Supply Vessel Research Articles

Comparative Analysis of Marine Alternative Fuels for Offshore Supply Vessels

This paper provides an in-depth analysis of alternative fuels, including liquefied natural gas (LNG), hydrogen, ammonia, and biofuels, assessing their feasibility based on operational requirements, availability, safety concerns, and the infrastructure needed for large-scale adoption. Moreover, it examines hybrid and fully electric propulsion systems, considering advancements in battery technology and the integration of renewable energy sources, such as wind and solar power, to further reduce SOV emissions. Key findings from this research indicate that LNG serves as a viable short- to medium-term solution for reducing GHG emissions in the SOV sector, due to its relatively lower carbon content compared to MDO and HFO. This paper finally insists that while LNG presents an immediate opportunity for emission reduction in the SOV sector, a combination of hydrogen, ammonia, and hybrid propulsion systems will be necessary to meet long-term decarbonisation goals. The findings underscore the importance of coordinated industry efforts, technological innovation, and supportive regulatory frameworks to overcome the technical, economic, and infrastructural challenges associated with decarbonising the maritime industry.

Is the Sublingual Artery a Reliable Alternative for Intraoral Anastomoses in Head and Neck Free-Flap Reconstruction? Anatomical Basis and Preliminary Results

Background/Objectives: Head and neck free-flap reconstructions are often required to treat tumors or extensive post-traumatic jaw defects. The facial artery is the standard receiving vessel for intraoral microvascular anastomoses. However, its use is associated with several disadvantages, such as lesions of buccal nerve branches of the facial nerve or the parotid duct, as well as variability in course and diameter. The aim of this study is to investigate whether branches of the sublingual artery can be considered as an alternative intraoral supply vessel to the facial artery to avoid these drawbacks. Methods: Twelve formalin-fixed cadaveric heads with 24 sides (n = 24) were dissected. The origin, course, branching pattern, and distribution of the sublingual artery were examined. In addition, the diameters of the branches of the sublingual artery were assessed to identify potential supply vessels for anastomoses. Results: In ten of the twenty-four cases (41.7%), the sublingual artery originated from the lingual artery, and in nine cases (37.5%), the lingual artery originated from the facial artery. The main trunk of the sublingual artery was present in the floor of the mouth in all cases (100%), with a diameter of ≥0.9 mm in vitro (1 mm in vivo). In 15 of the 24 half heads (62.5%), branches of the sublingual artery with ≥0.9 mm were identified in this space, with the main branch being considerably stronger. Conclusions: The large diameter of the sublingual artery in the floor of the mandible suggests that this vessel or its branches could be considered as alternative pedicles for intraoral anastomoses in mandibular microvascular free-flap grafts.

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.

Pulmonary sequestration associated with pulmonary actinomycosis: A case report and literature review.

Pulmonary sequestration (PS), a rare pulmonary disease, arises from congenital pulmonary vascular dysplasia. Meanwhile, pulmonary actinomycosis is a purulent infection of lung lesions triggered by the inhalation of actinomycetes, which is also uncommon. Even rarer is the occurrence of pulmonary actinomycete infection secondary to PS. Herein, we present a case report of such a rare occurrence. The 21-year-old female patient had been erroneously diagnosed with pneumonia and tuberculosis, presenting symptoms of cough, sputum, and hemoptysis; however, the implemented anti-infection and antituberculosis treatments proved to be ineffective. The diagnosis of the sequestration in the right lower lung was confirmed through an enhanced chest CT scan and a 3-dimensional reconstruction of the pulmonary vessels. During the surgical video-assisted thoracoscopic resection of the right lower lobe lesion, it was discovered that the isolated lung tissue's blood supply vessel originated from the thoracic aorta. Additionally, the pathological examination revealed that the lung tissue of the right lower lobe lesion was infected with pulmonary actinomycetes. Following thorough evaluation, the patient received a final diagnosis of pulmonary actinomycete infection that occurred secondary to right lower lung sequestration. Consequently, they underwent treatment consisting of high-dose penicillin administered for a period of 6 months post-operation. Over the course of the subsequent 23-month follow-up, no recurrence of the infection or abnormal CT scan findings were observed. Pulmonary sequestration bears clinical resemblance to pulmonary actinomycetes. In cases where recurrent episodes of pneumonia occur at the same location, and chest imaging indicates persistent lesions in the basal segment of the lower lobe near the spine, the possibility of PS should be considered. Prompt chest-enhanced CT and 3-dimensional reconstruction of pulmonary vessels are crucial for a definitive diagnosis. Imaging findings such as mass-like consolidation, cystic lesions, liquefactive necrosis, and pneumonia-like changes, coupled with typical air suspension signs and sulfur-like particles visible under tracheoscopy, suggest a potential pulmonary actinomycete infection. Timely biopsy is essential to confirm the diagnosis and prevent missed or incorrect diagnoses.

