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Port congestion caused by ship detention is an important reason for the obstruction of the shipping supply chain. In this paper, a method of excavating the ship waiting behavior outside the port is proposed based on the automatic identification system (AIS) data and considering uncontrollable factors. Firstly, combined with the analysis of ship navigation behavior, the speed threshold of the ship waiting outside the port is defined through average speed. Secondly, the range of ships berthing in the port is distinguished, and the different waiting behavior of ships are clarified. Finally, the situation of different types and sizes of ships waiting outside the port is analyzed. The paper found that ships of different types and sizes have distinctive clustered waiting behavior, and there are significant differences in waiting time. At the ship type, bulk cargo ship have the highest number among ships waiting outside the port, followed by tanker and container ship; at the ship scale, basically, the number of ships waiting outside the port decreases with the increase of the scale, but the average waiting time is longer. It has an excellent practical promotion value for the application of AIS data and development of shipping. [ABSTRACT FROM AUTHOR]

Despite a general agreement that piracy poses a significant threat to maritime shipping, empirical evidence regarding its economic consequences remains scarce. This paper combines firm-level Chinese customs data and ship position data with information on pirate attacks to investigate how exporting firms and cargo ships respond to maritime piracy. It finds that overall exports along affected shipping routes fall following an increase in pirate activity. In addition, piracy induces firms to switch from ocean to air shipping, while remaining ocean shipments become larger. At the ship-level, the paper provides evidence for re-routing, as container ships avoid regions prone to pirate attacks. [ABSTRACT FROM AUTHOR]

The operational problem of container unloading from the ship is analyzed in this paper. Dynamic “crane-cargo-ship” system was investigated, and a mathematical model was created. In the model, the gap between the container and the ship’s cargo hold, the mass of the cargo, the container’s center of the mass, and the frictional forces that may occur during lifting from the cargo hold were estimated. Numerical analysis of the system was performed. Results of numerical analysis were compared with experimental measurements of containers unloading process in port. Requirement of lifting power was modelled depending on mass of cargo. Additional power needs in case of contact forces between container and wall of the ship’s cargo hold were calculated. Rational lifting conditions could be deduced using a created mathematical model and the reliability of the container and cargo during lifting could be deduced. [ABSTRACT FROM AUTHOR]

This paper introduces a scenario evolution model for maritime accidents, wherein Bayesian networks (BNs) were employed to predict the most probable causes of distinct types of maritime incidents. The BN nodes encompass factors such as accident type, life loss contingency, accident severity, quarter and time period of the accident, and type and gross tonnage of the involved ships. An analysis of 5660 global maritime accidents spanning the years 2005 to 2020 was conducted. Using Netica software, a tree augmented network (TAN) model was constructed, thus accounting for interdependencies among risk-influencing factors. To confirm these results, a validation process involving sensitivity analysis and historical accident records was performed. Following this, both forward causal inference and reverse diagnostic inference were carried out on each node variable to scrutinize the accident development trend and evolution process under preset conditions. The findings suggest that the model was competent in effectively predicting the likelihood of various accident scenarios under specific conditions, as well as extrapolating accident consequences. Forward causal reasoning unveiled that general cargo ships with a gross tonnage of 1–18,500 t were most prone to experiencing collision and stranding/grounding accidents in the first quarter. Reverse diagnostic reasoning indicated that, in the early morning hours, container ships, general cargo ships, and chemical ships with a tonnage of 1–18,500 t were less likely to involve life loss in the event of collision accidents. [ABSTRACT FROM AUTHOR]

• We use language models to construct sentiment indices for the shipping market. • Similar to the stock market, shipping market sentiment also has a reversal phenomenon. • Shipping market sentiment is an important factor for pricing other than fundamentals. • Shipping sentiment indices eliminate the reverse causal relationship with market prices. • Language models significantly outperform the lexicon-based approaches for sentiment analysis. This paper applies language models to the shipping market for the first time and studies the impact of changes in shipping market sentiment on freight rates. First, based on language models and Clarksons' commentary reports, this paper proposes the sentiment indices for the entire shipping market and the sub-markets for bulk ships, tankers, and container ships. Second, empirical results indicate that, apart from the container shipping market sentiment index, all other shipping sentiment indices including the total shipping market sentiment index, the dry bulk shipping market sentiment index and the tanker shipping market sentiment index serve as positive predictive indicators for shipping freight rate indices. Third, this paper investigates the interaction between the shipping sentiment index and market prices through a vector autoregressive model and the Granger causality test. We find that the total shipping market sentiment index is the Granger cause of the Baltic Dry Index and the Baltic Dirty Tanker Index. The dry bulk shipping market sentiment index and the container shipping market sentiment index are the Granger causes of the Baltic Dry Index and the China Containerized Freight Index, respectively. Last, this paper compares the shipping sentiment index constructed by market-specific language models and lexicon-based sentiment analysis. It is evident that language models significantly outperform the lexicon-based approaches for sentiment analysis and are expected to be useful for analyzing textual sentiment in the field of asset pricing research. [ABSTRACT FROM AUTHOR]

Most of the research on ship rolling motion concerns a specific type of ship, such as containerships, or analyzes sailing during certain wave characteristics, rather than the full spectrum of waves that can be encountered during the entire sea route. To date, the most frequent merchant ships in the world are general cargo ships, where the ship's behaviour at any sea condition has a great influence on overall safety, as well as the lashing design of non-standardized cargo. For this reason, the present paper aimed to study ship-performance models, starting with concepts of the basic physics of ships and waves. Firstly, the ship's behaviour was analyzed from a theoretical point of view, both in calm waters and when sailing in waves, but independently. Afterwards, the ship-waves system was analyzed during rolling with all variables accounted for at the same moment, with the objective of obtaining roughly realistic models. Relevant results are shown in each of the models, which may be of great interest for ship operators and, in general, for the shipping industry, so as to improve the safety of maritime transport. Finally, these results were validated with a case study. [ABSTRACT FROM AUTHOR]

