Big Ships Research Articles

Short-circuit current analysis of DC distribution system in a ship with non-electric propulsion

Converting conventional AC radial shipboard distribution system to DC system has been recognized as a potential high impact solution to reduce ship’s fuel consumption. As big ships in Indonesia commonly use low voltage AC (LVAC) distribution system an effort to apply low voltage direct current (LVDC) distribution system without replace the propulsion system is a plausible choice. However, technical and economical investigations are required before recommendation to convert the shipboard distribution system to LVDC is officially launched. In this study, technical aspect in the term of short-circuit current is discussed. The goal of this study is to analyze how much the impact on the short-circuit current when LVDC system replaces LVAC system. The impact may affect the feasibility of LVDC system as the short-circuit current in a system dictate the scheme and capacity of the protection devices. Numerical simulations on a sample vessel are performed to obtain the profile of maximum short-circuit currents on all panels. The results show that the utilization of LVDC system decreases the short-circuit current by 10 times. Further investigations on the economic aspect needs to be performed to give clearer view of the feasibility of the LVDC system.

“In the Wake of a Big Ship”: The Sailing Must Go on!

“In the Wake of a Big Ship”: The Sailing Must Go on!

The Value of Going To Sea on Big Ships and the Advantage of Multiple Tracers for GEOTRACES Style Programs

Following a brief description of a typical GEOTRACES oceanographic cruise, this article illustrates the benefits of the multidisciplinary and multi-tracer approach that has characterized GEOTRACES. The value and organization of this type of research cruise—which requires many people and large vessels—are discussed in relation to the resulting carbon footprint and the potential alternatives.

Prediction of the physico-chemical properties of vegetable oils using optimal non-linear polynomials

Vegetable oils (VOs) comprise 90%–98% triglycerides (three fatty acids esters and glycerol), with trace amounts of mono-glycerides and di-glycerides. The content of glycerides in VOs can vary depending on the specific type of oil, the processing methods used, and other factors such as the cultivar and harvest date. VOs have been examined for usage in different applications due to their physicochemical properties, including stationary engines, big ships, and Diesel engines of low and medium speed. There are around 350 VOs that have the potential to be used as fuel sources, the vast majority of which have yet to have their physicochemical properties investigated. Regression models based purely on VOs fatty acid content are beneficial in this context. This study conducts a regression analysis of VOs density (DE), kinematic viscosity (KV), flash point (FP), and low and high heating values (LHV and HHV) as a function of their fatty acids. Several experimental databases were selected, including the values of VOs fatty acid composition and physico-chemical properties. Optimal non-linear polynomials were chosen for the regression procedure. Scheffé polynomials offer different fitting alternatives to adjust the VOs experimental databases using their five main fatty acids: from simple linear polynomials (including five terms) to full cubic polynomials (including 35 terms). The polynomials are validated by showing how well their results correspond with the experimental databases. The standard error values for the proposed full polynomials concerning the databases for DE, KV, FP, LHV, and HHV are 0.70%, 7.79%, 7.86%, 1.66%, and 0.19%, respectively.

Economic and environmental impact assessments of a newly designed energy system for marine applications

Marine transportation via the world's oceans is a critical way to convey goods and fuels between continents that cannot be performed cost-effectively by any other means. However, big ships heavily rely on fossil fuels, aggravating global carbon emissions. A key resolution to this dilemma is to employ clean fuels to reduce carbon emissions. This research paper introduces a new hybrid compound marine engine comprising a gas turbine, a solid oxide fuel cell, and a steam Rankine cycle. Three types of analyses, such as exergy, exergoeconomic, and exergoenvironmental analyses, are conducted on this proposed engine. It is found that the engine can produce a power of 15.5 MW, which is more than 48% compared to the traditional marine engine power, and the engine performance has up to 61% energy efficiency and 43% exergy efficiency. However, the exergetic efficiency of this engine based on fuel and product principal is 60%, which is more than 17% compared to its exergy efficiency. This engine has a 218 $/h Levelized cost rate and 139 mPt/h environmental rate. Finally, the average overall specific product exergy cost and environment are obtained to be 59 $/GJ and 20 mPt/MJ. By comparing five fuel blends, methane and hydrogen are the most economical and have the least impact on the environment; the second option is ethanol blend.

