A simple and low cost drifting buoy using Android smart phone was developed. The drifting buoy can detect its own position using GPS system and also measure wind velocity and direction. The measured data can be immediately transmitted to a distant location by 3rd generation mobile phone network which is available in coasting area. A field test was conducted to verify its basic function and found that the system can work well in coastal water and is applicable to monitoring and forecasting floating debris as well as spilled oil.
Marine debris washed ashore causes serious environmental effects. It is both effective and efficient to catch and collect floating debris before it reaches shore. In this study, the authors examined a system to catch and collect marine litter floating on sea. The system is composed mainly of a floating fence, a towing line and a towing ship. The floating fence, which is laid without mooring on the sea current as the drifting debris, consists of a floating body, a catching net, and a n underwater brake. The underwater brake decelerates the floating fence drift speed so that floating debris can be caught and collected. The shapes and conditions of the floating body and catching net were selected based on the results of model basin tests in waves. The floating fence drift speed was estimated by considering the resistance characteristics of the floating fence obtained in model tests. Finally, the transportation and recovery system of the collected garbage was designed using a pusher-barge system.
The amount of marine litter from surrounding countries washed ashore in Tsushima, Nagasaki Prefecture has continuously increased. Therefore, a marine litter disposal system needs to be implemented locally. The Research Committee on Marine Litter Disposal aims to contribute to local industrial entrepreneurship and development by converting by-products obtained from the processing of marine litter into thermal resources. As a first step, this paper describes a simple yet locally feasible method of reducing the volume of foam polystyrene which constitutes the bulk of marine litter.
The shore and coastal environment is polluted by the transfer and disposal of marine litter. Adverse effects on the ecosystem and on human life are felt in the remote islands and regions in Okinawa, Kagoshima, Kumamoto, and Nagasaki prefectures. Depopulation and aging continues in these areas. Therefore, it is important to devise an energy- and labor-efficient disposal system to collect, transport, dispose or process marine litter. The amount of expanded polystyrene washed ashore is enormous, which creates waste transport problems. On the other hand, an adequate energy supply is necessary when collected debris is recycled on site. Since most of these remote islands and regions have no power supply, the use of natural renewable energy as power source was considered. Based on the foregoing discussion, the author examined the energy and labor savings in the transportation and recycling processes of a marine litter disposal system.
Amendments have been made to the MARPOL Annex VI Regulations for the prevention of air pollution from ships, and energy efficiency regulations for ships have made mandatory the Energy Efficiency Design Index (EEDI) for new ships, and the Ship Energy Efficiency Management Plan (SEEMP) for all ships. Further energy-saving improvements will be required for ships. An induction type power turbine generator system which focused on high energy-saving performance and easy operation has been developed and applied in a 97,000DWT bulk carrier by Japan Marine United Corporation. This report describes the system and presents the confirmation results on the system’s performance and function in sea trials and during its maiden voyage.
The evaluation test of a newly developed self-polishing anti-fouling bottom paint has been carried out by the training ship Fukae-maru (449G/T) of the graduate school of maritime sciences, Kobe University. In the past four years, 4 types of bottom paints, including both low-friction coating and conventional paint types, have been evaluated through speed trials at Harima-Nada of the Seto Inland Sea. The hull frictional resistance based on the viscosity of sea water accounts for 70-80% of the total resistance at low speed range and accounts for 40-50% at high speed. Reducing the frictional resistance of the bottom shell plating leads not only to a decrease of ship’s fuel consumption but also to a reduction of greenhouse gas emissions. Results of speed trials show a fuel saving of more than 4 % with low friction coatings as compared to that with conventional anti-fouling bottom paints.
HOPE-Light is software to study the dimensions of cargo ships. It not only provides the ship’s propulsion power but also its maneuverability, sea keeping and cavitation performance related to hull vibration. It specifies main engines suitable for the ship and presents the fuel consumption of each engine. It also gives the rudder form, propeller design, speed in waves and EEDI (Energy Efficiency Design Index) which is applied to vessels for international voyage and having gross tonnage of 400 and above from January 2013. In this paper, two examples of HOPE-Light applications are also presented. One is the relationship between propeller diameter and ship’s fuel consumption at the same speed. The other is the change of EEDI value against the change in deadweight caused by the fullness of ship at the same dimension.
A study was conducted on the feasibility of crudely processed fatty acid methyl ester (FAME). FAME is receiving considerable attention as a promising alternative fuel to address global warming. However, its high cost and its long and complicated manufacturing process prevent its wider use. If the amount of methanol used in the fuel making process is reduced, the fuel cost would be reduced. The aim of this study is to clarify the feasibility of simplifying the FAME manufacturing process and of reducing costs by decreasing the amount of methanol used. Therefore, in the experiment described in this paper, test fuels with methanol percentages of 10, 20, and 30% were prepared. Moreover, the pre-manufacturing process and the washing process were eliminated. In addition, FAME produced by the complete manufacturing process was used as the reference fuel. The lower calorific value, density, surface tension, and kinematic viscosity of the test fuels were measured. It was found that the reduction of methanol had little effect on the thermophysical properties. Moreover, the ignition temperature and the ignition delay were measured and found to improve with esterification. No significant differences were found for all FAME fuels. Finally, all FAME fuels were burned in a conventional 273-cc diesel engine. Although the specific fuel consumption was slightly higher, the smoke scale in the exhaust gas was lower than that of gas oil. FAME with 20% methanol was especially similar to that with 30%. There were only small differences between crudely processed FAME manufactured using the simplified process and that which was manufactured with the complete process.
In this paper, the effects of DLC film coated on a stainless steel (SUS304) on fretting wear in seawater are examined. Special attention is focused on the effects of mating materials and the cathode rust prevention of Zn attached to the SUS304 on fretting damages. The experiments show that using soft copper alloy as the mating material is effective for preventing fretting damage of DLC film and that Zn is very effective for preventing damage in seawater.
The role of marine engine accident prevention has become more important for marine engineers working in a complex environment. Various risk factors caused by human errors result in serious accidents. However, this argument does not account for the relationship between error and accident. The purpose of this study is to introduce an integrated multi-dimensional approach to investigate errors committed by engineers. For this work, the characteristics of total human errors were investigated by taking 298 marine accident records from the Japan Marine Accident Inquiry and 104 incident records from engine trouble casebooks. Different incident records are compared by employing quantification theory III, which is one of the measurements for multivariate analysis. This research identifies actualized and latent events by using accident records and incident records without near-accidents. Furthermore, the authors present recommendations for safety guidelines required for safe engine operation by analyzing both compositions of factor and total image errors.