• Ice thickness, ice conditions, and ice class directly affect shipping costs. • Ice conditions are softening, decreasing the expected NSR fee level. • Ships of some ice-classes can sail within the NSR independently. • Ships without ice protection are unprofitable for shipping in the NSR. • The NSR icebreaker escort fee may be several times lower than the SCR toll. Even though the Arctic ice is melting and Polar routes are being extensively studied, the amount of cargo shipped through the Northern Sea Route (NSR) remains low. Employing current data on the NSR operation provided by China Ocean Shipping Company, this paper investigates annual profitability of the NSR-SCR combined use, when a vessel sails through the NSR in summer and the SCR in winter. A Handysize general cargo ship is used as a model vessel since it allows reaching nearly maximum load rate and can sail through shallow areas of the NSR. This article proposes including ice thickness and ice conditions in the traditional cost comparison. The first parameter directly affects sailing speed, and hence other cost variables, while the second one is included in the official NSR navigation rules and connected with icebreaker escort fee. This paper also contributes to the existing literature by considering total shipping cost as a function of a vessel's ice class with corresponding building premiums and fuel consumption increments. The proposed approach is easily replicable, so shipping companies might use it to rethink their positions on shipping through the NSR. The overall conservative comparison reveals that the NSR-SCR combined shipping scheme can only be more competitive than sailing through the SCR if a shipping company provides a sufficient load rate on the NSR leg and uses a ship of a reliable ice class to navigate throughout the summer navigation. The NSR-SCR combined shipping scheme becomes attractive if the NSR leg is short, and the crude oil price is high. [ABSTRACT FROM AUTHOR]

In recent years, the Northeast Passage (NEP) has been widely discussed in the shipping industries since it can potentially bring economic benefit thanks to its relatively short sailing distance vis-a-vis the conventional Asia-Europe route via the Suez Canal. Concomitantly, due to the recent advocacy of green shipping, how to deploy effectively a shipping fleet so as to reduce the environmental cost has become an increasingly crucial issue in the shipping industries. However, it has not been investigated how the optimal shipping allocation between the conventional Asia-Europe route and NEP, based on both economic and environmental considerations, will be influenced by different aspects of shipping costs respectively, which will further affect the ocean carriers' decision and adoption attitude toward the NEP. In this paper, a quantitative assessment model considering the shipment operating cost as well as the external cost of various pollutant emissions is presented to analyze the multi-port multi-trip liner service in an Asia-Europe container shipping network. Based on the shipping network with cargo demand of an Asian shipping company and empirical data from the existing literature, our study demonstrates how the optimal shipping allocation varies between scenarios by performing sensitivity analyses. Our findings indicate that the icebreaker fee, as well as Suez Canal toll, plays a more decisive role than the fuel price in affecting the adoption of the NEP. The relevant policy and managerial implications are discussed. [ABSTRACT FROM AUTHOR]

The paper presents the results of an experiment conducted on two cargo ships – a 5300 TEU container with a steam heating system and a 7500 dwt general cargo ship with a thermal oil system. On both ships research has been carried out using specially designed measuring equipment. After gathering data about flow velocity and temperatures (steam/ cooling water/ thermal oil/ seawater/ outside air), calculations have been done, resulting in histograms. For both types of histograms (heat demand and service time), the probability density function was fitted, using the K-S statistical test. The last step was comparison of the probability distribution mean to seawater and the outside air temperatures by linear regression and the coefficient of determination. The dependencies between the mentioned temperatures and heat demand were noted. [ABSTRACT FROM AUTHOR]

In recently constructed vessels, minimization of engine room volume is required to maximize the volume of cargo to be shipped. Therefore, the main engine and the stern bulkhead mounted on the ship are installed as far as possible in the aftward direction. As a result, the length of the propeller shaft is reduced, along with the stern tube bearing span used to support it. In this case, the shaft flexibility is reduced, the reaction influence number is increased, and the point load of each bearing is easily influenced by change in displacement. Because the point load of each bearing is susceptible to hull deformation and thermal expansion, it is difficult to adjust the shaft arrangement and the bearing load change after large adjustment of the shaft arrangement. Therefore, in the past, the bearing was arranged to support the propeller shaft with two forward and afterward stern tube bearings. However, when the main engine and the stern bulkhead are installed as far aftward as possible to minimize the volume of the engine room, it is necessary to provide shaft flexibility by removing the forward stern tube bearing. As a result, the resonance revolution of the propeller blades during whirling vibration of the propulsion shafting system falls within the range of normal operating revolutions. This means that abnormal wear of the stern tube bearing, damage to the stern tube sealing device, and hull structure vibration may occur due to the whirling vibration. In this paper, the characteristics of shafting alignment and whirling vibration of a ship supporting a propeller shaft with double and single stern tube bearings are compared. Moreover, the changes in shaft flexibility and the characteristics of the whirling vibration of a corresponding shafting system in a 50 K-DWT petroleum product tanker were explored by applying a single stern tube bearing. In addition, the shafting alignment and whirling vibration are determined according to the installation position of the intermediate shaft bearing. A method is suggested for selecting the optimal shafting arrangement by which to secure the shaft flexibility of a ship to which a single stern tube bearing is applied, and to avoid resonance from the whirling vibration. [ABSTRACT FROM AUTHOR]

