was apparent in the South Shetland Islands. The taxa assigned are generally present in coastal biomes, although a small proportion of the assignments represented taxa of more distant origin, supporting the occurrence of LDD in the air column.

Evaluation of Electric Power Quality in the Ship-Integrated Electrical Power System with a Main DC Bus and Power Semiconductor Electric Drives as Part of the Electric Propulsion Complex

The relevance of the work is connected to the energy efficiency of specialized vessels of the technical fleet. The purpose of the study was to determine and evaluate the power quality indicators associated with the non-sinusoidal shape of the voltage and current curves in the electrical power system of the marine platform support vessel, which contains powerful semiconductor propulsion electric drives, taking into account the inherent and parasitic parameters of the power three-phase cable lines. A simplified one-line diagram of an electric power system with a DC main bus was the object of the study, which was compiled as a result of the analysis of analog systems typical for the indicated type of vessels. The phenomenon of voltage and current distortion caused by the presence of higher harmonics generated by power semiconductor converters in a three-phase ship network was the subject of the research. For the experimental study of the quality of electric power according to the simplified one-line scheme of the electric power system in MATLAB Simulink, its model was created. Based on the proven methods of calculating the ship’s electrical equipment, a methodology was developed for the reliable determination of model parameters. According to the results of the experiment in MATLAB Simulink, qualitative and quantitative indicators were obtained regarding the non-sinusoidality of the linear voltage and current of the three-phase network (curve shapes, amplitude spectra, distortion coefficients), and their comparative analysis with the current norms and standards was performed. In contrast to the previous ones, the methodology for assessing the quality of electricity in the studied electric power system takes into account its circuit, mode features, and the presence of a parasitic capacitance “phase to ground” of a three-phase network, and it can be used in solving similar non-trivial tasks for various similar structurally modified systems.

Holistic and sustainable design optimization of Arctic ships

This paper reviews challenges of relevance to the future development of Arctic sustainable shipping by considering future demands for vessel types, available alternative energy sources, and novel technologies. Results reveal the need to extend existing concept ship design methods to account for the holistic yet sustainable design of Arctic vessels. Accordingly, the paper introduces a decision support framework for holistic and sustainable optimization of the concept design of Arctic ships for different cold regions and purposes of operation. The method presented simultaneously accounts for eco-efficiency, cost-efficiency, and safety. Demonstration for the case of a battery-driven Arctic offshore wind farm service and offshore support vessels shows that optimized designs could outperform their existing environmentally and economically efficient counterparts.

Режим слежения за целью на современных судах, оснащенных системой динамического позиционирования (DP)

The article highlights the results of studying the follow target mode on board the ships equipped with dynamic positioning (DP) systems. There is analyzed the position of a ship in a follow target mode when the DP mode is on, as well as the ability of a ship following a target to hold the position and course under given environmental conditions. Ships equipped with the DP system have strict requirements regarding the parameters of the follow target mode. There are listed the advantages for specific operations: technical servicing the oil and gas fields, examining the pipelines, hydrographic surveys, etc. Functionality of the hydroacoustic reference system, which is the main component of the ship follow target system, is studied. It has been stated that the follow target mode allows the ship to follow the target automatically. In most cases, the target is an unmanned remotely operated vehicle (ROV). ROV is a robot performing specific tasks under water controlled from the ship. ROV support vessels specialize on such operations. The ROV equipment and capabilities depend on the complexity of the task. The simplest tasks are inspection of the pipeline, platform supports, watching divers, visual inspection of an object lowered to the bottom, etc., when ROV is equipped with cameras, searchlights and, occasionally, sonars. To carry out the construction work or maintain the underwater facilities there are needed the servicing ROVs equipped with tools for specific purposes. There has been illustrated a model chart of the ship motion and dislocation of the ROV working area. Connection between ROV and the ship by means of a fiber optic cable is considered in detail, the advantages and disadvantages of this connection are listed. Conclusions are drawn about the widespread use of DP systems on modern ships, in particular those operating in the oil and gas industry, as well as in other areas of marine operations.