Theory and practice on mesentery margin in vessel-oriented complete mesentery resection of gastric cancer

The concept of mesenteric anatomy has been evolving in cognition. With the continuous development of endoscopic techniques, the submicroscopic structures of many mesenteries have been gradually understood, ultimately confirming the ubiquitous presence of mesenteries in the digestive organs. Based on various domestic and foreign mesenteric anatomical theories and combined with years of clinical practice, we have summarized and proposed a new concept and theory-vascular-guided complete mesenteric resection for gastric cancer. The theoretical basis is that, from the perspective of the embryonic development of the digestive tract, the rotation of the digestive tract and its associated mesentery is always centered on blood vessels. Therefore, the supply vessels and digestive tracts and their associated mesentery are naturally connected. The mesentery is a complex structure that encompasses blood vessels, nerves, and lymphatic tissues. The blood vessels serve as the boundary of the mesentery, ensuring that the lymphatic network that drains the tumor is maximally resected. This article focuses on the complete mesenteric resection margins in gastric cancer surgery, that is, the lateral boundary of the mesentery as the vascular-supplied guided resection boundary and its mesentery, and the base boundary as the mesenteric bed. Using precise vascular guidance to define the extent of mesenteric resection will help accurately define the mesenteric margin during radical resection for different stages of gastric cancer.

Risk assessment of general FPSO supply system based on hybrid fuzzy fault tree and Bayesian network

One of the major risks to the operation of a FPSO (Floating, Production, Storage and Offloading) is collision of supply vessels. Experiences have shown that collisons of supply vessel take place frequently, although the consequences are limited. The offshore oil&gas industry has established relevant design standards and operational procedures, which are proven to be effective in reducing this risk. As the risk assessment becomes increasingly applied, there is a need to quantify the likelihood of supply vessel collisions especially duing the early design/project stage when historical incident data does not exist. This paper proposees a method for estimating the likelihood of supply vessel collision based on fault tree analysis (FTA), Bayesian network (BN), hybrid theory and fuzzy theory. In liew of using historicval data, this method combines the fuzzy logic with expert heuristics to determine the basic events(BEs). The triangular fuzzy membership functions and a hybrid theory were adopted to define factors that lack data or had no data in the events. To account for the imprecise information of human error, a scheme is devised to use the fuzzy fault probability(FFP) based on the hybrid theory, or a hybrid fuzzy fault tree analysis (HFFT). The algorithm transforms the FT into a BN with a conditional probability table (CPT). This new method was demonstrated in an example of a FPSO, and the results were has been validated through case studies and accident reports. A sensitivity analysis was also conducted to illustrate key parameters.

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.

Collision between supply vessels and offshore installations case cargo handling and personal transferring operation

Abstract This paper presents a systematic methodology aiming at investigating human-error induced collisions between attendant vessels and offshore installations, with focus on three key risk categories: Cargo handling and personnel transferring (CH), loss of station keeping (SK) and ship handling and maneuvers (SH). Because of space limitation, the methodology will be applied here to the first category (CH) only. The Failure Mode, Effects and Criticality Analysis (FMECA) method was used to identify the hazards. Moreover, the Interpretive Structural Modeling (ISM) of Multi Criteria Decision Making (MCDM) was used for the same purpose and results of both methods were favorably compared. Moreover the Fault Tree Analysis (FTA) was used to evaluate the root causes of accidents down to the Underling Factors (UFs) benefiting from the revised guidelines for the IMO Formal Safety Assessment (FSA).