Deploying containerships with increasing carrying capacities in achieving better capacity utilization has been well-documented. However, ship operators often face the problem in deploying containerships with the right size, especially given the capital-intensive nature of container liner shipping, which would lead to substantial implications if inappropriate ships were used. While studies on optimal ship size exist, focus has mainly been on ship operation cost while its implications on other components, or whether there are adequate demands to load the ship, are often not considered. Moreover, while many studies focus on trunk routes, feeder services, despite its parallel significance in a hub-and-spoke shipping network, are often overlooked. Understanding such deficiency, using intra-Southeast Asian feeder liner services as the case study, this paper has undertaken an investigation in simulating the optimal containership sizes from the perspective of ship operators. Through questionnaire survey and economic modelling, analysis focused on whether the perception of industrial players matches simulated results. This paper should play substantial impacts by enabling ship operators to develop better ship deployment strategies through providing an invaluable insight into the feeder market within this increasingly important region, as well as providing a well-developed methodology for maritime researchers in ship size modelling in other regions with potentially different shipping networks. [ABSTRACT FROM AUTHOR]

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Container transport by sea has almost doubled in the last decade. Accordingly, container ships’ size has increased significantly, and the latest container ships carry up to 24000 Twenty-foot Equivalent Units (TEU). In the near future, the appearance of container ships with a capacity of 25000 TEUs can be expected on the market, because the design is already available. It is known that 10-12% of transported containers contain International Maritime Dangerous Goods (IMDG) cargo. The above stated reasons directly impact the frequency of container ship fires in cargo spaces. According to the Insurance Companies, fires occur on average every two months, and this is a growing problem of container transport by sea. In this paper, 23 fires in the cargo area, either in cargo holds or on deck, were analysed. The analysis results determined the most common causes of fires and have shown that the current fire protection systems on container ships are ineffective. It is unacceptable that firefighting systems’ inefficiency results in the loss of human lives, abandonment of vessels, environmental pollution, and extensive property losses related to cargo and ship structure. Due to all the above, it is necessary to continuously work on new regulatory and technical solutions to improve the fire safety of cargo areas on container ships. [ABSTRACT FROM AUTHOR]

Abstract  This is Part II in a series of papers. Part I (J Mar Sci Technol 13:154–163) deals with an approach employed to construct a simplified FE model using a 3D compartment model available from the beginning of the ship design process. This paper begins by describing the limitations of an analytical approach based on shear warping beam theory for assessing torsional strength. Next, the structural parts of a container ship that have a negligible effect on hull girder bending strength and torsional strength are determined. This is verified by removing these parts from a conventional FE model and comparing the results obtained using this modified model with those yielded by the original model. The fore end part, the aft end part and the deck house are examined. Since these parts have complicated structures and relevant drawings for them are issued later than cargo structure drawings, modeling them exactly can result in a delay in the completion of the full ship FE model. This paper also verifies the validity of the simplified FE model built by applying the method proposed in Part I and comparing the results obtained with it with those given by a conventional full ship FE model. The stresses on hatch coaming top, the maximum diagonal elongations of the hatch coaming, and the maximum hatch corner movements are evaluated to check the validity of the simplified model. [ABSTRACT FROM AUTHOR]

This study has aimed to investigate the impact of individual talent on ship captains' job satisfaction, safety performance, and safety motivation, as well as the function of safety motivation as a mediating variable. A quantitative research approach has been used for this investigation. With a sample of one hundred respondents, the population in the study has consisted of all cargo ship captains, including container ships, general cargo ships, bulk carriers, and tankers whose ships stopped at the Tanjung Perak port of Surabaya, Indonesia. Purposive sampling is a sampling method. This study has used SMART PLS software and Partial Least Square strategy for inferential data analysis. The findings show that job satisfaction, safety performance, and safety motivation are significantly influenced by individual aptitude. Safety motivation affects job satisfaction, but safety motivation has no effect on safety performance. The study has also found out that safety motivation variables can mediate the relationship between individual talent and job satisfaction through safety motivation. However, safety motivation is not able to mediate the relationship between individual aptitude and safety performance. The implication of management is that safety motivation plays an important role for cargo ship captains, besides that job satisfaction is also considered to achieve safety performance. [ABSTRACT FROM AUTHOR]

Modern cargo vessel transport constitutes an important part of global economy; hence it is of paramount importance to develop novel, more efficient reliability methods for cargo ships, especially if onboard recorded data is available. Classic reliability methods, dealing with timeseries, do not have the advantage of dealing efficiently with system high dimensionality and cross-correlation between different dimensions. This study validates novel structural reliability method suitable for multi-dimensional structural systems versus a well-established bivariate statistical method. An example of this reliability study was a chosen container ship subjected to large deck panel stresses during sailing. Risk of losing containers, due to extreme motions is the primary concern for ship cargo transport. Due to non-stationarity and complicated nonlinearities of both waves and ship motions, it is challenging to model such a phenomenon. In the case of extreme motions, the role of nonlinearities dramatically increases, activating effects of second and higher order. Moreover, laboratory tests may also be questioned. Therefore, data measured on actual ships during their voyages in harsh weather provides a unique insight into statistics of ship motions. This study aimed at benchmarking and validation of the state-of-the-art method, which enables extraction of the necessary information about the extreme system dynamics from onboard measured time histories. The method proposed in this study opens up broad possibilities of predicting simply, yet efficiently potential failure or structural damage risks for the nonlinear multi-dimensional cargo vessel dynamic systems as a whole. Note that advocated novel reliability method can be used for a wide range of complex engineering systems, thus not limited to cargo ship only. [ABSTRACT FROM AUTHOR]

This paper indicates the repetition of the formation of alliances of shipping companies exhibiting characteristics of cartelization, i.e. the division of markets, well-known from the late nineteenth and early twentieth centuries. The article analyzes the cause of the emergence of cartels in the nineteenth century, and points out the repetition of the same causes to the formation of alliances regarding sea container carriers as a result of the economic crisis of 2007. [ABSTRACT FROM AUTHOR]

