Analisis Perbaikan Stern Tube Poros Propeller Single Screw pada Kapal General Cargo 4192 GT

<p>Dalam proses perencanaan kapal, pada tahap pemasangan poros propulsi di kapal, tentu saja diperlukan penyelarasan yang benar. Kesalahan dapat menyebabkan distribusi beban yang tidak merata pada bantalan, akibatnya menyebabkan abrasi yang tidak normal, kondisi kelebihan beban, kelebihan beban dan kerusakan pada bagian bantalan tertentu, hal tersebut berlaku juga kepada struktur yang mendapat beban statis sebagai tumpuannya. perlunya uji numerik untuk proses analisa terjadinya beban berlebih dalam persiapan reparasi bantalan poros <em>propeller</em> sehingga menunjukan karakter hidrodinamik dan beban yang terjadi ketika bantalan dan poros <em>propeller</em> mulai kontak. Tujuan penelitian ini,menganalisis desain bantalan poros <em>propeller </em>untuk direparasi dan untuk mendapatkan performa terbaik dari sistem kontak antara bantalan dengan poros <em>propeller</em> sehingga merepresentasikan perbandingan kinerja dari <em>propeller</em> sebelum dan sesudah perbaikan. Metode perhitungan dengan metode <em>finite elemen</em> berbasis persamaan matematik merepresentasikan tegangan yang terjadi sesuai karakter material <em>bronze</em> ( AlBr dan CuSn) yang diaplikasikan pada performa bantalan proros <em>propeller</em> kapal tipe <em>general cargo</em> seberat 4192 GT. Hasil analisa menunjukan saat putaran <em>propeller</em> pada rpm mesin yang optimum, tegangan maksimum juga terjadi sesuai dengan hasil percobaan temperatur yang terjadi juga semakin tinggi. Pada beban rpm 525 maka <em>shear stress</em> untuk <em>stern tube</em> material AlBr bernilai 978 Mpa dan pada material SnCu bernilai 948 Mpa. Nilai <em>deflect </em>atau <em>cleareance </em>pada setiap posisi setelah dilakukan perbaikan mengalami peningkatan rata-rata sebesar 24,4 % dari pengukuran awal sebelum dilakukan reparasi. Proses reparasi menunjukan performa yang cukup baik, rata-rata temperatur kerja yang dihasilkan ketika dilakukan pengujian <em>sea trial</em> menurun dari sebelumnya sebesar 7,5%.</p>

The Influence of Price, Service Quality, and Word Of Mouth on the Purchase Decision of PT Daniel Samudra Abadi's Loading and Unloading Services

PT Daniel Samudra Abadi is a company engaged in stevedoring services. The services provided are specialized in products, such as steel (cold rolled steel sheet, steel sheet in coil, steel plate, prime concast steel slab, etc.), pulp, and general cargo. The purpose of this research is to determine the influence of price, service quality and word of mouth on the purchase decision of stevedoring service. The population in this research are consumers of PT Daniel Samudra Abadi who have used service from 2018-2020 period with 31 companies as a sample. Determination of the sample in this research using saturated samples. This research uses multiple linear regression analysis. The results showed that all independent variables, namely price, service quality and word of mouth have a positive and significant effect on the purchase decision of PT Daniel Samudra Abadi stevedoring service.

RETROFITTING OF FLETTNER ROTORS – RESULTS FROM SEA TRIALS OF THE GENERAL CARGO SHIP “FEHN POLLUX”

In 2018, a German- Dutch project consortium under the scientific direction of the Emden/Leer University of Applied Sciences retrofitted and commissioned the latest rotor development of the Eco-Flettner type on the test ship Fehn Pollux of the Leer-based shipping company Fehn Ship Management. Main design features are both upper and lower endplates with large diameter for improved aerodynamic performance and modular manufacturing. The retrofitting concept is groundbreaking in terms of easy transferability to other ships. Upscaling to a significant share of the world merchant fleet could make a substantial and realizable contribution to climate protection in the short term and potentially reduced transport costs in the long term. The most frequently asked question in connection with modern sail drives is about the performance potential and the associated fuel savings. Transparent performance data is required to enable an economic prognosis for the use of Flettner rotors on ships. The Faculty of Maritime Sciences at Emden/ Leer University of Applied Sciences has developed an automatic control and monitoring system for Flettner rotors that also records extensive operating and environmental data. The data shows that all previous assumptions and model calculations are basically correct. With regard to the performance potential, the first series of measurements show even higher rotor forces compared with model calculations. This is a further benefit for Flettner rotor efficiency and could help the technology achieve a breakthrough as a building block for low-emission shipping.