Gasless transoral endoscopic thyroidectomy in a primary substernal goitre patient: First case.

For most primary substernal goitre (SG) surgeries, sternotomy is required because the blood supply vessels of tumours come from the mediastinum. However, sternal dehiscence may lead to several surgical complications. We reported an older patient who underwent simultaneous removal of a primary SG and parathyroid adenoma through a gasless transoral endoscopic approach. The patient recovered well with no hoarseness, post-operative bleeding or other complications after the operation. To the best of our knowledge, this is the first reported case of gasless transoral endoscopic parathyroid adenoma and primary SG resection in the real world. We found that gasless transoral endoscopic surgery is feasible in patients with small primary SG and parathyroid adenoma.

Port State Control of Offshore Supply Ships, MODU and FPSO Units

The Port State Control system aims to ensure that all ships are subject to regular inspections, with particular attention to the ships of insufficient quality. To this end, during the inspection, priority is given to ships that are considered risky. Thetis database is an information system that contributes to the implementation of the Port State Control within the EU (European Unit). It contains data on inspections performed in the EU ports and the Paris Memorandum area. The Paris Memorandum has 27 member states and covers the waters of European coastal states and the North Atlantic basin from North America to Europe. The main goal of the Paris MoU (Memorandum of Understanding) is to eliminate substandard ships through a harmonized Port State Control system. Namely, inspections should ensure that ships meet international safety standards, are safe for the environment, and provide adequate living and working conditions for workers. The primary responsibility for ensuring these standards rests with the ship owner/shipper while the responsibility for ensuring such compliance rests with the flag state. The aim of this analysis is to determine the number of inspections performed in the ports of the Republic of Croatia and the Republic of Italy, to identify the cause of ship detentions and the most common deficiencies of offshore supply vessels, MODU (Mobile Offshore Drilling Units) and FPSO (Floating Production Storage and Offloading) Units. In the observed period, the impact of the crisis caused by the COVID-19 pandemic was significant, resulting in the decline in the numbers of inspections performed in 2020 and 2021. In 2022, the number of inspections increased, but it still has not reached its pre-pandemic level. During the period that was the subject of research, port state inspections in the Republic of Croatia and the Republic of Italy revealed 241 deficiencies. Five areas with the largest number of deficiencies are: Certificate & Documentation, Safety of Navigation, Fire Safety, ISM, and Life-saving appliances, which follow the trend of the lack in the areas of the Paris Memorandum. The greatest increase in deficiencies was recorded in the areas of Labor Conditions-Health protection, Certificate & Documents (Crew Certificate, Documents), Emergency System and Fire safety area, which led to an increase in the number of offshore supply ships retention during the first half of 2022.

Implementation of Kaplan Type Ducted Propeller on Hydrodynamics of Offshore Supply Vessel (OSV)

Implementation of Kaplan Type Ducted Propeller on Hydrodynamics of Offshore Supply Vessel (OSV)

All Aboard the Nascopie: Image-Making, Colonial Modernity, and Coastal Memory in the Canadian Eastern Arctic

