Journal of Marine Technology and Environment 2014 Vol. 2

From technical point of view and from environmental point of view, and also for a sustainable development of our society are needed tools which enable to analyse the effects of human activities, including maritime transport. Refrigerated transport is essential for our society due to the need to preserve and protect food or medical supplies during transportation, to the benefit of the people worldwide. But the education of future marine engineers is in closely connected to environmental protection. The paper is focused on needed to knowledge and to understanding the working principles of the marine refrigerating plans, tools which should be at hand of future marine engineers. These competences should be gained during faculty, through a discipline called “Marine Refrigerationg Plants” included in the curricula of the license program entitled “Electromechanics”, developed in C.M.U. This paper is mainly focused on the selection of refrigerants. There are some classic selection criteria: thermophysical properties, technological and economic aspects, safety and environmental factors; however, in addition to these criteria, others have to be considered: local regulations and standards and “cultural” criteria.

Heat exchangers are devices used to transfer heat between at least two fluids heaving different temperatures; in most of the situations, these fluids are separated by a solid wall. Shell and tube heat exchangers are the most common type of heat exchangers; this is why more attention on their design, optimization and analysis is absolutely needed for energy conservation in the process of heat transfer. This paper presents an approach related to optimum design of shell and tube heat exchangers. The approach relies on the genetic algorithm for optimization of this kind of devices. The genetic optimization algorithm is based on the value of an objective function. It will be assumed that the objective function is the total cost function, which should be minimized. The use of such a method in practice will leed not only to optimal geometric design features, but also to the consideration of economic aspect of these devices.

In order to analyze the magnetic signature of a naval ship, there was employed a physical scale model of the respective vessel. The model was built to a scale of 1:100, respecting the geometric similarity criteria, in terms of main dimensions proportionality. A physical similarity criterion characteristic to the magnetic signature issue was formulated, taking into account the ratio between the hull sheet thickness and the electric and magnetic properties of the ship and the model, respectively. There have been performed a large volume of triaxial measurements of the magnetic signature, to acquire the magnetic field distribution for an horizontal plane situated below the hull, at reference depth. Based on the analysis of magnetic signature components of the model ship, some conclusions regarding their shape can be drawn.

A lot of studies focused on quay transfer operation efficiency. It emphasized on increasing the handling rate and improving the performance by mathematical, modeling or empirical study. Therefore, this study aimed to study delay factors of quay transfer operation in a container terminal, which affected the productivity performance. It tried to overcome the shortcoming of previous studies. Quay transfer operation is one of the operation systems in container terminal, which is affected by many factors and also affected other operations. The delays of the operation will slow down the handling performance and increase the handling time and cost. Hence, an extensive observation and survey activities were done in Malaysian container terminal. The data obtained from relevant respondents that involve in operation. The initial result showed that waiting for prime mover ‘often’ occurred on quay transfer operation. Delay of quay crane and prime mover break downs ‘moderately’ delay the operations. However, waiting for game plan ‘seldom’ affected the operation. Therefore, this study concluded that the handling equipment is the main cause of delay in quay transfer operation in a container terminal.

This paper studied the key delays factor of container yard for a container terminal. It explored the key delays factor that affected the operating performance of container yard operation. Hence, a survey is conducted and analyzed by SPSS. Descriptive analysis, normality test and reliability test are used to analyze and display the result. The initial result showed that rubber tyred gantry crane, turning for 90o and waiting for prime mover are often happened during the container yard operation. As a conclusion, the handling equipment is the main cause of the delays factor.

The article is devoted to the technology of carrying of scrap metal on coasters. Scrap metal, being the cargo, possesses characteristics, which should be taken into consideration by navigator at ship loading. The peculiarity of such category of cargo is relatively serious stowage factor. The pile of scrap metal contains various metal components and items of different shape, size and weight. The observations during the voyage have allowed the determination of the following fact: when grab tears some scrap metal off the pile, it destroys or straightens the parts of the cargo that have lain affected by the pressure forces, and while being loaded into the hold, they may change shape and size. This phenomenon is noticed, when the cargo consists of spring products, wire, tin plates and deformed sheet metal. At present to reduce the loss of the space of the hold at the loading of scrap metal the technology of its “compression” with grab, press or other devices is used. The maximum attention should be paid to the process of “compression” as very often it becomes the reason of underloading of the vessel with the scrap metal. At the designing of the coaster vessels for the future fleet the constructive characteristics of the hold are suggested to be reviewed. The possibility to install the special moving metal bulkhead should be foreseen. It will allow making this fleet more specialized and adapted for the carrying of two or more kinds of scrap metal, bulk cargo simultaneously. The ship-owners will obtain wider opportunities for the exploitation of the new fleet at different freight markets.