Evaluating technological feasibility of fruit and vegetable transportation by sea between ports of Caspian Sea

The modern process of fruit and vegetable transportation between countries depends not only on geographical, but also on political and economic factors, which makes for searching more efficient and shorter routes. The availability of such a transport opportunity as sea transportation between the ports of the Caspian Sea makes it possible to analyze new routes for the product transportation from Iran, Azerbaijan and other countries to Russia using dry cargo vessels that are currently used as the general cargo vessels. There have been analyzed the new routes for transportation of perishable products in refrigerated containers and assessed the possibility of their transportation on the “Volga” type bulk carriers. The routes “Astara (Azerbaijan) - Moscow”, “Astara - port Alat - port Kuryk - Moscow” have been illustrated. A general arrangement drawing of a “Volga” type dry cargo vessel (project 19610) is presented, the photographs of transporting timber and containers on the decks of dry cargo vessels are given. Calculating the load of the dry cargo ship’s power plant has shown a technical possibility of transporting 16 refrigerated containers on deck of the “Volga” type vessel without changes in the design of the ship’s power plant. Conclusions are made about the need to develop effective cargo transportation by waterways in modern conditions of the loss of traditional Russian suppliers of fruit and vegetable products, about the possibility of additional use of dry cargo ships, as well as the feasibility of developing a backup diesel generator for emergency power supply of deck refrigerated containers in connection with a possible increase in the capacity of the ship power plant.

Ship building design of general cargo vessel using comparator ship method in port route of Jakarta-Makassar-Manokwari

Marine-based industrial development includes several sectors including Sea Transportation Services, Ferry Services, Capture Fisheries, Offshore Oil & Gas, Marine Biological Resources, Marine Tourism, and Energy Conversion, which in general both management and operations require supporting facilities, namely ships. with certain types that can serve these interests. During the current economic recovery period, there need to be concrete and more innovative steps that must be pursued by all parties, both government and private, in order to reduce the time needed to improve the state’s economic condition. Hence, the role of marine potential is very vital to be further developed in the future. The optimization results of the comparison ship obtained the main dimensions of the design vessel, namely: Lbp = 81.19 m, B = 15.00 m, T = 5.50 m, H = 7.00 m, Cb = 0.75, Cm = 0.99, Cw = 0.84 Cpv = 0.89, Cph = 0.76, Fb = 1.50 m, Fn = 0.22, Displacement = 5280.91 tons, Volume = 5131.583 m3, GRT = 3910 tons, Vs = 12 knots, Lwl = 83.22 m. This comparator ship method makes it easy for ship designers with accurate results.

Optimization of the stages of a ship's cargo plan development for shippining of general cargoes

One of the main tasks in stability calculations is to provide the ship with the necessary (optimal) trim whose final value is influenced by the arrangement of cargo on the ship. Today, however, there are rules and requirements but there is no unified approach to developing a cargo plan for a vessel that simultaneously transports various types of general cargo. In order to improve the efficiency of the above calculations, a procedure has been proposed to optimize developing a cargo plan for a vessel carrying heterogeneous general cargoes at the same time, the main idea of which is to distribute consignments on the ship in two stages, taking into consideration the compensating trimming moment. The scheme to develop a cargo plan has been improved by introducing the developed procedure. The results of verification confirmed its effectiveness in practice. Possible deviations of the values for the trim required (optimal) for the voyage from the actual one calculated after the allocation of stocks and consignments of goods have been investigated using an example of the series of developed cargo plans. It should be noted that the value for the trim, required (optimal) and actual, for each individual cargo plan does not differ by more than 8 %. The results reported in this paper give grounds to assert the expediency of their application when developing cargo plans for tramp shipping vessels. The introduction of the procedure could make it possible to effectively load a vessel with the full utilization of both its carrying capacity and cargo capacity. The use of the proposed scheme for developing a cargo plan to transport heterogeneous cargoes would reduce the total time for calculating the stability and strength of the vessel in general

