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The characteristics of the fore and aft foils at the various angles of attack incorporated with forward velocities have been vulnerable to induce strong nonlinearities to dynamic lift force and ship resistance. Then, a computational simulation is necessarily required to predict their performances in the calm water condition. This paper presents a computational investigation of the hydrofoil ship on predicting lift and ship’s resistance using fluid dynamic (CFD) simulation approach. Several parameters such as Froude numbers and the angle of attacks both of fore and aft foils have been accordingly taken into account. The results revealed that the subsequent increase on angle of attack of fore and aft foils was directly proportional to the lift force and the ship’s resistance. In addition, the lift force of the aft and fore foils with the angle of attacks of 10 degrees and 5 degrees, respectively, resulted in the significant increase of the lift force and the ship’s resistance. However, the subsequent increase of Froude number from 1.382 up to 1.626 has insignificant effect to the lift and the ship’s resistance of the hydrofoil. It can be concluded that CFD simulation is very beneficial to ensure an operational effectiveness of hydrofoil design towards prediction on the lift force and the hydrofoil’s resistance at the preliminary design stage.

A progressive flooding-ingress of water to a compartment of a damaged ship affects the motions of a ship. In this present study, the behavior of the motion of a ferry caused by damaged conditions in waves was investigated through the experimental work. The leakage of compartments was made into several scenarios including one, two, and three damaged compartments, and the damaged ship model was simulated in heading and beam waves. The research results show the one damaged compartment on the engine room (ER) affected extreme stern trim as well as Void No.1 affected extreme bow trim. The two damaged compartments on the water ballast tank (WBT) No.2 and Steering gear room (SGR) resulted in extreme stern trim as well as WBT No.1 and Void No.1 affected extreme bow trim. The heave, pitch, and roll responses on the damaged Void No.1 are higher comparing with the damaged ER. Also, the heave, pitch, and roll responses on damaged SGR and WTB No.2 are higher than Void No.1 and WBT No.1. The peak resonances of heave RAO on bow trim affect higher magnitude than on stern trim. Pitch or roll RAO caused by the increased bow trim or stern trim in head and beam waves has a small magnitude within the response.

The impact pressure induced by slamming can imply physical damage on a ship. The high probability of the slamming impact is on the bow part in the actual sea state. In this present study, the slamming induced pressure on the bow flare of a ship have been investigated through the experiment. The experiment was schemed by the dropping test based on free-falling body in the wave tank, wherein the bow of the ship model was inclined in several impact angles 0° to 30° to the free-water surface. To measure slamming impact pressure acting on the bow flare, the piezoelectric sensors S1, S2, S3, S4 were attached to the bow section and installed on a computer. As the obtained results, the impact pressure on bow flare occurred in a short time duration caused by slamming. The discrepancy of the peak impact pressure between ship model weight of 2.42 kg and 7.29 kg for the impact angle 0° is 70.36% S1, 69.52% S2, 68.97% S3, and 68.34% S4. For the relative impact angle of 30°, the discrepancy is 67.02% S1, 65.73% S2, 58.51% S3, and 48.21% S4. The tendency of the peak pressure coefficient at the sequenced impact points S1, S2, S3, S4 is similar for all impact angles 0°, 10°, 20°, and 30°. The peak pressure coefficient due to the full load condition is highest in the nearest bottom part, and the peak pressure coefficients due to the lightship condition highest in the nearest bottom part caused by the small impact angle.

Designing the form of the ship stern hull could have some impacts on the efficiency of ship propeller and the requirement of the ship speed. Therefore, stern hull form of a ship matched to its propeller and engine power is important consideration in preliminary ship design stage. The main objective of this study is to investigate ship performance by matching the stern hull shape to the propeller diameter and engine power toward high speed. This study was conducted by free running model test and Maxsurf Resistance application. The stern forms were employed U-shape and V-shape. In addition, the fixed pitch propeller (FPP) with three blades was used and the diameter is varied into three sizes 0.032 m, 0.040 m, and 0.048 m. The results show the increase of propeller diameter increases model’s speed for both U-shape and V-shape stern and the effect of the propeller diameter on the speed could be described by using the equations of second-order polynomial. The optimum propeller diameter could be determined taking into account stern hull form, stern shape, tip clearance, and proper speed where then propeller diameter related to draft is given by 0.79T with tip clearance 10%Dp for both U-shape and V-shape. The ship resistances of U-shape stern at Fr 0.221 and V-shape at 0.208 are obtained approximately 89.797 KN and 77.10 KN respectively. Furthermore, the powers of ship for both U-shape and V-shape at those Fr are obtained 904,374 KW and 726,807 KW respectively. Finally, the best stern hull form matched to propeller diameter and engine power is selected and given by U-shape stern.

