Multihull vessels such as trimaran have been well known to have better transverse stability and can provide wider deck area and have been found to be quite successful when operated as passenger carriers. Trimaran has also been known to produce lower resistance, and hence lower power and less fuel consumption, compared to monohulls. The current research investigates the resistance characteristics of a displacement trimaran at various spacing configuration (up to S/L = 0.5) and Froude numbers (up to 0.27) together with the analysis of seakeeping characteristics. The investigation was carried out experimentally using tank test belongs to ITS and numerically using ANSYS-CFX for resistance analysis and ANSYS-AQWA for seakeeping investigation. Final results indicate that there is strong correlation between lower resistance and better seakeeping characteristics and overall, the results are in good agreement with published data.
Department of Naval Architecture and Shipbuilding Engineering, Institute of Technology SepuluhNopember (ITS), Surabaya, Indonesia
Marine renewable energy has potential to play a significant role in the world’s future energy system. Marine renewable energy has attracted many developers and researchers around the world aiming reducing carbon emission and enhancing blue economy. To promote the development of successful marine energy devices, it needs to achieve the reliable conditions for facing aggressive and corrosive marine environment. Corrosion is an important issue in marine environment. Corrosion can cause structural deterioration and product loss in the main component structure of marine energy devices, such as turbine. Corrosion has been studied for many years, and this paper focuses to review about the most possible types of corrosion occur in marine renewable energy device, factor affecting corrosion, method of corrosion identification, and corrosion that occurred in marine renewable energy device. Study work in corrosion of the marine energy is recommended in order to assess failure and increase the lifetime of marine energy device itself.
Department of Ocean Engineering, Faculty of Marine Technology, Institute of Technology Sepuluh Nopember (ITS), Surabaya, Indonesia
Department of Naval Architecture and Shipbuilding Engineering, Faculty of Marine Technology, Institute of Technology Sepuluh Nopember (ITS), Surabaya, Indonesia
The shipbuilding and ship repair industry in Malaysia comprises of designing, building and assembling, repairing and maintaining, transforming and advancement of vessels as well as marine equipment. It is getting larger and always evolve in line with the development of technology such as with the latest technology which is embedded in modular construction. The modular construction approach in building a vessel is a common method nowadays. The latest, Boustead Naval Shipyard (BNS) were entrusted to build 6 Littoral Combat Ship (LCS) for Royal Malaysian Navy (RMN) in BNS in Lumut, Malaysia. One of the advantages for this contract is the technology transfer which also includes the modular construction. Thus, this paper shows the contribution to the modular construction resulting in Malaysia Shipyard. The result can be used for the better understanding of modular construction and its impact on production process in Malaysia, and also improve the technology and method of modular construction.
Faculty of Science and Defense Technology, National Defense University, Malaysia, Kem Perdana Sungai Besi, 57000 Kuala Lumpur, Malaysia
Faculty of Computing and Informatics, Universiti Malaysia Sabah, 87000 F.T. Labuan, Malaysia
It has been almost 40 years since the 1972 International Regulations for Preventing Collisions at Sea known as Colregs were introduced and there have been several amendments to Colregs rules since then until now.
Collision avoidance is believed, in a sense, to prevent groundings, the striking of fixed obstacles and ships colliding. Over the last half-century despite improvements in navigational aids such as ARPA, AIS, ECDIS and attempts to raise the standards of training through various STCW conventions, collisions still occur. Many studies and accident reports indicate that the accidents are caused by either human error or are associated with human error as a result of inappropriate human responses. Collisions commonly represent the majority of these accidents.
This paper does not attempt to examine all Colregs rules, but is concerned with the basic rules that are usually ignored or disregarded, in order to identify the deficiencies in the application of Collision rules at sea. This paper will also touch on the deficiencies in the maritime education and training (MET) navigational officers’ programme that is related to Colregs teaching. This paper will suggest the development of a course with a set of standards and study units for testing the understanding of seafarers in applying the Colregs rules. The standards will be developed from real accident cases while testing the potential navigators’ understanding with real time situations. This would improve the application of the Colregs rules at sea environment..
School of Ocean Engineering, Universiti Malaysia Terengganu, 21030, Kuala Terengganu, Terengganu, Malaysia
One type of wave energy converter is based on the overtopping concept. An example of such device is the multi-reservoir Sea Slot-Cone Generator (SSG) which is based on a simple flat breakwater ramp design. Although it is capable of functioning as both a wave-breaker and wave energy harvester, the SSG still suffers from low performance with 38 percent hydraulic efficiency. This paper presents a numerical study to improve this performance. The present research work considers the use of convex, concave, V-shape and bridge V-shapes front ramp designs. The overtopping phenomena were simulated using Flow 3D CFD software. Results are presented in the form of mean overtopping discharge and expected power output for each of the three reservoirs. The numerical results showed that the highest potential power output is given by the V-Shapes design with 67 percent (56.9 kW) improvement compared to current existing SSG device (34.1 kW) at a wave height of 2.80 meters and wave period of 9.3 seconds.