IMPROVING THE DESIGN OF THE SPRING SUSPENSION OF TRAILED VEHICLES

This article presents materials related to the development of a promising design of adaptive tor-sion bar suspension for trailed special and cargo vehicles, both trailers and semi-trailers, designed for the transportation of bulk and general cargo. A number of technical solutions, created at the level of inventions, are proposed, which make it possible to simplify the existing types of spring suspensions, reduce their metal consumption, improve the smoothness of trailed vehicles (TV) and increase their operational reliability due to the operation of suspensions in automatic mode when they overcome micro and macro unevenness of the roadway. Analytical studies were carried out with the development of a design scheme and a methodology for calculating the design of an adaptive torsion spring for static and dynamic strength.

Dampak Penerapan Protokol Covid-19 Terhadap Kinerja di Pelabuhan Hub Internasional: Studi Kasus Pelabuhan Tanjung Perak

Kegiatan bongkar muat barang merupakan faktor penting penentuan kinerja pelayanan kapal di pelabuhan. Pandemi Covid-19 memberikan dampak yang signifikan terhadap pergerakan aktifitas di Pelabuhan. Protokol kesehatan yang sudah ditetapkan WHO untuk meminimalisir dampak covid 19 dengan menggunkan masker, mencuci tangan, dan menjaga jarak. Dengan menggunakan metode regresi linier polinomial didapatkan hasil penerapan protokol kesehatan pada operator sebesar 85% menggunakan masker, 49% menghindari jabat tangan, 39% mencuci tangan, 39% menjaga jarak, 25% menghindari kerumunan dan 10% melakukan penyemprotan disinfektan. Pada kunjungan kapal berdampak pada turunnya kapal bermuatan curah cair mengalami kontraksi -30% pada triwulan I, Curah kering -48% Triwulan III, dan General Cargo -16% pada triwulan III. Sedangkan volume muatan mengalami penurunan yaitu curah cair -14% pada triwulan I, Curah kering -12% Triwulan II, dan General Cargo -54% pada triwulan III. Model persamaan regresi polinomial didapatkan Y= 320 - 9 X1+ 71 X2 - 54 X3 -13 X4 -63 X5 + 6 X6. Dampak pandemi covid-19 berpengaruh secara signifikan terhadap angkutan penumpang, sementara untuk angkutan barang sempat mengalami kontraksi saat awal pandemi dan selanjutnya mengalami peningkatan mendekati normal seperti kondisi pra pandemi.AbstractThe loading and unloading of goods are an important factor in determining the performance of ship services at the Port. The Covid-19 pandemic has had a significant impact on the movement of activities at the Port. The health protocol that has been set by WHO is to minimize the impact of COVID-19 by wearing masks, washing hands, and maintaining distance. Using the polynomial linear regression method, the results of implementing health protocols for operators were 85% using masks, 49% avoiding handshakes, 39% washing hands, 39% keeping distance, 25% avoiding crowds and 10% spraying disinfectants. On ship visits, the impact on ships carrying liquid bulk contracted -30% in the first quarter, dry bulk -48% in the third quarter, and General Cargo -16% in the third quarter. Meanwhile, cargo volume decreased, namely liquid bulk -14% in the first quarter, dry bulk -12% in the second quarter, and general cargo -54% in the third quarter. The polynomial regression equation model obtained Y= 320 - 9 X1+ 71 X2 - 54 X3 -13 X4 -63 X5 + 6 X6. The impact of the COVID-19 pandemic had a significant effect on passenger transportation. In contrast, freight transportation had experienced a contraction at the beginning of the pandemic and subsequently increased to near normal as in pre-pandemic conditions