Most of the traditional wooden boats in Sinjai and Bone Districts were measured using the domestic measurement method, ship owners with sizes

Indonesia Government through the Ministry of Maritime Affairs and Fisheries is holding a fishery boat procurement assistance program of gross tonnage (GT) 5 to 30. In order to be effective investment for the program, a comprehensive study on fishing boat is emphasized to be carried out. This study aims to determine the investment components of a fishing boat with GT of 12, 21 and 30 based on the consideration of the local content, determine the feasibility of fishing boats investment including the local content aspect, and determine the weight of local content for the investment of fishing boat. The investment feasibilty was analysed by using Net Present Value (NPV) and Internal Rate of Return (IRR). In the present results, the three fishing boat sizes of GT 12, 21, and 30 were economic feasibility and suitable in order to support the welfare of fishermen in Sinjai Regency, South Sulawesi Province. The NPV and IRR within 10 years for the fishing boat size of GT 12 are approximately 823 million rupiahs and 77% respectively, 988 million rupiahs and IRR of 54% for GT 21, and 979 million rupiahs and 38% for GT 29. The weight of the local content aspect contributes in average of 81.47% on the investment of the fishing boat wherein the local content includes boat hull buliding, fishing equipment, and labor cost. In addition, the weight of the local content aspect for ship operation is average of 61.88% wherein the local content includes fishermen salary and fishing aggregating device.

Maccini Baji port as minor port is a hub of small islands connectivities in Pangkejene and Kepulauan Regency, South Sulawesi. It has strategic role to serve cargo and passenger ship from not only small islands in Pangkejene and Kepulauan Regency but also from outside such as Papua, Maluku, and Nusa Tenggara Timur. Correspondingly, Maccini Baji port has faced the fluctuated increase of visited ships from 2011 to 2018 based on forecasting result by using stepwise and regression methods and has a good potential to be developed especially for cement cargo. This study describes analysis on port facility performance of Maccini Baji and its development. The research result has shown the berth occupancy ratio (BOR) of Maccini Baji port in 2022 will reach 61%. This has become a primarily point to consider in lengthening berth of Maccini Baji port. Therefore, the port berth of Maccini Baji should be lengthened 272 meters where existing berth length is 225 meters. In addition, basin and anchorage area will be also developed where the dimensions of turning basin will be 6 meters in depth, 121.8 meters in diameters, and its area will be 116 m2. The dimensions of anchorage area will be 6 metres in depth, and 105.9 meters in radius and its area will be 35.21 m2. Based on SWOT analysis, some aspects will be considered to succesfully develop Maccini Baji port such as geographic location, port facility improvement, increas of service capacity and facility efficiency, development of hinterland area, local government participation.

In recent years, the number of shipyards in Indonesia has increased significantly to anticipate the increasing demand and the government policy regarding the Cabotage Principles and Masterplan for Acceleration and Expansion of Indonesia’s Economic Development (MAEIED), and three Archipelagic Sea-Lanes (ASL’s) in Indonesia. However, shipbuilding and ship repair works have been centered in the western part of Indonesia. Therefore, this study aims to develop a potential strategy of shipyards in the eastern part of Indonesia to compete in the current market situation. The Analytical Hierarchy Process (AHP) method was used to model the strategy hierarchy and analyze the weight of sub-criteria as the internal and external factors of the shipyard competitiveness. Then, the Blue Ocean Strategy method was used to analyze the competitiveness strategy. To improve competitiveness, the shipbuilding industries in the eastern part of Indonesia have to focus intensively on reforming and upgrading several internal environment factors such as coordination and response, business network, high skill manpower, and complex ship types building ability. Besides, the shipyards also have to focus on external environmental factors, particularly on five factors that have a high influence on improving competitiveness, namely shipping company partners, networks and partnership with suppliers, government policies, human resource development, and cluster formation of shipyards.