Between 1912 and 1947, when it sank, the icebreaker the RMS Nascopie, a British-made vessel commissioned by the HBC to be used as a supply ship, serviced the eastern Canadian Arctic. For an eight-year period during this time it also counted tourists among its passengers, alongside HBC personnel, missionaries, medical practitioners, scientists, and government officials. Life aboard the ship, wildlife, sea ice, inclement weather, and Inuit were all documented in the reports, written diaries, and visual records that emanated from the Nascopie as it operated under the many, often contradictory, guises of icebreaker, supply vessel, cruise ship, and sovereign symbol. Looking across photography, painting, and printmaking during the 1930s through to the present day, I consider the Nascopie as an anchor between the visual arts and the coastal landscape. Here, I position Inuit and non-Inuit perceptions of cultural and environmental change and continuity along Canada’s coastline within the transformative effect of colonial modernity. Image-making, notably photography and painting, aboard the Nascopie sought to reproduce the Canadian Arctic as an object of collective history and national identity. Confronting the often-anonymous Inuit and Arctic environments throughout the photography and painting of Lorene Squire and F.H. Varley, I identify how the Nascopie, as a colonial actor in the local landscape, persists in contemporary Inuit visual and cultural memory, most notably in the work of Shuvinai Ashoona. By untangling the inter-media and multi-temporal role of the Nascopie across past and present image cultures, I explore the intertwined narratives of coastal history, visual culture, and colonial modernity in the eastern Canadian Arctic.

Composite anti-disturbance dynamic positioning for mass-switched unmanned marine vehicles with multisource disturbances and actuator saturation: A switched model method

This article focuses on the composite anti-disturbance dynamic positioning (CADDP) control problem for the unmanned marine vehicle (UMV) system subject to mass switching, multisource disturbances and actuator saturation. The multisource disturbances include the unmeasurable modeled disturbances and measurable unmodeled disturbances. First, a switched model is introduced to describe the mass-switched UMV (MSUMV) system. Then, a series of switching observers are built to capture the unmeasurable disturbances. Meanwhile, the convex hull technique is exploited to address the actuator saturation. Further, based on the disturbance observer, the CADDP control scheme is developed to alleviate the influences of the multisource disturbances and actuator saturation, and to achieve the dynamic positioning (DP) of the MSUMV model. In the end, the established CADDP control strategy is carried on a supply vessel to illustrate the feasibility of the developed theory.

Automated machine learning driven model for predicting platform supply vessel freight market

Platform Supply Vessels (PSVs) play an essential role in supporting oil and gas platforms, and other offshore structures by transporting crew members, personnel, provisions, and further indispensable equipment from onshore to operational sites. PSV freight rate movements are subject to a complex array of non-linear interconnected influential factors. Reviewed literature reveals an absence of forecasting studies predicting PSV freight rates. Meanwhile, Automated Machine Learning (AutoML) frameworks have never before been employed to forecast maritime freight rates. Therefore, this study investigates factors influencing PSV time charter freight rates and explores AutoML modelling in capturing non-linearities while forecasting PSV freight rates over a 1, 3 and 6-month out-of-sample forecast horizon. A total of 43 relevant factors are included in prediction modelling, the most comprehensive number of explanatory variables in the shipping forecasting literature to date. The data consists of 188 monthly observations collected from two databases: Clarksons Shipping Intelligence Network and Offshore Intelligence Network. Time-lagged variables are utilized as data of explanatory variables are not immediately available at the time of forecasting. A total of 79 complex machine learning models are tested, and the best-performing models are Eureqa Generalized Additive Model, eXtreme Gradient Boosted Trees Regressor, and Ridge Regressor with Forecast Distance Modelling, benchmarked against the proven statistical forecasting model triple exponential smoothing. The most influential factors are historical PSV time charter freight rates, newbuilding prices, number of vessel deliveries, orderbook number, total vessel sales, and the unique variable number of active drilling rigs in the market.

Motion-Based Wave Inference With Neural Networks: Transfer Learning From Numerical Simulation to Experimental Data

Abstract The directional wave spectrum, which describes the distribution of wave energy along frequencies and directions, can be estimated from the measured motions of a vessel subjected to a particular sea condition by resorting to the wave-buoy analogy. Several methods have been proposed to address the inverse estimation problem; recently, machine learning techniques have been assessed as further alternatives. However, it may be difficult to gather large datasets of in-service motion responses and the associated sea states to train effective data-driven models. In this work, an encoder–decoder neural network is trained with the synthetic responses of a station-keeping platform supply vessel (PSV) to estimate the directional wave spectrum. This estimation model is directly applied to perform wave inference from motion data of wave basin tests with a small-scale model of the same vessel. Furthermore, fine-tuning is also used to incorporate experimental data into the neural network model. Results show a satisfactory match between estimated and measured values, both with respect to the energy distribution and the integral spectrum parameters, indicating that the proposed approach can be employed to obtain data-driven wave inference models when there is little or no availability of measured motion records and the corresponding sea conditions.