Application of Generator Capacity Design Technique Considering the Operational Characteristics of Container Ships

The advantages of economies of scale in marine logistics and transportation can be obtained by building bigger ships. As ship sizes increase, so do their propulsion systems, requiring that stable and high-efficiency power must continuously be supplied. In general, ships’ operations require power lower than the installed generator capacity. However, when the generator is operated at a low load, its efficiency decreases. In this study, based on actual operation data, the load requirements for each operation mode were analyzed, and a diesel-generator-based power system was designed. We present a generator capacity optimization calculation method through generator capacity. The proposed strategy maximizes the space utilization and efficiency of the ship while minimizing the generator’s power consumption. The generator’s fuel consumption, operating time, and efficiency were compared and analyzed to verify the proposed strategy’s efficacy. In conclusion, the proposed strategy demonstrated the effect of reducing fuel consumption by 2.2%, increasing generator efficiency by 8.4%, and reducing costs by 5.14% compared to the existing onboard generator capacity for the same vessel.

Detection of Sea-Surface Small Targets Masked by Range Sidelobes of Large Objects

Many high-resolution maritime radars for sea-surface small target detection transmit pulses with large time-bandwidth-products to increase transmitter power and to use the pulse compression technique for high range resolution. On the sea surface, besides small targets of interest, there exist many uninteresting large objects such as big ships, reefs, and offshore platforms for oil production. Large objects have too strong radar returns and their range sidelobes often mask wide range intervals. In these range intervals, masked small targets are difficult to be detected directly. In this article, a complete scheme is proposed to find small targets masked by range sidelobes of large objects in high-resolution maritime radars. In this scheme, high-precision reconstruction of radar returns of large objects is crucial because tiny reconstruction errors are enough to mask weak returns of small targets of interest. An algorithm using the linear programming and oversampled high-resolution range profile model of a large object is given to obtain high-precision reconstruction of the strong radar returns of a large object. From residual radar returns removed the reconstructed strong returns, a near-optimal coherent detector under sea clutter modeled by the spherically invariant random vector with inverse Gamma texture plus colored Gaussian noise is constructed to find masked small targets. Simulated experiments and real measured radar data are used to verify the effectiveness of the proposed scheme and method and reveal their limitations. The results show that the proposed scheme and method are all effective unless small targets fall into the range mainlobe regions of large objects.

Commentaria archaeologica et historica (IV)

Commentaria archaeologica et historica (IV)

‘The response is like a big ship’: community feedback as a case study of evidence uptake and use in the 2018–2020 Ebola epidemic in the Democratic Republic of the Congo

IntroductionThe 2018–2020 Ebola outbreak in the Democratic Republic of the Congo (DRC) took place in the highly complex protracted crisis regions of North Kivu and Ituri. The Red Cross developed...

Applications of artificial intelligence in ship berthing: A review

Ship berthing operations in restricted waters such as ports requires the accurate use of onboard-vessel equipment such as rudder, thrusters, and main propulsions. For big ships, the assistance of exterior supports such as tugboats are necessary, however with the advancement of technology, we may hypothesize that the use of artificial intelligence to support ship berthing safely at ports without the dependency on the tugboats may be a reality. In this paper we comprehensively assessed and analyzed several literatures regarding this topic. Through this review, we seek out to present a better understanding of the use of artificial intelligence in ship berthing especially neural networks and collision avoidance algorithms. We discovered that the use of global and local path planning combined with Artificial Neural Network (ANN) may help to achieve collision avoidance while completing ship berthing operations.

Wind tunnel experimental investigation of the aerodynamic coefficients reduction due to sheltering surroundings on a cruise ship moored in port

The recent growth of cruise and container ships size, which is involving the shipping industry, determines the greater and greater importance of evaluating properly the wind actions on such big ships, especially during the mooring phase. Accidents and damages may occur in port areas during extreme wind events due to the breakage of mooring clamps, jeopardizing the safety of human beings and vessels as well as producing significant economic losses. Despite extreme winds are one of the main dangers for large ships within ports and standardised procedures to accurately assess wind loads are still missing. To shed light on this topic, a set of wind tunnel tests was carried out to investigate the shielding effect that the surroundings can play in reducing the wind forces acting on a 1:600 model of the large cruise ship in the Port of Monfalcone (Italy). The longitudinal and transversal forces and yaw moment were measured for three main sets of tests: (1) open sea condition; (2) ship and quay; (3) ship, quay, and other shielding ship upwind. The results showed a strong dependence of the wind load on the cruise ship according to different surrounding configurations. In particular, a reduction of the aerodynamic forces up to 60% for the wind directions orthogonal with respect to the ship was measured. On one hand, this demonstrated quantitatively that the shielding effects of complex surrounding buildings may guarantee an increase in port safety with the reduction of the overall forces acting on ships. On the other hand, it highlights the huge uncertainty which currently characterizes the assessment of wind loads in the mooring system design, pointing out that a novel approach should be adopted in which every mooring system is designed on a specific site-analysis base.