Recovery of a Lost Subsea Asset at Full Ocean Depth in the Mariana Trench (10,925 m ± 4) Using a Crewed Submersible

Abstract In 2019, the Deep Submergence Support Vessel Pressure Drop embarked on the third leg of the Five Deeps Expedition. Over the course of 10 days, the full ocean depth submersible Deep Submergence Vehicle Limiting Factor made a record five dives to the bottom of the Mariana Trench: four to the Challenger Deep, one to the Sirena Deep. The submersible was supported by three scientific landers, one of which became stuck on the seafloor at 10,925 m depth. Here we describe how, during the third dive of the campaign, the expedition utilized the submersible to rescue this lost asset from full ocean depth. The expedition was not only significant for its operational jump from single full ocean depth dives to multiple dives in a short space of time, but demonstrated that assets lost in the deepest 45% of the oceans are no longer irretrievable.

Carbon dioxide mitigation from public procurement with environmental conditions: The case of short-sea shipping in Norway

We investigate the potential for greenhouse gas (GHG) emission cuts for the Norwegian short-sea (domestic) maritime segments of express boats, offshore support vessels, and aquaculture support vessels in comparison to ferries in Norway. Public procurement conditional on climate-friendly operation is catalyzing a transition to battery-electric operation, where most ferries will be battery-electric or fueled by hydrogen by 2030. The comparison to ferries is performed with the help of a methodology inspired by the multi-attribute utility method, which contains 11 features related to technology, operation, and acceptance. This score is used to adjust the 70% CO2 emission reduction achieved by ferries. Based on this methodology, the CO2 emission reduction potential for express boats, offshore support vessels, and aquaculture support vessels is estimated to be 46%. Consequently, these short-sea shipping segments could reduce CO2 emissions by 0.8 million tonnes from 2017 to 2030, which is equivalent to 1.5% of Norwegian emissions in 2017. Norway's experience indicates that there is a sizable potential for reducing CO2 emissions for public procurement conditional on climate-friendly solutions for short-sea shipping in other shipping nations.

Shore power connection for offshore vessels - Measured noise reduction in port and dock

The presentation will summarize measured noise reduction for drilling, pipelay and offshore support vessels due to shore power connection. The noise level at office or storage building in distance of 100-250 m from the vessels has been registered continously through days and nights. Noise levels at nights without and with shore power connection has been compared. A drilling vessel had Lw 110 dB and a noise reduction due to shore power connection of 18 dB. A pipelay vessel had Lw 105 dB without shore power, and a noise reduction of 15 dB due to the effect of shore power. Both drilling and pipelay vessel seem to have Lw of 90-92 dB with shore power connection. Two different offshore support vessels have also been measured with sound power level Lw of 107 dB and 100 dB. The noise reduction with shore power connection is 13 dB for the first and 6-7 dB for the latter. With shore power connection, both offshore suppert vessels have Lw of 94 dB. The sound power level with shore power connection seems to be limited by the fact that ship noise level from ventilation and fans seems to be the same.

Some relationships between build strategy and shipbuilding time in European shipbuilding

The build strategy of a ship specifies what is to be produced how, when, where and with what resources. Although it has been emphasised to play an important role in determining shipbuilding time and cost, scientific research on build strategy is limited. In this study, we focus on three interrelated build strategic factors of particular importance in European shipbuilding: hull production offshoring, pre-erection outfitting and the overlap between engineering and production. The study investigates how each of these three factors relates to physical ship production time and to total ship delivery time from contract signing to delivery. We use multiple linear regression on data about European shipyards and the ships they have built, which were obtained from a questionnaire and ship databases. The sample consists of 76 specialised ships, predominantly offshore support vessels, fishing vessels, ferries and other non-cargo carrying vessels, built at 24 European yards. The results provide evidence that yards practicing hull production offshoring have shorter ship production and delivery times than yards building the hulls at their own premises, even though the practice of offshoring itself is likely to have an adverse effect on shipbuilding time. The study also found a significant relationship between the level of pre-erection outfitting and physical production time. On the other hand, overlapping engineering and production only seems to have a limited impact on the production and the delivery time. Several of our results challenge established thinking and provide new insights into the factors affecting production and delivery time in European shipbuilding.

