Academic literature on the topic 'PROPELLER SHAFTS'

The propeller shafts are the structural components that require increased attention. The results of studying the damage of propeller shafts are presented in accordance with the safety requirements (a case of the river vessels). It is shown that residual stresses greatly impact the reliability and operability of the shafts becoming a damaging factor. The residual stresses occur due to surfacing the propeller shaft by ST35 steel with SV-08A welding wire. There is considered the possibility of determining the magnitude of residual stresses by the acoustic method in the surfacing. To estimate stresses the phenomenon of acoustoelasticity was used: the dependence of the elastic waves propagation velocity on the magnitude of the acting stresses. The process of determining the acoustoelasticity coefficients was carried out using standard samples (in accordance with GOST1497). Samples modeling surfacing were manufactured and tested. Metallographic studies were carried out to assess the influence of the material composition of the propeller shaft on the structure and strength properties of the propeller shafts. The influence of the structure on the amount of residual stresses was evaluated. It has been inferred from the tests results that the speed of elastic waves depends on the residual stresses. The results of the work can be used in production conditions for the control of products made of 35 steel with surfacing. In conclusion, the proposed method can be used to determine the residual stresses directly on the propeller shafts in operation conditions during the appropriate maintenance of ships.

Tapered interference fits, which can transfer large torques, are widely used in the connection design for propeller hubs and shafts of large vessels. In this paper, a model was developed to study the influences of torques, rotational speeds and tapers on the tapered interference fit between a propeller hub and a shaft. Using the classic elastic plane stress theory, the exact solutions of the radial stresses, tangential stresses and radial displacements of the propeller hub and shaft are derived. Then the calculation method of the magnitude of the tapered interference fit was presented. Finally taking a screw propeller system as an example, the above solutions were calculated using the numerical method. The results show that improving the stress distribution of the propeller hub is an effective approach to increase the connection strength and torque transmission capacity. If the rotation speed has to be considered, the stress and displacement would be increased significantly due to the centrifugal force. The present analytical solutions are expected to be useful in the structure design of tapered interference fits for propeller hubs and shafts.

Propeller shaft, also known as propeller shaft is the most important component to any power transmission application; automotive propeller Shaft is one of this. A propeller shaft is a mechanical part that transmits the generated torque by a vehicle's engine into motive force which is usable to propel the vehicle. Substituting composite structures for metallic which is structures has many advantages because of higher specific stiffness and strength of composite materials. This work deals with the conventional replacement of steel propeller shafts with fiberglass epoxy composite propeller shaft for an automotive application. The parameters of design were optimized with the objective of minimizing the weight of a propeller shaft. The design optimization also improves the performance of propeller shaft. Present work deals with FEA analysis of composite shaft with different degree of orientation of glass fibers. It includes the modeling of shaft in CATIA. The meshing and boundary condition application will be carried using Hypermesh, Fatigue analysis of composite shaft will be carried out using ANSYS.

Small vessels operating in coastal waters are susceptible to propeller failure because of the entanglement of marine debris. Secondary accidents such as the injury of divers may also occur when removing entangling material. Rope cutters are devices used to prevent marine litter from entangling the propeller of small ships. However, installing rope cutters on propeller shafts might affect the working of the propeller. In this study, three-dimensional simulations were performed to investigate the effect of a rope cutter on flow characteristics behind the propeller. The Computational fluid dynamics (CFD) models were validated by particle image velocimetry (PIV) experiments performed in a rope cutter performance testing tank. The study results showed that the installation of a rope cutter on the propeller shaft led to an insignificant reduction in water flow velocity magnitude behind the propeller. Additionally, the effects of the rope cutter on the reductions of thrust (0.87%) and torque (0.76%) of the propeller were also negligible. However, it is very interesting to note that rope cutter installation resulted in a lower vortex formation, leading to a significant reduction in the turbulence intensity behind the propeller by 27.12%, 37.50%, and 47.29% at 100, 150, and 200 rpm propeller speed, respectively. Based on the study results, it can be concluded that rope cutters help to reduce propeller entanglements without significantly affecting the propeller’s working.