Challenges To The Multimodal Transport Networks Based On Sustainable Growth In The Volume Of Containerized Cargoes

Globalization is a significant factor for optimization of the existing transport chains. It is a major power for sustainable development of containerized transport, the relevant transport infrastructure and terminal equipment. The development of seaports and inland waterway connections became important part in global supply chain. The transportation models which are using multimodal transport service consist from maritime, port and hinterland parts. Choosing the appropriate strategy allows the shipping companies to reduce the transport cost and helps them to be more competitive on the cargo market. This article aims to identify the challenges and prospects for development of multimodal transport operations with containerized cargoes using of system approach to the each subsystems of the multimodal transport chain. To achieve the scope of the paper, research has been done on the global effects that big shipping companies contribute to the final transport cost; to the organization in container terminals and further influence on the local terminal operators; to the improvement of port infrastructure, including the number of offered services and implementation of innovations for increasing terminal efficiency. As a result, the main parameters for evaluation of the importance of one container terminal in the supply chain are defined.

Should the Maharajah be Dethroned ? A Case Study of Air India

Air India, like any other public sector undertaking/government company, is incurring losses and trapped under the heavy burden of debt. The taxpayers’ money is being utilized to keep the sinking Maharajah on a ventilator. The first attempt to sell 76% stake in Air India failed miserably due to several reasons as identified by the transaction advisor of the Government of India. The reasons are Government of India’s 24% ownership and equivalent rights, heavy debt around INR 38,000 crores, fluctuations in macro environment, no individual bidding, consistent losses, and buyers not being able to form a cartel within the given time period. Why is that such a big ship is drowning today ? Is it overburdened with the losses and loans? Why is it unable to introduce some revival strategy ? What are the reasons responsible for its failure? Disinvestment should be the last option, especially for a rich entity and a national carrier like Air India. However, the government is in a hurry to exercise its last option, which is to sell it. The government has now made a second attempt to modify and sell it under promising conditions. The main objective of this case study was to discuss the current situation of Air India and examine the best option available for it, including reverting the decision to sell. The case provided pointers concerning all the options available for the airline.

Mass documentation of archaeological ship timbers: introducing a novel, time-efficient approach

This article introduces the annotated scans method as a new approach to ship timber recording. The proposed method consists of several phases: timbers are first scanned in 3D, these scans are then annotated in Rhino, and finally the timber catalogue is generated using a semi-automated workflow. We compare this approach to the current best practice method for timber recording, namely contact digitising. Based on our experience recording the timbers of the Wismar “Big Ship”, we conclude that the proposed method matches, and in some regards surpasses the current best practice method, most notably in terms of cost and time efficiency.

The “Big Ship” of Wismar: a well-preserved 12th-century cargo vessel from the harbour of Wismar

In December 2017, maritime archaeologists from the state department for archaeology in Mecklenburg Western Pomerania excavated, recovered, and documented a shipwreck in the seaport of Wismar. The wreck of a clinker-built cargo vessel was one of three medieval vessels found during the extension of the commercial port. With riveted outer planking and the presence of bitis, the wreck can be placed in the Nordic shipbuilding tradition. The results of the dendrochronological analysis show that the vessel was built from oak and pine sourced from western Sweden in the period AD 1184–1190. The construction shows striking similarities with a number of large 12th-century cargo vessels found in northern Germany and Scandinavia.

The Influence of Port Tugs on Improving the Navigational Safety of the Port

Port tugs are an important element in port activity and navigational safety issues. Port tugs ensure the safety of big ships while they are entering, manoeuvring, mooring and unmooring, and are of huge importance during other port operations. At the same time, optimizing the number of port tugs and tug bollard pull is also important from a port navigational safety and economic point of view. Calculation and evaluation methods of the optimal request for tugs bollard pull, in particular, port operations, are very important in order to guarantee the navigational safety of the port and ships during the main ship operations in the port. This article provides the number of requested port tugs and bollard pull calculation and evaluation methods on the basis of forces and moments acting on ships. On the basis of real ship voyages and manoeuvring at ports data as well as high accuracy simulators, theoretical methods were used, which were followed by our conclusions and recommendations, which can be used by port harbour masters and tug companies. Modern tugs have become an important element and integral part of modern port navigational safety. Such modern port tugs are also used for navigational safety and other important port functions and activities, such as fire protection and search and rescue operations. The optimal number and capacity evaluation of port tugs depending on port capacity and conditions are studied in this article.