Nonlinear Model Predictive Control for a Dynamic Positioning Ship Based on the Laguerre Function

In this paper, we present a novel nonlinear model predictive control (NMPC) algorithm based on the Laguerre function for dynamic positioning ships to solve the problems of input saturation, unknown time-varying disturbances, and heavy computation. The nonlinear model of a dynamic positioning ship is presented as a linear model, transformed from a standard affine nonlinear state-space model by precise feedback linearization. The environmental disturbance is overcome using an integrator. The time cost of the proposed nonlinear control algorithm is decreased by inducing the Laguerre function to describe the feedback-linearization system input increments. The Laguerre function reduces the matrix dimensions of the nonlinear optimization problem. The simulation results for a DP supply vessel showed that the novel algorithm maintained the effective control performance of the original nonlinear model predictive control algorithm and had a reduced computation load to satisfy the requirements of real-time operation.

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.

Routing and scheduling of platform supply vessels in offshore oil and gas logistics

In this work, we focus on an operational logistics problem that arises in the offshore oil and gas exploration and production industry. In particular, we aim to design cost-effective routes and schedules for platform supply vessels, which are routinely employed to deliver necessary supplies to the platforms as well as to collect from those platforms used materials that need to be transported back to the onshore base for maintenance, reuse, or discarding. To address the rich-featured routing problem that arises in this offshore logistics application, we introduce a novel mixed-integer linear programming formulation and propose a specialized branch-and-cut algorithm to solve such a model. Furthermore, in order to evaluate our proposed algorithm’s performance, we conduct an extensive computational study using representative benchmark instances inspired by real operational data. The computational results show that our algorithm solved the majority of those instances to optimality, demonstrating its potential for practical use in offshore oil and gas logistics operations.

Composite Anti-Disturbance Dynamic Positioning for Mass-Switched Unmanned Marine Vehicles

This article presents a composite anti-disturbance dynamic positioning (CADDP) control technique for a mass-switched unmanned marine vehicle (MSUMV) subject to the influence of wave drifts and residual filtered wave. The wave drifts and residual filtered wave are described as unmeasurable modeled disturbances and measurable unmodeled disturbances, respectively. Then, the UMV with mass switching is modeled as a switched system. Further, by virtue of the multiple Lyapunov functions technique, DP of the UMV is achieved with composite disturbance rejection capability. The effectiveness of the presented method is illustrated by simulations with a supply vessel.

Ultrasonographic Study of the Corkscrew Arterial Image in Buerger Disease Patients.

Objective: Thromboangiitis obliterans (Buerger disease) is known as an intractable vascular disease that has been reported as thrombosis in distal arteries and occasional venous occlusion, as well as inflammatory changes in the thrombus and vascular wall. Patients often require limb amputation due to limb necrosis. Corkscrew (CS), a small arterial coiling, is an important diagnostic finding that was mainly found with angiography. Recently, however, it can also be identified using a modern ultrasonographic technique. Methods: In these 22 cases, in 48 areas of study, we used the ultrasonographic technique to identify the CS, which allowed us to observe its relationship with the surrounding nerves and arteries. Results: In all cases, it was possible to identify the CS easily and it was confirmed that the CS and the nerve were carried down in their sheath. The sites of the CS existed in areas other than the area around the occluded main arteries and some CS that ran inside the nerve (16 areas) and some CS that accompanied the outside of the nerve (10 areas) were confirmed, suggesting the CS work as collateral blood supply vessels, with well-developed normal vessel-like anatomy. Conclusion: When we observe the CS, it is important to observe not only around the main trunk artery but also areas where nerves mainly run, even if they do not accompany the main trunk artery. (This is a translation of Jpn J Vasc Surg 2023; 32: 345-350.).