The ship propulsion complex is considered as a torsion system with distributed parameters, consisting of flywheels (cylinder compartments, propeller) connected by shafts. Shafts can be weightless (only rigidity) or have distributed parameters. Contemporary container ships have a shaft line 120 meters long with a power of 86 MW. Such shafting is reasonable to consider as a shaft with the distributed parameters and to take into account the forces arising at an emersion and an immersing of the propeller screw, accompanied by wave effects. Also, the influence of the regulator on the condition of the shaft is considered. It was concluded that about 70 forms should be used (two of them are used). A calculation scheme and a mathematical model are proposed that allow to perform the calculations of the torsion system as a system with distributed parameters. Exposure (exit from the water) of the propeller is accompanied by a decrease in torque on it to almost zero. This condition can last several seconds and is accompanied by a decrease in temperature of the gases entering the turbine of the turbo-charging unit (low fuel supply at almost the same rotation speed). The turbo charging unit at the same time reduces its rotation speed, which leads to a drop in the pressure of the purge air. Immersion of the propeller is accompanied by a sharp increase in torque on the propeller. The speed controller gives the maximum fuel taking into account restrictions. The diesel speed begins to decrease, and the purge air pressure rises. If about 70 forms (using two) are used in the calculations arising from non-stationary torsional vibrations, then you can get a wave running along the shaft shaft both from the propeller and from the diesel engine. These waves interact with each other and lead to a three-fold increase in torque in the propeller. A rational mode of operation of the speed controller is proposed, in which several outbreaks are skipped during the immersion of the propeller. For short shafts, the delay in the regulator may be sufficient. For long, you need to take additional measures. We can conclude that when calculating non-stationary oscillations, the use of about 70 forms (using two) and the organization of the delay of the speed controller with a sharp increase in the load on the propeller.

At present the Cut-stern Kolek Boats of local fishermen at Kaoseng Community on the Coast of Songkhla Lake have a high rate of shaft failure. Consequently, the fishermen have spent lots of money on maintenance program of repairing shafts for a few years. Besides, the repairing cost, each time of the failure also causes water pollution from the leakage of grease. The incomplete transmission of power leads to engine overloading and fuel wasting. The investigation of the high failure rate of propeller shafts which were major machine component in power transmission illustrated the failure in normal fracture caused by the mechanisms of metal fatigue. Using the welding repair by shield metal arc welding process did not give the satisfied outcome because it created the short service life of reused propeller shafts after repairing. This research was aimed to study the metal fatigue behavior of long tail shafts in the Cut-stern Kolek boats and introduce the new method of welding repair process to prolong their service life. The experiment revealed that specimens resulted from the new welding repair process and the conventional one possessed different service life. The new process used the flux core which arc welding can prolong the service life of the shafts of boats more than 1.6 times of using the conventional method which is the electric welding by flux core arc welding. The research result will be extended to fishermen, in order to encourage them to become a part of sustainable inshore fisheries.

The damage to the propeller shaft, a principal mechanical component in the power transmission system of Boats makes engines work harder than normal attributed to less transmission efficiency. Operating boats with the damaged propeller shaft increases the rate of fuel consumption per distance and cost of fishing which affects income of coastal fishermen. The result of a preliminary survey of Boats at Kaoseng Community revealed that the service life of the damaged propeller shafts caused by the fatigue failure would be repaired by shield metal arc welding process. The statistical analysis showed that the useful life depended on fatigue endurance limit of welding surface. When they were back to be used again. The objective of this research was to study the fatigue life of hardfacing surface by solid wire. The method of this research included (a) building up the hardfacing surface (b) forming specimen from hardfacing surface and (c) finding out the fatigue life by fatigue testing machine base on ASTM E739-91 standard. The results of this research indicated that hardfacing surface by solid wire could not receive fatigue stress exceed 500 MPa. The propeller shafts after being repaired will have very short service life, which is not feasible in engineering economy.