Marine Technology Center, Universiti Teknologi Malaysia, Malaysia
Faculty of Mechanical Engineering, Universiti Teknologi Malaysia, Malaysia
Faculty of Engineering, Alexandria University, Egypt
Evaluating the performance of floating breakwater for coastal protection inevitably requires reliable approach to adequately capture the dynamic interaction between waves and structure particularly in random waves. This paper presents a prediction on hydrodynamic properties of pile-restrained cylindrical floating breakwater (CFB) using computational fluid dynamics (CFD) simulations. Several parameters are studied in a 1:20 structural model under the influence of random and regular waves with corresponding to relative width (W/L) and relative draft (d/H) of the floating structure associated with South China Sea. The result reveals that the wave absorbing effect of CFB is apparently better for low and high waves with short and long periods by exhibiting higher dissipation coefficient than reflection one. This is attributed to the stiffness effect and inherent damping role of the mesh cage, in particular. The pile mooring CFB satisfactory performs in dissipative manner with satisfactory transmission coefficients for the considered environmental parameters.
The modified form of linear random wave theory, effective node elevation and effective water depth procedures have been introduced as promising way to give better realistic presentations of near surface wave kinematics. There is some evidence from both studies that the wave kinematics results lay between the corresponding values of Wheeler and the vertical stretching methods. In this paper, the effects of different methods of simulating wave kinematics on the structural members (smooth and rough surfaces) are carried out lead to significantly different estimates of the 100-year responses.
Program of Maritime Technology, School of Ocean Engineering, Universiti Malaysia Terengganu, Malaysia
Silicon carbide (SiC) films were deposited on stainless steel (SS), mild steel (MS) and aluminium (Al) from a SiCtargeted in a magnetron sputtering system to produce the amorphous SiC coating. Magnetron sputtering is a Physical Vapor Deposition (PVD) process for deposited material onto substrate by ejecting atom from such SiC and condensing the ejected atom onto SS, MS and Al metals in high vacuum environment. The behavior of the films as corrosion protection barriers in different concentrations of sodium chloride (NaCl) solution in 0.5 M and 1.0 M at different temperatures (30oC and 50oC) were evaluated by electrochemical impedance spectroscopy (EIS) measurements. EIS is powerful technique used to study the electrochemical properties of SiC due to high sensitivity to the presence of pores in the film. Films on SS exhibited a better corrosion resistance than MS and Al. X-ray diffraction (XRD) used for determination of phase identification.
School of Ocean Engineering, Universiti Malaysia Terengganu, 21030 Kuala Terengganu, Terengganu, Malaysia
Large commercial ships used for transportation of liquid cargo are provided with many tanks for storage of liquid cargo during voyage. The cargo loading and unloading process requires close monitoring of the liquid level in these tanks to prevent overflow or spillage. In most ships the liquid level sensing of these tanks is still performed either manually or with the help very rudimentary analog devices which apart from being less accurate are also unreliable giving false readings and often cause of accidents from cargo spill. In this paper the author proposes a simple low-priced microcontroller unit design for tank liquid level monitoring and control. The proposed design has been simulated using the Proteus software and then later implemented and prototype tested in the hardware models. The program was compiled in PIC C Compilers, and programmed into the microcontroller using a programmer for PIC 8-bit microcontrollers. The proposed microcontroller functioned well during simulation and prototype testing.
Metallic materials are the most applicable materials in various industries. They are used due to their excellent mechanical properties. However, they are exposed to the corrosion because the environment contains oxygen, humidity and some other factor. This paper describes about the paint incorporated with organic inhibitor, henna extract. These paints were produced to enhance the property of paint to be anticorrosive paint. Henna extract was chosen as a corrosion inhibitor as it is organic, environmentally acceptable, readily available and renewable source of materials for a wide range of corrosion problems. The extractions were characterized using Fourier Transform Infrared (FTIR). Meanwhile, the inhibitive action of henna extract was investigated through electrochemical technique. The inhibitive effects of henna extract were investigated with percentages of 0, 4, 8 and 10% incorporated into rosin (epoxy) based matrix. The specimens were characterized by electrochemical impedance spectroscopy (EIS) measurement. The morphology study was investigated through surface analysis using scanning electron microscopy (SEM). The inhibition efficiency increases as the concentration of henna extract increased. The results shows that paint 3 have the lowest corrosion rate, 0.001767 mm/yr compared to paint 1 with 0.005148 mm/yr. The inhibitive action of the henna extract is discussed and also proposed as an excellent natural inhibitor for aluminium.
School of Ocean Engineering, Universiti Malaysia Terengganu, Malaysia
School of Fundamental Science, Universiti Malaysia Terengganu, Malaysia
Cryogenic materials such as 9% Ni steel and stainless steel are commonly used in LNG storage tank. However, these materials either are expensive or require costly welding consumables. In order to boost the development of natural gas industry, a more cost effective material should be utilized. High Manganese steel (high Mn steel) is proposed to be used for LNG storage tank in FLNG since it offers lower cost with good strength performance. Hence, this study concentrates on numerical study of the FLNG-ship collision to assess the risk and structure damage of high Mn steel FLNG. Nonlinear FEM is performed on FLNG for selected 5 collision scenarios using LS-DYNA. The outcome of the study shall prove the pertinence of high Mn steel as the material for LNG storage tank construction, in hopes of providing cost-attractive material alternative with competent strength properties.
Graduate School of Engineering Mastership, Pohang University of Science and Technology, Pohang, Republic of Korea
Department of Naval Architecture and Ocean Engineering, Inha University, Incheon, Republic of Korea
Department of Mechanical Engineering (Ocean and Ship Technology), Universiti Teknologi PETRONAS, Perak, Malaysia
Department of Civil and Environmental Engineering (Ocean and Ship Technology), Universiti Teknologi PETRONAS, Perak, Malaysia