Dynamic Analysis of Full-Circle Swinging Hoisting Operation of a Large Revolving Offshore Crane Vessel under Different Wave Directions

Waves have an important influence on the motion performances of offshore crane vessels. The floating crane vessel in waves gives rise to the motion of the lifted object which is connected to the hoisting wire. Based on the geometric parameters of a revolving offshore crane vessel, combined with the specific process of the floating crane vessel at work, a model of the offshore crane vessel under full-circle swing hoisting has been established by OrcaFlex. With the change in wave direction, the dynamic response of the system is made and the impact force between the support vessel and the hanging object and the tension of the crane wire under different wave directions is obtained. At the same time, the minimum impact forces between the support vessel and the hanging object and the tension of the crane wire and their wave directions are obtained. According to the calculated result, the optimal design of the full-circle swing hoisting operation of large revolving offshore crane vessel has been determined.

A review of accelerated decompression from heliox saturation in commercial diving emergencies.

Saturation diving is a specialised method of intervention in offshore commercial diving. Emergencies may require the crew to be evacuated from the diving support vessel. Because saturation divers generally need several days to reach surface, the emergency evacuation of divers is based on dedicated hyperbaric rescue systems. There are still potential situations for which these systems cannot be used or deployed, and where an emergency decompression provides an alternative solution. Our objective was to describe historical cases and assess the benefit of emergency decompressions, with the collection of data from the authors' direct experience and networks, providing witness or first-hand information. We documented three cases of emergency decompression following bell evacuations, and six cases of accelerated decompression performed in the chamber or hyperbaric rescue chamber. Review of these cases showed: 1) the complicated nature of such emergencies that make decisions difficult; 2) the variety of solutions implemented; and 3) the surprisingly safe and successful outcomes of several operations. Analysis of the accelerated decompression occurrences allowed derivation of the options used; upward initial excursion, increased chamber partial pressure of oxygen associated to increased ascent rates, and inert gas switching. We identified four published procedures for accelerated decompression. Despite modern hyperbaric rescue systems, accelerated decompression remains an essential tool in case of emergency. The diving industry needs clear guidance on what can be achieved, depending on the saturation depth and the level of emergency.

Vascular Function Recovery Following Saturation Diving.

Background and Objectives: Saturation diving is a technique used in commercial diving. Decompression sickness (DCS) was the main concern of saturation safety, but procedures have evolved over the last 50 years and DCS has become a rare event. New needs have evolved to evaluate the diving and decompression stress to improve the flexibility of the operations (minimum interval between dives, optimal oxygen levels, etc.). We monitored this stress in saturation divers during actual operations. Materials and Methods: The monitoring included the detection of vascular gas emboli (VGE) and the changes in the vascular function measured by flow mediated dilatation (FMD) after final decompression to surface. Monitoring was performed onboard a diving support vessel operating in the North Sea at typical storage depths of 120 and 136 msw. A total of 49 divers signed an informed consent form and participated to the study. Data were collected on divers at surface, before the saturation and during the 9 h following the end of the final decompression. Results: VGE were detected in three divers at very low levels (insignificant), confirming the improvements achieved on saturation decompression procedures. As expected, the FMD showed an impairment of vascular function immediately at the end of the saturation in all divers but the divers fully recovered from these vascular changes in the next 9 following hours, regardless of the initial decompression starting depth. Conclusion: These changes suggest an oxidative/inflammatory dimension to the diving/decompression stress during saturation that will require further monitoring investigations even if the vascular impairement is found to recover fast.