The classification and detection of maritime targets are widely used in shipping navigation and military fields. With the development of spaceborne synthetic aperture radar (SAR) technology, more and more very high-resolution SAR images can be acquired for maritime targets recognition. However, due to the different imaging mechanisms between SAR images and optical images, it is difficult and laborious to interpret SAR images manually. This study uses a modified Alexnet structure to realise maritime targets classification on the Gaofen-3 spaceborne SAR images. The maritime targets dataset (MTD), including boats, cargo ships, container ships, windmills, oil tankers, and iron towers, is conducted. Moreover, the proposed convolution neural networks (CNNs) structure is trained and tested on the MTD. Experimental results show that the model can get an accuracy of 92.10% in classifying the six kinds of targets, and the performance is superior compared with other CNNs and traditional supportive vector machine algorithms. [ABSTRACT FROM AUTHOR]

It is estimated that around 10,000 containers are lost during maritime transportation every year, representing an economic loss to the liner industry. Regulations and norms used to calculate values to secure them to the ship's deck account for static loads only, neglecting more realistic conditions. This paper describes an approach to simulate a two-tier scaled model of a 20-ft ISO freight container and its linking connectors, denominated twist locks, subject to a dynamical load induced by its base. To analyze this problem two methods were employed: a shaking table test and finite-element analysis. Results of this study indicate that the numerical model built to simulate two-tier container stack dynamics is a promising tool for further studies. Moreover, the model is able to predict conditions close to real situations faced by container stacks while stored on deck. [ABSTRACT FROM AUTHOR]

The SIMMAN 2008 workshop was held in Copenhagen, Denmark in April 2008. The purpose of the workshop was to benchmark the prediction capabilities of different ship maneuvering simulation methods including systems- and CFD-based methods through systematic quantitative comparisons and validation against EFD data for tanker (KVLCC), container ship (KCS), and surface combatant (5415) hull form test cases. For the KVLCC test case, two stern shape variants named KVLCC1 and KVLCC2 giving different instability loops were included. Free model test data was compared with systems-based methods and CFD for specified free maneuvers. Some of the systems-based methods used provided PMM and CMT data, and two used CFD instead. CFD-based methods were used to simulate forced motions and were compared with PMM/CMT model test data. The submissions were blind in the sense that the benchmark model test data was not provided prior to the workshop, unless data was required as input to the simulation method. A total of 64 submissions were received for the free maneuver simulations, which included a wide range of the state-of-the-art methods in use today, such as PMM- and CMT-based methods, CFD-based methods, system identification, neural network tools and various empirical methods. For the forced motion simulations a total of 16 submissions were received, comprising different CFD-based methods such as RANS, URANS, and DES. This paper gives an overview of hulls, model tests, test cases, submissions, comparison results as well as the most important observations and conclusions. [ABSTRACT FROM AUTHOR]

Although there are some studies on the impact of Sulphur 2020 on shipping in the literature, large-scale economic analyses are scarce. For this reason, in compliance with sulphur abatement, this study aims to determine the most economical alternatives for shipping companies. First, real data are collected from the maritime industry and scenarios are created regarding different ship types, engine powers, sailing times and fuel prices. In conclusion, using very low sulphur fuel oil alternative for dry cargo ships, hybrid scrubber alternative for crude oil tankers, open-loop scrubber alternative for container ships and hybrid scrubber for Ro-Ro ships are found as economically beneficial in most cases. Last of all, the break-even time from low sulphur fuels to scrubber types is presented to guide shipowners in finding the best alternative with respect to ship ages. [ABSTRACT FROM AUTHOR]

Atmospheric emissions related to harbor-related activities can significantly contribute to air pollution of coastal urban areas and so, could have implications to the citizens' health that live in those areas. Of great concern is the local impact of the emissions that are generated while ships are at berth, since not all types of ships switch off the main engines. This paper intends to investigate the influence of the stack configuration for generic cargo ships on the exhaust smoke dispersion, using the Port of Leixões as a case study and a series of wind tunnel experiments with support of Particle Image Velocimetry (PIV) technique. For that, different configurations of the stack of a cargo ship (in terms of height, geometry and diameter) were simulated under the typical wind conditions of the study area. The PIV results indicate negligible differences between the medium and long stack height, with the short stack height presenting a strong impact on the flow field around the stack. For the short stack height, the flow field is not only disturbed by the stack, but also by the cargo ship bridge, with both obstacles promoting disturbances on the flow field and creating a large wake turbulence effect, which is important for the downwash phenomena. Regarding the effects linked with two distinct geometries (straight or curved), the results show that the straight chimney led to higher perturbation of wind field when compared with the curved geometry. The curved stack presents an increase of vorticity, indicating the generation of more turbulent structures. The PIV results also confirmed that higher wind velocity at the inlet conducts to higher vorticity levels, as well as a higher number of Kelvin–Helmholtz structures. For distinct wind conditions the PIV measurements point out different patterns, indicating the northern wind direction as the most favorable condition for the exposure of dock workers to pollutants. Overall, the results showed that a ship stack with a curved end, medium length and smaller diameter has the capability to promote the behaviors in the flow that are coherent with increased pollutant dispersion. [ABSTRACT FROM AUTHOR]