The ferry business has become an important business segment for ship designers, builders and operators. Therefore, many ways have been done in order to increase ferry business through the proper design or converting ships by lengthening. This research is focused on the influences of lengthening a Ro-Ro ferry to hydrodynamics characteristic and loading capacity aspects. Moreover, the ships also are fixed in the same width and draft dimensions. The difference of the Ro-Ro ferries length is indicated by the addition of one column of car space where one column car space is given by car size including distance between car columns spaces which is an increment of every 5.88 meter. The total resistances of Ro-Ro ferries are obtained by ship model experiment in towing tank. There are 4 ship models that are made. The lengthening a Ro-Ro ferry is described into non-dimensional parameter by the ratio of ship length and displacement volume (L/V1/3). The hydrodynamics and the loading capacity of carried car aspects could be described into the ratio of resistance and loading capacity of carried car (RT/SUK) with ship speed. The research result shows that the lengthening of a Ro-Ro ferry affects on total resistance, speed, and loading capacity of carried car. The increase of total resistance is caused by higher residual resistance at high speeds and this is experienced by small length size. Therefore by lengthening the Ro-Ro ferry it could reduce total resistance in the same speed especially the residuary resistance but eventhough lengthening Ro-Ro ferry the effective speed should be considered. In additions, the effective speed for actual ships dimension in the same Rt/SUK 0.05 i.e. B5L10 is about 13.85 knot, B5L11 14.33 knot, B5L12 14.94 knot, and B5L13 15.45 knot respectively.

The location of the beam and the deck girder of the ship can be effect on it is strength especially for the longitudinal strength due to the vertical wave bending moment. The objective of this study is to know the structural response of the ship due to vertical bending moment load on hogging and sagging conditions. The analysis is carried out by using Finite Element Method so-called ANSYSTM. The results shows that the stress occurring on the ship model with deck beam above the deck plate is larger than the ship model with deck beam under the deck plate. When the load with the variated of 0.2 x moment of vertical moment load, there is an increase of stress that occurs both on the deck area about 12% while on the bottom area about 0.98%. This study also conducted a stress comparison by using analysis methods with analytical methods. The results show that by the Stress differences that occur in the structure with the longitudinal deck beam and deck girder above are 14.1% on the deck and 7.1 on the bottom. Whereas in the structure with deck longitudinal deck eam and deck girder under there is a difference of 5.7% on the deck area and 3.5% in the bottom area of the ship. The stress that occur in both models have a difference that is not too far away and still under the permisible stress by the classification society so that both can be applied to the construction of a tanker.

A towed barge is one of the typical sea transportation systems that is basically composed of towing and towed ships connected to each other by a tow rope. During a towing operation exposed to rough sea condition, the risk of collision and breakage of a tow rope may be high and the consequences serious. This paper describes an experimental investigation of a towed barge’s motions in heading waves. The effects of various lengths and the configuration of tow ropes incorporated with various loading conditions of the towed barge have been taken into account. Here, three tow-rope lengths were used, namely 1L, 1.5L, and 2L; meanwhile, the two tow-rope configurations i.e., Straight-Tow (ST) and V-Tow (VT) models were applied and incorporated with 50% and 100% of the loading conditions of the towed barge. Regardless of the tow-rope models of ST and VT, the results revealed that the towed barge’s motion responses were generally proportional to the increase of the towline lengths and the towed barge’s loading conditions. It should be noted here that the VT model with 1L tow rope length in the full loaded condition has less RAO of her heave and pitch motions as compared to the other towing arrangements. Merely, this research investigation provides very useful guidance on a ship towing navigation in waves.

Improving a ship’s stern part couldhelp to reduce greenhouse gases and costs. However, a ship sailing in actual conditions experiences disturbances that can affect its performance. Ship performance is an important aspect of the design process that guarantees ship safety. The heave and pitch motions of an improved fishing boat were predicted numerically by using a hybrid scheme of Eulerian grid-Lagrangian particle, hereinafter improving its stern part and attaching an additional part. The stern part improvement and additional structure attachment affected an increase on the heave amplitude from the ship’s basic form by 5% to 10%. Moreover, the improvement of the stern part in the bottom area contributed to a better heave amplitude than that of the side area. Finally, the pitch amplitude for all forms was relatively small and affected an increase of 5% to 9%, dependent on the form. The improvement had a greater effect on heave motion than pitch.