Remotely Operated Vehicle Taxonomy and Emerging Methods of Inspection, Maintenance, and Repair Operations: An Overview and Outlook

Abstract Remotely operated vehicle (ROV)-based inspection, maintenance, and repairs (IMR) services are costly because operations are traditionally executed by a hired subsea contractor, who then hires a specialized vessel with an entire crew from the vessel owner or the shipping company. Even though this is an established method considered relatively reliable in comparison to human divers, there is a growing need for more versatile, efficient, and economical IMR methods. Innovations that require no or less use of support vessels are mitigating this challenge. The current ROV classifications do not adapt to these innovations. Hence, the lack of a widely accepted ROV classification. Thus, this paper reviews ROV classifications and proposes a classification that poses no hindrance to innovation and conforms to modern developments. The paper then illustrates and reviews the emerging methods of conducting IMR operations by putting together in a concise, yet resourceful manner the ROV technologies and their various configurations to provide a basic meaningful understanding to the audience. This paper also provides a summary of the comparison of the methods and some of their challenges.

Development and Field Testing of a Smart Support System for ROV Operators

The article considers the issues of development of a smart system for supporting activities of ROV operators and its practical implementation for the efficient operation a ROV Comanche 18 that is based on the R/V Akademik M.A. Lavrentiev. The system uses algorithms that provide coordinated movements of the ROV and its depressor unit. These algorithms are designed for ROVs to make synchronous, accurate, and accident-free movements along long-distance routes even when launched from a support vessel without dynamic positioning (DP). For this, the operator receives real-time visual recommendations and warnings generated on the basis of the expert evaluation of information coming from various sensors and positioning systems. The ability to plan routes of the ROV and its mothership, inputting target points, saving maps, tracks, and locations of the detected underwater objects are also implemented in the designed system. The article presents the results of successful tests carried out during a deep-sea research expedition of the A.V. Zhirmunsky National Scientific Center of Marine Biology FEB RAS in the Bering Sea and Pacific Ocean. The created smart support system for ROV operators significantly extends the range of capabilities of ROVs performing many unique underwater operations, while significantly reducing their operating time.

Climate-Resilient and Eco-Friendly Shipping: Mapping the Trends

Abstract A climate-resilient and eco-friendly maritime transport is the key to sustainable development. In response to the Paris Climate Accord, the International Maritime Organization has adopted strategies to reduce greenhouse gas emissions from ships by ~50% by 2050, compared to levels reported in 2008. The article reviews the ongoing efforts toward achieving clean, safe, and efficient marine transport. The transformation pathway requires sustained innovation, investment, and policy support in economic production and reliable supply for ammonia and hydrogen fuels, battery-based hybrid power systems for support vessels, artificial intelligence-enabled autonomous ships, energy-efficient and low-noise ship design, and improved operational planning.

Concurrent 10. Presentation for: Honey, I shrunk the boat? Uncrewed subsea inspections leveraging remote operations technology

Presented on Wednesday 18 May: Session 10 Between May and November 2021, Woodside, in collaboration with Fugro, completed multiple, world-first, fully uncrewed inspection campaigns of trunklines and subsea infrastructure in the North West Shelf, all utilising a surface vessel and underwater robot (ROV), remotely operated via beyond-line-of-sight satellite communications architecture. Similar work is traditionally performed by a Multipurpose Support Vessel (MPSV) with >50 people onboard, consuming >20 m3/day fuel during transits. Transition to uncrewed remote operations technology has enabled the use of a much smaller (12 m) vessel, removing health and safety risk associated with offshore crew, and with <0.2 m3/day fuel consumption during transit. High-resolution hull and ROV-mounted multi-beam data, ROV-mounted laser point cloud data, ultra-high-definition images and videos and Cathodic Protection (CP) field gradient data were all successfully collected, and operations were completed from the busy Dampier Port with no incidents. Delivery of this landmark achievement was enabled by a multi-year staged technology plan in collaboration with Woodside’s subsea Inspection, Maintenance and Repair (IMR) contractor, Fugro, including establishment of a dedicated remote operations centre based at International Communications Facility. Extensive stakeholder engagement was performed internally and with external regulatory bodies to ensure that all risks were captured, understood and managed so that all parties were aligned on implementation of the novel approach. Application of this technology is forecast to transform the costs of IMR operations vs traditional methods, effectively eliminate carbon emissions and offshore personnel exposure hours, and create opportunities for a more diverse workforce in the sector. To access the presentation click the link on the right. To read the full paper click here

