Journal of ETA Maritime Science

266-279

Authors: Ludfi Pratiwi BOWO, Masao FURUSHO

Human error plays a vital role in causing maritime accidents. This paper presents the analysis of human factors in 52 grounding accident reports of ships greater than 10,000 GT retrieved from 11 national investigation boards. In this study, the categorization of error-producing conditions (EPCs) from the Human Error Assessment and Reduction Technique (HEART) methodology to 4M (Man, Machine, Media, and Management) framework, EPC–4M was carried out. This study aims to categorize the EPCs to the 4M framework to better explain these other factors that relate to human factors. There were 18 EPCs in man factors, 3 EPCs in machine factors, 1 EPC in media factors, and 16 EPCs in management factors. Three types of generic tasks were obtained in this grounding analysis, and 259 relevance EPC–4M were acquired. EPCs related to management factors were the primary causes of such accidents. The average human error probability for these cases was around 55%.

294-303

Authors: Mahmut MOLLAOĞLU, Umur BUCAK, Hakan DEMİREL

In recent years, the concept of sustainability has come to the forefront as a requirement of strategic management in ports. The safety component which has an important place in the social dimension of sustainability, is very valuable in terms of minimizing occupational accidents at the port area. In order to take precautions against the threat of occupational accidents, understanding the risks causeing occupational accidents are as important as knowing how these accidents occur. The aim of this study is to identify risks in port area that cause Occupational Health and Safety (OHS) violations and to reveal prominent risks as a result of expert reviews. Fuzzy AHP method is employed to analyze priority perception of the experts. Accordingly, risks; ‘Overconfidence and Disengagement’, ‘Inter-Department and In-Department Communication Gap’, ‘Lack of Attention’, ‘Failure to Take Required Precautions during Repair and Maintenance’ have come into prominence in comparison to other factors. It can be concluded that human factor and communication level have vital role to provide OHS in port area.

318-331

Authors: Utku Cem KARABULUT, Yavuz Hakan ÖZDEMİR, Barış BARLAS

Bu çalışmada, çeşitli antifouling boyaların hidrodinamik performanslarını incelemek için kullanılabilecek bir hesaplamalı akışkanlar dinamiği (HAD) yaklaşımı sunulmaktadır. Düz bir levhanın etrafında gelişen, Reynolds sayısı 2,8×106 ve 5,5×106 olan akışları modellemek üzere, zamandan bağımsız zaman ortalamalı Navier Stokes (RANS) denklemleri çözülmüştür. Yüzey pürüzlülüğünün etkileri, sınır tabakanın logaritmik yasa bölgesindeki hız profilinde aşağı kayma olarak modellenmiştir. Tam ölçekli bir gemiye ait sürtünme direnci sonuçlarını tahmin etmek üzere Granville’nin benzerlik yasasından faydalanılmıştır. Sonuçlar daha önceki deneysel ve sayısal çalışmalar ile uyum içerisindedir.

344-360

Authors: Pelin BOLAT, Gizem KAYİŞOĞLU

Cybersecurity awareness has become an important issue in maritime transportation as well as in other sectors. In this paper, after analyzing maritime cybersecurity literature, it is aimed to understand the factors of antecedents and consequences of cybersecurity awareness in maritime domain by taking Turkish Maritime Sector as a case study. Structural Equation Modeling is used for understanding the factors by validating a questionnaire data from 211 maritime employees who graduated from the Department of Marine Transportation Management Engineering and Marine Engineering in Turkey. It is found that (a) education is a significant factor in enhancing the maritime cybersecurity awareness of employee’s and their attitudes towards cybersecurity; (b) cybersecurity incidents or experiences significantly influence employee’s cybersecurity awareness and their behavior; (c) maritime cybersecurity awareness significantly affects secure user behavior. In addition, results showed that rules and policies with information sharing do not have any significant effect on cybersecurity awareness and on the development of secure employee behavior.

212-226

Authors: Ali DOĞRUL

Submerged bodies are commonly used in many fields such as scientific researches, military and commercial applications. Especially in military applications, submarines have a significant role as a silent and deterrent vehicle. Contrary to popular belief, submerged bodies also operate in shallow depth that free surface effects come into play. This causes the visual identification of submarines while protecting them from sonar detection. This study focuses on the investigation of free surface effects on submarine hydrodynamics moving forward in different depths. The numerical calculations have been conducted at different Reynolds numbers ranging from 1.5x107 to 3.5x107 for both bare and appended forms of DARPA Suboff. A commercial CFD solver has been used to solve URANS equations with k-ε turbulence model. The numerical approach has first been verified and validated with the available experimental data. Later, the numerical results have been discussed in terms of total resistance, resistance components and free surface deformations. It has been concluded that the submergence depth has a significant role on resistance components for depth Froude number larger than 0.7 and the appendages have little effect on free surface deformations in all depths.