This article introduces novel extreme value prediction method that can be used for a variety of offshore engineering applications. First, to demonstrate the novel method, fictitious data from a non-linear Duffing oscillator and measured wave heights were used as examples. The second incident included a container ship that experienced significant deck panel strains while traveling across the Atlantic Ocean in bad weather. The main concern for cargo ship transportation is potential loss of container owing to violent movements. It is challenging to model such a situation because waves and ship motions are both non-stationary and complicatedly nonlinear. Extreme motions greatly increase the role of nonlinearities, activating effects of second and higher order. Furthermore, due to the scaling and the choice of sea state, laboratory testing may also be called into doubt. Therefore, data collected from actual ships during difficult weather voyages offers a special perspective on the statistics of ship motions. This paper aims to highlight an alternative method of extrapolation that is based on intrinsic properties of the data set itself and does not assume any extrapolation functional class. Extreme value predictions typically originate from certain statistical distribution functional classes to fit the data and then extrapolate. Engineering design can make use of the unique extrapolation method that has been proposed. The proposed method's forecast accuracy has been verified in comparison to the Averaged Conditional Exceedance Rate (ACER) extrapolation method. • A novel deconvolution method for extreme value predictions is introduced. • Real life cargo vessel onboard measured has been used to validate novel method. • The method has been validated by comparison with other well established method. [ABSTRACT FROM AUTHOR]

In order to detect special nuclear materials and other radioactive materials in Security and Defense scenarios, normally, a combination of neutron and gamma-ray detection systems is used. In particular, to avoid illicit traffic of special nuclear materials and radioactive sources/materials, radiation portal monitors are placed at seaports to inspect shipping-container cargo. Despite their large volume (high efficiency), these detection systems are expensive, and therefore only a fraction of these containers are inspected. In this work, a novel mobile radiation detection system is presented, based on an EJ-200 plastic scintillator for the detection of gamma rays and beta particles, and a neutron detector EJ-426HD plastic scintillator (with 6Li) embedded in a compact and modular moderator. The use of silicon photomultipliers in both detectors presented advantages such as lightweight, compactness, and low power consumption. The developed detection system was integrated in a highly maneuverable multirotor. Monte Carlo simulations were validated by laboratory measurements and field tests were performed using real gamma-ray and neutron sources. The detection and localization within one meter was achieved using a maximum likelihood estimation algorithm for 137Cs sources (4 MBq), as well as the detection of 241Am–beryllium (1.45 GBq) source placed inside the shipping container. [ABSTRACT FROM AUTHOR]

The transport of liquefied natural gas (LNG) has significant impact on traffic capacity of waterways, especially the approach channels shared by LNG carriers and other types of ships (general cargo ships, container ships, etc.). Few studies take the behavioral characteristics of LNG carriers and their impacts into consideration. In this paper, we propose a framework for capacity analysis of shared approach channels based on the spatial–temporal consumption method. It consists of three modules: (1) the tide module predicts the tidal height and tidal time for identifying the time windows for LNG carriers; (2) the spatial–temporal consumption module is introduced to calculate the capacity of approach channels; (3) the LNG carrier navigation module is for analyzing the characteristics of LNG carriers and the impact on the capacity of approach channels. A spatial–temporal indexed chart is designed to visualize the utilization of the spatial–temporal resources. A case study on the approach channel of Yueqing Bay near the east coast of China is conducted to verify the effectiveness of the framework. The utilization rates of the approach channel and the impact of LNG carriers are presented using our method. The results of the case study indicate that the proposed traffic capacity analyzing framework can provide support for making traffic management strategies. [ABSTRACT FROM AUTHOR]

This paper deals with the estimate of uncertainties affecting still water hull girder loads of bulk and dry cargo ships. In strength assessment of ships, two main categories of acting loads are considered: still water loads and wave induced ones. While the latter are generally defined bearing in mind their stochastic nature, this is not the case for still water loads, which are basically deterministically considered. The underlying assumption is that there is an overall control of the operational profile during the service of a ship. However, this is not the case in actual fact, especially for general dry cargo ships and bulk carriers, since the loading/unloading process cannot be fully controlled by the crew, often resulting into loading conditions rather different from those planned by the designer. Based on an earlier work, where loading conditions of the above-mentioned ship types were statistically analyzed, in the present paper Monte Carlo simulations are used to estimate the uncertainties affecting the hull girder still water loads of ships in service, showing that their allowable values can be exceeded due to inaccuracies in ship and cargo management. • This paper deals with the estimate of uncertainties affecting still water hull girder loads. • Still water loads are considered deterministic but there is no full control of ship operational profile during service. • Often loading conditions in a voyage leg are rather different from those planned by the designer. • Monte Carlo simulations are used to estimate uncertainties of the hull girder still water loads. • Probability of exceedance of allowable values due to inaccuracies in ship and cargo management is estimated. [ABSTRACT FROM AUTHOR]

Greenhouse gases and other air pollutants emitted from ships account for an unneglectable proportion of the global total. Given the generally high correlation between fuel consumption and emissions, improving the energy efficiency of ships is an important pathway towards cleaner shipping while ensuring sustainable development. In developing a global mechanism for the energy efficiency of ships, an appropriate indicator is a prerequisite for performance benchmarking. Yet due to commercial sensitivity or distorted metric results, the existing indicators are widely questioned. To address these shortcomings, an alternative metric, called Energy Efficiency Performance Indicator (EEPI), is proposed by this paper through semi-empirical analyses. Through introducing a novel proxy of "transport work" informed by the estimation results of an unobserved effects model and quantile regressions, EEPI can yield rational metric results without relying on commercially-sensitive data. Given its simplicity, practicability, unbiasedness and adaptability to the existing policy framework, EEPI can be potentially used as a benchmarking tool, alone or in conjunction with a rating mechanism, to create incentives for better energy efficiency performance and cleaner operation. Though derived from oil tankers, EEPI is theoretically applicable to other cargo ships that share similar operational patterns, such as bulk carriers and liquid chemical tankers. It is also potentially applicable to other ship types with certain revisions. Given the challenges of its application in practice, however, EEPI proposed by this paper can be regarded as a prototype for further improvement. • An alternative operational energy efficiency indicator (EEPI) is proposed. • Unobserved effects are taken into account taking merits of panel data set. • EEPI overcomes vital shortcomings of other candidate indicators. • Performance of EEPI in practice is demonstrated based on statistical data. • EEPI can serve as a benchmarking tool for stimulating cleaner marine operation. [ABSTRACT FROM AUTHOR]