We have developed an efficient and robust CFD method to compute a strongly nonlinear interaction between wave and ship,such as heave and pitch motions in a severe wave condition, resultant slamming on the surface of a ship and an impact pressure due to green-water phenomena. The proposed method is based on coupling the Eulerian method for fluid phase with the Lagrangian method for solid phase to compute fluid-structure interaction. In this model, two kinds of Lagrangian particles are employed. One is free surface particle located near the free surface to capture a water surface accurately. The other one is SPH particle to compute ship motions in 3D. A fully nonlinear phenomenon with wave breaking is treated on a fixed Eulerian grid with the free surface particles to rebuild density function for capturing an interface between two phases in a filamentary under resolved region. In this study, the proposed model was applied to ship-wave interaction for evaluating of seakeeping of a ship in waves and their results were compared with experimental results and strip theory.

Efek-efek nonlinear interaksi antara kapal dengan gelombang sangat penting dipertimbangkan dalam pendiainan kapal. Mengabaikan efek tersebut dapat berakibat pada kecelakaan kapal. Pada pendesainan kapal, aspek ship response di gelombang sangat penting untuk diperediksi. Banyak kajian gerak kapal menggunakan asumsi pendekatan linear dan sederhana. Pada penelitian sebelumnya, kami telah melakukan simulasi numerik untuk memprediksi gerak kapal Feri di gelombang menggunakan metode computational fluid dynamics (CFD) hybrid Eulerian scheme with Lagragian particle, dimana mempertimbangkan semua penomena yang timbul akibat interaksi antara kapal dan gelombang. Namun, hampir semua metode CFD membutuhkan waktu yang cukup lama untuk menghasilkan suatu data. Sementara pada proses disain kapal dibutuhkan suatu metode yang bisa menghasilkan data yang cepat dan akurat guna pengambilan keputusan. Oleh karena itu pada penelitian ini akan dilakukan pengembangan metode Strip theory dengan mempertimbangkan efek-efek nonlinear. Pengembangan metode ini akan dapat dioperasikan berbantuan komputer dengan menggunakan bahasa pemograman Fortran. Pengembangan metode Strip Theory telah dilakukan. Metode yang dikembangkan tersebut telah diverifikasi dan dapat digunakan untuk mensimulasi dan memprediksi gerak kapal di gelombang. Simulasi ini berdasarkan pada panjang gelombang l meter dan 4 meter serta panjang gelombang 0.5 LWL sampai dengan 2.0LWL. Amplitudo Heaving kapal mulai meningkat dari panjang gelombang 0.6LWL dan menurun pada panjang gelombang 0.7LWL sampai pada 0.8LWL. Pada panjang gelombang 0.9LWL sampai dengan 2.0LWL amplitudo heaving meningkat seiring peningkatan panjang gelombang. Selanjutnya, amplitudo Pitching kapal menurun pada panjang gelombang 0.6LWL, dan meningkat pada panjang gelombang 0.7LWL sampai pada 2.0LWL. Dimana puncak amplitudo Pitching terjadi pada panjang gelombang 2.0LWL. Tendensi RAO Heaving pada kedua tinggi gelombang cenderung sama. Hal ini menandakan bahwa nilai respon gerak heaving cenderung memiliki kenaikan yang linear. Pada kondisi 1.6LWL hingga 2.0LWL memiliki RAO lebih besar dari 1 (satu), hal ini menunjukkan bahwa response gerak heaving kapal lebih besar daripada beban gelombang dengan tinggi gelombang. Kemudian tendensi RAO Pitching pada kedua tinggi gelombang menunjukkan bahwa RAO Pitching semakin naik seiring kenaikan panjang gelombang. Namun, RAO tertinggi terjadi pada 2.0LWL untuk tinggi gelombang 1 meter dan 4 . Penelitian ini masih perlu banyak perbaikan untuk mencapai hasil yang sempurna dan lebih akurat lagi. Untuk menguji keakuratan hasil penelitian, validasi akan dilakukan dengan menggunakan metode lain yang tersedia dan free termasuk aplikasi-aplikasi computational fluid dynamics (CFD). Selain validasi hasil dengan menggunakan metode numerik yang telah dijelsakan sebelumnya maka penelitian ini akan dikembangkan ke depan dengan melakukan eksperimen atau pengujian tarik di tangki percobaan (Towing Tank).