242-251

Authors: Ferdi ÇAKICI

In this study, the parametric roll motion for the benchmark container ship form C11 is investigated by using the second generation stability criteria, which were intensively studied by IMO (International Maritime Organization). According to the IMO regulations, vulnerability criteria range between 1 and 3. While level 1 is only dependent on ship geometry and speed, level 3 is required to perform direct stability assessment with reliable robust software. The application of level 1 is considerably easy yet it is extremely conservative. Therefore, in the present study, level 2 application is performed that is less conservative than level 1 and easier than level 3. Parametric roll motion is analysed based on GM variation technique. Based on C2 assessment procedure which is calculated as an average of values of different Froude numbers and wave directions, it is found that the benchmark hull C11 was not vulnerable for the parametric roll resonance.

101-115

Authors: Kadir ÇİÇEK

During the last 20 years, regulatory enforcements regarding with the protection of marine environment have been significantly increased. Especially, starting from 1 January 2010 a new regulation, consisting of waste water treatment plants in ships and new effluent limits, took effect. The new limits comprise a stricter review of prior limits. The strict reduction in the effluent limits for the treated wastewater discharged from ships intimates International Maritime Organization (IMO)’s intention to provide more severe control on wastewater discharges and to demand on installation wastewater treatment system that meet international requirements. Furthermore, the new limits constitute a further challenge for the manufacturing companies specified in design and manufacturing of waste water treatment systems. To way out from these points, this study focuses on development a knowledge-based expert system for selection of appropriate shipboard wastewater treatment system. Within this scope, the study proposes a hybrid approach combining AHP and TOPSIS under fuzzy environment. The three most commonly preferred shipboard wastewater treatment system types are examined and evaluated in terms of various design, operation and environment criteria.

127-136

Authors: Şakir BAL

This paper addresses the skew effects (a significant geometric property) of marine propellers on cavitation phenomenon numerically. DTMB 4381, 4382, 4383 and 4384 model propellers with different skew values have been chosen to investigate the cavity patterns on the blades under open water conditions. A lifting surface method has been applied for both non-cavitating and cavitating propellers. Numerical results (nondimensional thrust and torque coefficients, efficiency values and cavity patterns on the blades) have been validated with experimental results. It has been found that the present numerical method is accurate and reliable for predicting the hydrodynamic performance of both non-cavitating and cavitating propeller under open water conditions. It has also been found that under certain conditions the skewed blades of the propeller can cause lesser cavity patterns and improve the propeller performance.

151-163

Authors: Hakan DEMİREL

For all areas where operational activities exist, human error possibilities are of critical importance. In this sense, maintenance, management and monitoring of all components in ships powered by gas turbine systems is a condition that must be observed. At this point, the importance of human impact is great and plays a critical role. In this study, the probabilities of human error on the 14 critical faults described in the literature for gas turbine components are calculated by the CREAM method in the sense of expert opinions. The results clearly indicate the importance of human impact on faults, and guide the technical personnel to be employed on board ship during the operation. This study provides the basis for further studies in this area.

179-191

Authors: Murat Selçuk SOLMAZ , Alparslan BAŞKAYA , Atilla SAVAŞ , Mehmet AKMAN

Artan enerji talebi, akaryakıt fiyatları ve fosil yakıtlardan kaynaklanan olumsuz çevresel etkiler, yenilenebilir ve sürdürülebilir enerjiye olan talebi artırmaktadır. Bu nedenle, rüzgâr ve güneş enerjileri günlük hayatta kullanılabilir hale gelmiş ve bu tür sistemlerin verimliliği konusunda çalışmalar hızlanmıştır. Denizcilik sektöründe de benzer bir durum yaşanmış ve yakın zamanda yenilenebilir enerji gemiler için popüler hale gelmiştir. Bu çalışmada, yakıt tüketimini ve çevre kirliliğini azaltmak amacıyla çalışma zamanının çoğunu demirde ya da iskelede geçiren bir barca rüzgâr ve güneş enerjisini kaynak olarak kullanan yenilenebilir hibrit bir enerji sistemi kurulmuştur. Kurulan sistem HOMER yazılımı ile optimize edilen konfigürasyonlarla mukayese edilmiştir. Sonuçlara göre, hibrit sistemin gemide kullanılmasıyla hesaplarda dikkate alınan süreçte yakıt tüketiminde ve emisyonlarda yaklaşık %39 oranında azalma sağlanmıştır. Sistemin geri ödeme süresi ise yaklaşık iki yıl olarak hesaplanmıştır.