In this paper, we perform a comprehensive study of various semi-empirical methods using publicly accessible experimental data on added resistance in waves with different ship types and conditions. Based on the analysis results, a new method (So-called "Combined method") is proposed, combining two existing methods, which are available in arbitrary wave headings. The results from the two methods are combined smoothly using a tangent hyperbolic function according to wavelengths and wave headings. The coefficients constituting the function are tuned to minimize mean squared error between predictions and model experiments. Finally, the new Combined method is verified by full-scale measurements of a general cargo ship and a container ship, and it seems to give good agreement with measurements in all analysis areas, compared to existing semi-empirical methods. Especially, it showed better performance in estimating added wave resistance at high waves, resonance frequencies, arbitrary waves, and low speeds. • Investigated semi-empirical methods for added wave resistance using experimental data • Proposed a new method of combining the two results available in arbitrary waves • Showed improvement of the new method by validation with two ships' in-service data • Performed well at high waves, resonance frequencies, arbitrary waves, and low speeds [ABSTRACT FROM AUTHOR]

Maritime shipping is under increasing pressure to alleviate its environmental impact. To this end, life‐cycle footprint accounting provides a foundation for taking targeted measures in the green transition of shipping. This study used the process‐based hybrid life‐cycle inventory (LCI) modeling approach to estimate the "cradle‐to‐propeller" footprint of ships, including primary energy consumption, carbon dioxide emissions, and sulfur dioxide emissions. We used the input–output LCI model to calculate the embodied energy and emissions associated with the material and fuel use of ship manufacturing. We used a bottom‐up emission model and global marine traffic data to estimate the operational footprint of different types of ships. Based on 382 cargo ships (including bulk carriers, container ships, and general cargo ships) constructed in mainland China between 2011 and 2015, we estimated that the embodied footprint accounted for <10% of the cradle‐to‐propeller footprint under the pre‐2019 policy scenario. In terms of life‐cycle energy intensity (MJ/nm/1000 deadweight tonnage [DWT]), the large bulk carrier (>100,000 DWT) establishes the lowest value (46), followed by the small (0–100,000 DWT) bulk carrier (96), the large container ship (133), the small container ship (196), and the small general cargo (238). The bulk carrier was identified as the most energy efficient among the three ship types, and ships with larger capacities (i.e., DWT) had higher energy efficiencies than ships with lower capacities. Our study provides a comprehensive understanding of the life‐cycle footprints of cargo ships, thus enabling better evidence‐based policymaking to transition the global marine‐shipping industry to a future of greener energy. [ABSTRACT FROM AUTHOR]

Purpose: Acute poisonings of workers handling shipping containers by fumigants and other harmful chemicals off-gassed from cargo have been reported but (sub)-chronic neuropsychological effects have not been well studied. Methods: This cross-sectional study assessed, using standardised questionnaires, current (past 3-months) neuropsychological symptoms in 274 container handlers, 38 retail workers, 35 fumigators, and 18 log workers, all potentially exposed to fumigants and off-gassed chemicals, and a reference group of 206 construction workers. Prevalence odds ratios (OR), adjusted for age, ethnicity, smoking, alcohol consumption, education, personality traits and BMI, were calculated to assess associations with the total number of symptoms (≥ 3, ≥ 5 or ≥ 10) and specific symptom domains (neurological, psychosomatic, mood, memory/concentration, fatigue, and sleep). Results: Compared to the reference group, exposed workers were more likely to report ≥ 10 symptoms, statistically significant only for retail workers (OR 6.8, 95% CI 1.9–24.3) who also reported more fatigue (OR 10.7, 95% CI 2.7–42.7). Container handlers with the highest exposure-duration were more likely to report ≥ 10 symptoms, both when compared with reference workers (OR 4.0, 95% CI 1.4–11.7) and with container handlers with shorter exposure duration (OR 7.5, 95% CI 1.7–32.8). The duration of container handling was particularly associated with symptoms in the memory/concentration domain, again both when compared to reference workers (OR 8.8, 95% CI 2.5–31.4) and workers with the lowest exposure-duration (OR 6.8, 95% CI 1.5–30.3). Conclusion: Container handlers may have an increased risk of neuropsychological symptoms, especially in the memory/concentration domain. Retail workers may also be at risk, but this requires confirmation in a larger study. [ABSTRACT FROM AUTHOR]

The International Maritime Organization (IMO) has enforced stricter limits on the Greenhouse Gas (GHG) emission due to environment and climate concerns. Many measures have emerged to reduce GHG emission from shipping. However, the effectiveness and applicability of any measure depend on ship type, ship size, operational mode and the operating ocean environment. Estimation of ship fuel consumption and emission in actual shipping scenarios are fundamental input to evaluate the impacts of shipping on the environment and climate, and to evaluate the effect of new measures to reduce GHG emission. A model for estimating ship fuel consumption and emission, based on ship hydrodynamical models and machine learning techniques, utilizing information from Automatic Identification System (AIS), the ship information database and metocean data is presented in this paper. The model is able to estimate the ship fuel consumption at high computational speed by utilizing machine learning (ML) technology, to evaluate the effect of new measures to reduce GHG emission. The power consumption calculated by the combined model is compared with measurement data from two container ships and two bulk carriers for validation. This validation shows that the model can predict ship power consumption well. • A model is developed for fuel consumption, which is applicable on big ship fleet. • The model is modularized, combining physical and machine learning models. • The model can investigate the effect of new technology to improve ship efficiency. • The model exploits a Specific Fuel Oil Consumption module based on DNV database. • A methodology to impute missing information using machine learning is proposed. [ABSTRACT FROM AUTHOR]