Looking into the future ten years later: big full containerships and their arrival to south American ports

Since 2006, when the Emma Maersk broke into the world of shipping, the growth in containership size has remained a continuous trend.For the last 14 years, since 2006, the enlargement of fullcontainerships size has remained a continuous trend since Emma Maersk broke into the world of shipping. This process - that also affected north-south trades - has crucial implications in the shipping business, particularly in the planning of ports and its services and related activities. This paper analyses the global increase in vessel size and forecasts larger vessels’ arrival to South American coasts. The paper analyses evidence since 2006 to understand the factors behind the trend for bigger ships (fleets between 18,000 and 24,000 TEU) and introduce a validated methodology for the prediction of the size of container ships. Experts presented a consensus vision in which factors associated with infrastructure, economics, technology, and the environment play a crucial role in driving the trend. Next, the paper presents a methodology for forecasting the size of containerships and applies it to Latin America’s trade. The models include two alternative thresholds for the dependent variables (1310 ft LOA and 18,000 TEU of nominal capacity) that are controlled by cascading effect (i.e., the size gap between Latin America and the world’s main trade routes), and the economic activity at the destination countries (represented by port activity). Finally, the conclusions highlight the forecast’s call to take action on infrastructure planning and investments, analyzing issues such as “economies of scale,” concentration, or entry barriers. Overall, the paper warns about the importance of efficient medium-term planning in the port industry to maximize its economic impact.

Progressivism, Collegialism and Autonomy in Muhammadiyah: Threats and Solution

Muhammadiyah is one of the world's largest Islamic movement organizations, contributing to a variety of important areas of life for Indonesians. Muhammadiyah promotes three main characteristics based on community development: progressiveism, collegialism, and autonomy. Unfortunately, as Islamic populism grew stronger, Muhammadiyah became engulfed in a political vortex, endangering the stability of its cadres and giving the public the impression that the government could control the organization. This article evaluates the threats that cause these values to deteriorate and offers treatment options. The solutions offered to maintain the principles of progressiveism, collegialism, and autonomy are to rejuvenate the leadership, build distance from politics, develop community funds, and build supporting business units, according to literature studies and observations in several areas. Furthermore, political education as an effort to formulate political theology for Muhammadiyah members is required so that the big ship of Muhammadiyah does not become divided due to differences in political views and can increasingly contribute to politics at the local-national level without jeopardizing its integrity as a movement organization.

The Moving of Seaport from Labuhan Deli to Belawan in the Period of 1863-1942

Plantation economic growth has the impact on development in various aspects. One of them is shipping and trade development. Before the existence of plantations in East Sumatera, shipping and trade in Medan were centered at Labuhan Deli as a river-port. Since big ships could not sail on the river, it was considered not effective and efficient anymore. Therefore, the Dutch Colonial Government planned to build a seaport located on the sea coast so that loading and unloading would be easy to do, and they selected Belawan to be the new seaport. The research problems were how about the existence of Labuhan Deli by the policy of the Dutch Government on moving the seaport to Belawan and what was their reason for it, and how about shipping and trade business in Belawan. This research used archives and other writing materials from the period of the Dutch Colonial Government in Medan and used historical method. The objective of the research was to find out whether plantation economic condition could change various aspects, including shipping and trade at the time. The result of this research was expected to become the reference for the writing on advanced maritime history, particularly on seaport.

Green Maritime Transport as a Part of Global Green Intermodal Chains

Environmental pollution is increasingly becoming a major global problem. Consequently, companies and policy makers are facing mounting pressure to reduce their impacts of logistics activities and make transport greener. The challenge to reduce the carbon intensity of maritime transport is even more important when we take into equation the fact that carries about 90% of the world trade. While car industry has already taken actions to greener cars, maritime industry is subject to fewer regulations and slower progress. This article overviews upcoming trends of green intermodal chains, initiatives in green maritime transport and how noteworthy is share of their impact in the transport chain as a whole. Speed reduction is one of most important measures which can be implemented right away with win-win impacting on environment and fuel cost. The study analysis environmental impacts of different services to eastern Adriatic ports, with special emphasis of slow steaming impacts on pollution level. The paper exposes that direct lines with bigger ships cause lower emissions of CO2, NOx and SOx and that with decisions of slow steaming the pollution level decreases significantly.