3-15

Authors: Bekir ŞAHİN

Voyage planning is of significance considering the oil consumption, time and safety factors. Determining the proper route after considering multiple convergent factors synchronously is one of the most important subjects in ship management that requires special expertise. The purpose of this paper is to develop a fuzzy analytic hierarchy process (FAHP) extended version of Dijkstra algorithm, and investigate the most prior routing problem in maritime environment. In the literature, there exist many Dijkstra applications but these studies lack of multiple decision makers, consistency control of decision matrices and multiple criteria, which can either be cost or benefit. In this model, subjective judgments and personal experience directly involve in the decision-making process. The proposed FAHP extended Dijkstra algorithm (hereafter FAHP-Dijkstra) improves the capabilities of handling the vague criteria in the presence of fuzziness. This study aims to provide some benefits of oil consumption, time and safety to manned or unmanned ships by presenting a novel route optimization algorithm.

33-41

Authors: Murat AYYILDIZ, Ahmet Ziya SAYDAM, Murat ÖZBULUT

In this study, 2-D wave making characteristics of a submerged hydrofoil has been investigated in a numerical fashion. Experimental data available for different depths of submergence and flow velocities have been compared to the results obtained by a commercial RANS CFD code and an in-house SPH code. The capabilities of the numerical approaches in terms of capturing the free surface deformation have been assessed. At high Froude numbers, the induced wave profiles have been observed to exhibit an unsteady nature by both numerical methods. The pressure contours obtained from the numerical analysis have also been compared with each other. It has been seen that the agreement between the results of the well-established RANS method and recently progressing SPH technique is encouraging for further development.

51-63

Authors: İlkyaz İLDEŞ, Aysu GÖÇER

The increasing importance of marketing services has led services industries to pursue ways of providing better services and improve customer satisfaction in a competitive marketplace. Knowing what can be promoted and what customers consider in choosing the service provider are important factors in a strategic marketing plan. Recognizing core competences with customer expectations and perceptions is undoubtedly the best tool for success. While services marketing has been studied for many services industries, logistics, particularly customs services, is rarely addressed. Exploiting services quality and perception scales, this qualitative study applied content analysis to semi-structured interviews to explore the marketing criteria of customs service providers from a dyadic perspective within businessto- business (B2B) services. Marketing criteria for customs services were categorized as company, personnel, and service-oriented. Three genuine dimensions were created in accordance with their relevance to the service provider company, employees working in the service provider company and the service itself. The results reveal that customs services marketing criteria taken into consideration by customers for service provider choice can be different when compared to other services within a B2B environment. This study contributes to services marketing regarding customs services by comparing the factors of logistics services quality and perception literature.

79-96

Authors: Murat YORULMAZ

Örgüt içindeki temel unsurlardan biri olan insan kaynağı, örgütleri amaçlarına ulaştıran en etkili ve önemli kaynaklar arasındadır. Dolayısıyla insan kaynağının iyi yönetilmesi örgütlerin başarısının da ön koşuludur. Bu nedenle de çalışanların örgütlerine ve işlerine yönelik tutum ve davranışlarının anlaşılması ve yönetilmesi önemli bir olgu olarak kabul edilmektedir. Bu çalışmanın amacı, yöneticilerin yakından ilgili olduğu örgütsel tutum ve davranışlardan; iş tatmini ile örgütsel vatandaşlık davranışlarının, bireysel iş performansına olan etkisini, feribot ve deniz otobüslerinde çalışan gemi adamları örnekleminde incelemek ve gemi adamlarının çalıştıkları bölümlere göre, söz konusu örgütsel tutum ve davranışlarda anlamlı farklılıklar olup olmadığını ortaya çıkartmaktır. Anket yöntemiyle yapılan çalışmada 726 gemi adamından elde edilen verilerin analizi sonucunda, aralarında anlamlı ilişkiler bulunan iş tatmini ve örgütsel vatandaşlık davranışının, bireysel iş performansını pozitif yönde etkilediği ve iş tatmini ile iş performansı arasındaki ilişkide örgütsel vatandaşlık davranışının kısmi ara değişken etkisinin olduğu tespit edilmiştir. Diğer taraftan güverte, makine ve yardımcı hizmetli sınıfı gemi adamları arasında, örgütsel vatandaşlık davranışları ve iş performansı açısından istatistiksel anlamda anlamlı farklılıklar olduğu saptanmıştır.