In recent years, ship exhaust gases have become an essential source of air pollution. A detailed study of ship exhaust emissions can accurately reflect air pollution intensity in ports with high waterborne traffic. In this paper, ship exhaust emissions in 2018 in the west area of Shenzhen port are estimated based on ship AIS data and fitting results between ship characteristics, including ship length, engines' power, gross tonnage, and maximum speed. This research reveals the emission distributions according to different ship types, months, and operation conditions. The results showed that the contribution rate of exhaust emissions of cargo ships and container ships is at the forefront, In contrast, ship emissions in hotelling and normal cruising are more significant than those in maneuvering and slow steaming conditions. The results presented in this research provide a basis for developing emission reduction measures in port area management and provide relevant experience to other world port areas. [ABSTRACT FROM AUTHOR]

To thoroughly figure out the distribution and formation mechanism of maritime accidents, this study proposes a domino effect model based on temporal association rules (TAR) to analyze and mine the secrets behind the accident—the formation mechanism of accident chains. In this study, the British Marine Accident Investigation Branch (MAIB) accident reports are gathered and examined. Of which, Ro-Ro ships, general cargo ships, and container ships are the top three ship types discussed. The domino effect model is applied to the detected accidents, yielding a series of results. These show that the resulting values from unsafe working practices to death while working are very high and are 8.622 (Ro-Ro ship), 5.920 (General cargo ship) and 6.441 (Container ship), respectively. It indicates that unsafe working practices are very prone to accidents involving death while working. The approach is ubiquitous, and the accident chains compiled from them may be widely employed in marine accident prevention and proactive safety management. [ABSTRACT FROM AUTHOR]

Abstract: The aim of this paper is to design a ship autopilot using a multi-controller structure by introducing several working points. The control design of each local controller is achieved using internal model control structure. An illustrative example shows the application of the proposed control structure to a container ship in real condition of navigation. [Copyright &y& Elsevier]

Abstract: Ultra large container ships are rather flexible and exposed to significant wave deformations. Therefore, hydroelastic strength analysis is required for these types of ships. Coupling of beam structural model and 3D hydrodynamic model is preferable for the reason of simplicity. In this paper, the contribution of a large number of transverse bulkheads to general hull stiffness is analysed. The prismatic pontoon with cross-section of a large container vessel is considered for this purpose. Stiffness parameters are determined by employing the torsional theory of thin-walled girders for ship hull and orthotropic plate theory for bulkheads. The procedure is evaluated by 3D FEM torsional analysis with transverse bulkheads included/excluded. [Copyright &y& Elsevier]

The paper presents the results of an experimental investigation of the shipping of water on the bow of a containership. Model tests were carried out in head regular and irregular waves of large amplitude, and measurements were taken of: the absolute and relative motions, the structural loads, the height of water and the impact pressure on the deck, and the horizontal impact pressure and total force on the first line of containers on the bow. [ABSTRACT FROM AUTHOR]

Structural steel renewal in ship repairing is a routine work throughout the service/operational life of a ship. Prior information about the renewal quantity helps the shipowners to allocate an appropriate budget and the shipyard to prepare the proper ship repairing schedule. It, in turn, helps the shipowners make a financial commitment for cargo. Likewise, prior information about the location of steel renewal works can help the shipowners to prepare the ship before going to the shipyard and the latter to plan for the required logistics. By doing so, the shipowners would be able to save cost in terms of less idle time in the shipyard. The latter can also increase the revenue in terms of minimizing mobilization time. Structural steel renewal location-related information for 123 cargo ships of various ages, deadweights, and types were collected from a single shipyard. Data of renewal locations of selected structural members were analyzed and presented in both tabular and graphical forms. The intention was to show the behavior of renewal locations with respect to the ship's dimension appropriate for respective structural members, age, and length of the ship. In this article, the authors have attempted to identify and establish the possible root causes that influence the renewal locations and also to investigate and suggest the potential interrelationships between renewal locations, age, length, and type. [ABSTRACT FROM AUTHOR]

Due to the effects of Hurricane Patricia (2015), the bulk freighter "El Llanitos" ran aground in the rocky intertidal zone of Colima, Mexico. We assessed the impact of this ship's stranding on a population of the gastropod Plicopurpura pansa. Toxic elements, hydrocarbons, shell deformities, presence of tumors, imposex, and morphological relationships were analyzed. Two years after the stranding occurred, high cyanide concentrations (0.0363 mg/l) and Ni concentrations above permissible limits (3.35 mg/l) were found in surface seawater. Hydrocarbon concentrations were high in the aft zone of the ship and decreased towards the bow area of the freighter. The P. pansa specimens collected closest to the ship structure presented a high prevalence of tumorations in the structure of the foot and morphological anomalies in the shell structure; imposex was 32% and there was evidence of effects on the growth indicator. The evidence presented here supports the existence of a significant impact from the grounding of the ship on a protected gastropod species associated with the rocky intertidal zone on the coast of Colima. The potential of P. pansa as a bioindicator species of pollution caused by toxic elements and hydrocarbons associated with stranding events in the tropical Pacific is documented. [ABSTRACT FROM AUTHOR]