In this work, we use Finite Difference Time Domain (FDTD) method to investigate the underwater acoustic wave propagation problem; in order to understand the acoustic wave propagation properties and determining the effects of the attenuation and absorption for the sound intensity in the sea. The results are presented for calculated Transmission Loss (TL) of propagating acoustic waves in layered underwater acoustic environments by using Finite (FDTD) method. In a first step; the sea environment are modeled as one layered medium before generalizing the resolution to two layered (fluid-fluid and fluid-solid) medium. The sea surface and the sea bottom are considered to be planar surfaces. The discretized acoustic wave equations are used in the algorithm of the FDTD method and Perfectly Matched Layer absorbing boundary condition is applied to eliminate numerical reflections from the ends of the grid .Two cases are discussed (Taking account of absorption and attenuation).The good performance of this method is validated with the results of BELHOP program and by comparison with the analytical method.

This paper introduces a general outlook of the chemical tanker market and examines the performance of chartering contracts over the period 2008 to 2013. The number of the liquid chemical cargoes has increased enormously since at the early days, the tanker market was expressing only for carriage of petroleum products. As long as the number of the carriage of chemical cargoes by sea are growing up rapidly, the study aim is to clarify peculiar and main characteristics of these tankers. Although, the big part of these chemical cargoes are extremely dangerous to the environment as well as to the life of the seafarers, it may be considered as a small risk due to the very high standards required regarding safety. Apart of the technical point view, the chemical tanker market is forecasted and expected to recover and improve in/after 2014. The main evidence for this theory is that declining fleet growth, shrinking tonnage growth and increasing seaborne trade. Due to these influences, the market gives positive forecast for its short and near future. However, the chemical products market is still weaken enough and presently demand is still shaky, but due to the limited order books, it could be considered as a positive sign in medium period. Nevertheless, the fleet is still in overcapacity and expectations for improving is at the end of 2014 or later on. The purpose of this paper is to study on the present market and strive to forecast the future chemical tanker market situation

The challenge for the container terminals now is to serve fewer but very large calls. The large cargo quantities to be handled in a short period of time are a challenge for the whole chain from ship to gate. The newly build terminals (greenfield terminals) should have lower environmental impact and high rate of automation and energy efficiency. Therefore terminal and process automation has been steadily gaining ground over the last decade and are unalterable part of today’s container terminal. Automation is a credible option offering new possibilities for operational control and visibility with reduced operating costs and enhanced service excellence. The choice for terminal concept and building of terminal operation system especially in greenfield terminals influence for the future extension of the terminal. Both mainly depend on the size of vessels, which are planned to anchorage at the terminal berth and on expected cargo flow through the terminal for certain period of time.

The ship incidents are related to the loss of human life, significant damage to the marine environment and loss of load. They depend on hydro-meteorological conditions, the density of ship traffic, and the condition of the hull and skills of the officer of the watch. The convention STCW sets various requirements regarding mandatory learning and training of navigators for obtaining the relevant knowledge and skills. Despite of modern technologies for facilitating of navigational watch the number of collisions did not decline. The last IMO bulletin reports that more than 90 percent of collisions are resulted from the human factors: initiated by human error or associated with human error as a result of inappropriate human response. This fact put a question for applying appropriate methods for teaching and training of seafarers in COLREG. The paper propose innovative method for understanding, application and testing of COLREG of navigational officers.

The IMO’s Maritime Safety Committee at its 86th session from May 26 to June 5, 2009 approved new regulations, on which is written that all merchant ships engaged on international voyages are obliged to be fitted with ECDIS(Electronic Chart Display and Information System) schedulely to the middle of year 2018 as the main means for navigation for working with maritime Electronic Navigational Charts (ENC). Therefore United Kingdom Hydrographic Office issued new Admiralty publications, related to implementation, operation and service of ECDIS, and to content, used symbolic and way for making corrections of Electronic Navigational Charts. The Hydrographic Office also made important changes in the content of some existing publications, which deserve to be discussed in this article. After 2012 the exterior design of all Admiralty maritime publications has been changed. This fact shows clearly that comes one new stage in the publication activity of the United Kingdom Hydrographic Office.

The work entitled “The hardness of superficial layers obtained through electrical sparking with hard carbide electrodes and soft materials”, presents the research done by the author in regards hardness increase of superficial layers obtained through impulses electrical discharges. This increase appears because of the thermal effect of pulsed discharges. The aria of material which is under the deposited layer is subjected to a pronounced heating followed by rapid cooling by taking over the heat from the base material. In this way occurs a hardening of metallic material located in close proximity to superficial layer deposited.

The paper presents our work in elaboration and testing of laboratory stand for frequency control of permanent magnet synchronous motors (PMSM). These motors are increasingly finding application in ship electric drives.