Energy Efficiency of Offshore Support Vessels

The International Maritime Organization has brought forward the need to reduce CO2 emissions from ships. There have been many deliberations in this regard; however, there is an absence of specific guidelines to monitor emissions in offshore support vessels. This study attempts to prioritize the various factors affecting the operational energy efficiency of these vessels. The objective of this study is to rank the factors and sub-factors based on feedback from various stakeholders. Three major factors namely Managerial, functional and Infrastructural and their respective sub factors were considered for the study. In total, seventeen sub-factors were taken for the study and feedback from twenty-two stakeholders were obtained. The Best worst method, which is an MCDM approach, is deployed to rank these factors based on feedback from various stakeholders. Infrastructure factors emerge as the leading factors among the three major factors: vessel performance monitoring, digitalized fleet management, and regulatory compliance. The study throws light for vessel operators to focus on infrastructure sub-factors for better energy efficiency in offshore vessels.

An Arm-Claw-Type Manipulator for Rapid Deep Water Salvage with a General Support Vessel, Part A: Prototype and Test

This paper proposed a concept prototype of the arm-claw-type manipulator with a general purpose support vessel for the rapid salvage of deep submergence vehicles, aircraft, satellites, etc. The key functions were realized, including object clamping, claw butting and locking, position and posture adjustment, awareness, positioning, and navigation. The prototype was successfully tested in a lake environment on a hollow and cylindrical object. The arm-claw-type manipulator is suitable for the rapid salvage of cylindrical objects in an underwater environment to minimize the clamping force and possible clamping damage on the object being salvaged. Four propeller thrusters with a symmetrical arrangement can be used for the adjustment of position and posture in underwater environments, to match the orientation of the object. Cameras capture the profile images of the underwater salvage object and can be used for posture adjustment, but in dark, deep-water environments, sonar can be used in the place of underwater cameras.

Honey, I shrunk the boat? Uncrewed subsea inspections leveraging remote operations technology

Between May and November 2021, Woodside, in collaboration with Fugro, completed multiple, world-first, fully uncrewed inspection campaigns of trunklines and subsea infrastructure in the North West Shelf, all utilising a surface vessel and underwater robot (ROV), remotely operated via beyond-line-of-sight satellite communications architecture. Similar work is traditionally performed by a Multipurpose Support Vessel (MPSV) with >50 people onboard, consuming >20 m3/day fuel during transits. Transition to uncrewed remote operations technology has enabled the use of a much smaller (12 m) vessel, removing health and safety risk associated with offshore crew, and with <0.2 m3/day fuel consumption during transit. High-resolution hull and ROV-mounted multi-beam data, ROV-mounted laser point cloud data, ultra-high-definition images and videos and Cathodic Protection (CP) field gradient data were all successfully collected, and operations were completed from the busy Dampier Port with no incidents. Delivery of this landmark achievement was enabled by a multi-year staged technology plan in collaboration with Woodside’s subsea Inspection, Maintenance and Repair (IMR) contractor, Fugro, including establishment of a dedicated remote operations centre based at International Communications Facility. Extensive stakeholder engagement was performed internally and with external regulatory bodies to ensure that all risks were captured, understood and managed so that all parties were aligned on implementation of the novel approach. Application of this technology is forecast to transform the costs of IMR operations vs traditional methods, effectively eliminate carbon emissions and offshore personnel exposure hours, and create opportunities for a more diverse workforce in the sector.