The increasing economic cost and environmental impact of maritime transportation necessitate the reduction of fossil fuel consumption of ocean-going cargo ships. Although fundamental ship propulsion system theory is well-known and is at a mature stage of development, there is still an enormous variety in the assessment methodology of (environmental) transport performance of ships. Furthermore, calibration of ship propulsion system model parameters with testbed, towing tank and full-scale measurement data is rare, as these measurements are both difficult and expensive. Finally, the effects of different power management strategies on the ultimate energy conversion effectiveness of typical cargo ships have rarely been investigated systematically. In this paper these three issues are discussed, addressed and solved for a representative benchmark chemical tanker. This ship was chosen to investigate the so-called energy conversion effectiveness under various propulsion control and electric power generation modes, as ample real ship data is available. The transport performance assessment of the ship's power plant is generalised for hybrid arrangements with either Power-Take-Off or Power-Take-In. The results show that an optimal combination of propulsion control, power management and voyage planning will further reduce the global fuel consumption and CO 2 emissions produced by the shipping industry. • Energy effectiveness of ocean-going ship based on comprehensive theoretical framework. • Propulsion control modes are considered when evaluating ship transport performance. • Electric generating modes are considered when evaluating ship transport performance. • Adequate parametric first principle model of ship propulsion and power generation. • Model based on real engine, tank test and sea trial data of a representative ship. [ABSTRACT FROM AUTHOR]

Canakkale Strait (Dardanelles), is one of two straits that have Turkey with Bosphorus. This strait, which has a length of 38 miles, provides the connection of countries with a coast to the Black Sea to the Mediterranean. 43454 ships pass through the strait annually. According to 2019 data, 45.33% general cargo ship, 21.43% bulk carrier, 21.78% tanker, 6.43% container, 0.65% ro-ro, and 0.61% passenger ship, and 3.77% other type of ship passed. Therefore, by including the Canakkale 1915 bridge which will be completed in 2023, the six most frequent ship types were examined and their emission values were calculated in this study. [ABSTRACT FROM AUTHOR]

Structural steel renewal (repair/replacement) is carried out as a part of routine maintenance of a ship during its service life. Structural steel renewal is a result of the structural deficiencies beyond the limit set by the classification societies, regarding either scantling (reduction in thickness) or structural deformations (yielding, buckling, bulging, etc.), or both. Reduction in thickness of steel (mainly caused by corrosion) and distortion (mainly caused by ship motion and damage due to cargo) are due to many particular natural phenomena. Structural steel replacement cost is the highest in a ship repairing invoice for a shipowner, and it also consumes the maximum resources from a shipyard. Hence, prior information about the scope of structural steel replacement might help the shipowner with proper budget allocation and schedule to meet the financial commitment. It may also help the shipyard to prepare a realistic time and berthing plan by optimizing its resource allocation and utilization. Information related to structural steel repair (weight in kg) for 123 cargo ships of various ages, deadweight, and types were collected from a single shipyard. Structural steel repairing data were then analyzed and presented in both tabular and graphical forms to show the behavior of structural steel repair as a function of age, deadweight, type, cubic number, and gross tonnage of ships. In this article, the authors have made an attempt to identify those independent variables that influence structural steel renewal (the dependent variable) and their interrelationship. [ABSTRACT FROM AUTHOR]

Piracy attack is a serious safety problem for maritime transport worldwide. Whilst various strategic actions can be taken, such as rerouting vessels and strengthening navy patrols, this still cannot completely eliminate the possibility of a piracy attack. It is therefore important for a commercial vessel to be equipped with operational solutions in case of piracy attacks. In particular, the choice of a direction for rapidly fleeing is a critical decision for the vessel. In this article, we formulate such a problem as a nonlinear optimal control problem. We consider various policies, such as maintaining a straight direction or making turns, develop algorithms to optimize the policies, and derive conditions under which these policies are effective and safe. Our work can be used as a real-time decision making tool that enables a vessel master to evaluate different scenarios and quickly make decisions. [ABSTRACT FROM AUTHOR]

This paper summarizes the results of extensive research on the design loads used for strength assessment of merchant ship structures such as tankers, bulk carriers, and container ships. The main aim of the research was to develop practical estimation methods of design loads having rational technical backgrounds acting on primary structural members of tankers, bulk carriers, and container ships. During this study we will do the following. (1) The design sea states that closely resemble the actual sea states which are considered as the most severe for hull structures are proposed. (2) The practical estimation methods of the design sea states are proposed by parametric studies using the results of series calculation of representative merchant ships. (3) The practical estimation methods of design regular waves resulting in the same level of stresses as that induced in irregular waves under the design sea states are proposed. (4) The practical estimation methods of the design loads such as ship motions, accelerations, hull-girder bending moments, and hydrodynamic pressures that are induced under design regular waves are briefly introduced. The findings in this study have been summarized and implemented in the new design standards for tanker, bulk carrier, and container ship structures ("Guidelines for Tanker Structures," 2001, Nippon Kaiji Kyokai; "Guidelines for Bulk Carrier Structures," 2002, Nippon Kaiji Kyokai; "Guidelines for Container Carrier Structures," 2003, Nippon Kaiji Kyokai). [ABSTRACT FROM AUTHOR]

Parametric rolling in head seas can cause serious safety issues for ships with the possibility of cargo shift, damage and difficult working conditions for crew. This work investigates the prediction of its occurrence and the factors that influence its onset and magnitude. It also seeks to establish the effect of bilge keels on containerships. The threshold boundaries for the inception of parametric roll, for a typical containership operating in Australian ports, are established using the Mathieu equation. Good agreement was found between the numerical predictions and results from a set of towing tank experiments. Fitting of bilge keels to the containership model was found to be an effective way of reducing the roll angles induced by parametric roll, and in some cases their presence can prevent its onset. A simplified method for use by masters to avoid the onset of parametric roll is also presented. [ABSTRACT FROM AUTHOR]