This study presents the sizing calculation and the FEM analysis of the propeller shaft for three different operating modes. The propeller shaft has the role of supporting the engine and transmitting its rotating motion and is the most requested element in the structure of the shaft line. In scenario 1, a "fixed support" type constraint is applied at one end and the maximum torque given by the motor at the other end is applied to lock the propeller. Than to simulate scenario 2, apply the maximum thrust force to the propeller at one end, and the "fixed support" constraint will be inserted at the end of the engine. And the 3 th scenario was the operating of propulsion system in normal mode. Comparing the results from the simulation of the three scenarios, it is observed that the maximum values recorded for displacement, equivalent elastic strain and equivalent stresses were recorded at the engine operation under normal conditions. In conclusion, although the scenarios were a bit exaggerated, the propeller shaft withstood the efforts, falling within the limit of elasticity. This demonstrates that the calculation method of propeller shafts is correct, and safe, as long as their size is not oversized.

Tapered interference fits can avoid the influence of keyways on the parts strength and transfer large torques. In this paper, a model was developed to study the influence of the taper on the interference fit between a propeller hub and a shaft. Using the classic elastic plane stress theory, the exact solutions of the radial stresses, tangential stresses and radial displacements of the propeller hub and shaft are derived. Then the calculation method of the magnitude of the tapered interference fit was presented. Finally taking a screw propeller system as an example, the above solutions were calculated by using the numerical method. The results show that the taper plays a key role in the interference fit. Improving the stress distribution of the propeller hub is an effective approach to increase the connection strength. The present analytical solutions are expected to be useful in the structure design of tapered interference fits for propeller hubs and shafts.

Volvo Construction Equipment’s driveline development department initiated this thesis work. It was calculated for two students working for 20 week period of time, which equals 30 hp each. The reason for Volvo CE to start the cooperation was the large number of variance of companion flanges and propeller shafts generating additional work for several departments within Volvo. The problem statement consisted of questions, which should result in information about the number of variants and combinations of propeller shafts and companion flanges used; the reason for the quantity of variants and what factors are affecting the choice of propeller shafts and companion flanges. They should also give answers to how article reduction can be implemented and what recommendations can be given to Volvo for the future. Using a Gantt chart as a planning tool helped the working process to progress in a structured way. Different methods of data collection were done to secure the problem understanding. Tools such as a literature review, function diagrams, and interviews were used to complete the data collection. Co-workers from the purchasing department and the part number reduction team were interviewed. Besides the in-house contact an opportunity was given to interview the suppliers during visits at their factories. Computer software was used as a resource of confirming information and mapping currently used components. The mapping process resulted in interesting findings, which were further researched. Together with the information from the interviews, reasons for the variety of used components were clarified. To deepen the problem understanding a more detailed variation mapping was made, showing what driveline components were generating most variants of companion flanges. The findings made and the recommendations received from the suppliers were unitized in a best case scenario. The questions from the problem statement were analyzed and answered. The recommendations given regarding to Volvo Construction Equipment’s propeller shaft program included guidelines for modularization. The success of modularization is based on among other factors, on particular documentation, continuous communication and close cooperation with the suppliers. This report can be defined as the first step towards a modularized propeller shaft program for Volvo CE’s haulers and wheel loaders.

Федосенко, М. М. Технологічне підготовлення заготівельного виробництва вилок карданних валів : випускна кваліфікаційна робота : 131 "Прикладна механіка" / М. М. Федосенко ; керівник роботи О. П. Космач ; НУ "Чернігівська політехніка", кафедра технологій машинобудування та деревообробки. – Чернігів, 2021. – 108 с.
У кваліфікаційній роботі магістра на основі сформульованих завдань здійснено технологічне підготовлення заготівельного виробництва вилок ковзання карданних валів. В конструкторському розділі запропоновано удосконалення конструкції попереднього штампа для створення сприятливих умов формування кованки. Запропоновано модернізацію ковочного пакету, що полягає в розміщенні поряд з ковочними штампами обрізного блоку. В технологічному розділі розроблено технологічний процес виготовлення нижньої вставки попереднього рівчака та технологічний процес виготовлення кованки вилки ковзання. В організаційному розділі проаналізовані організаційні аспекти технологічного підготовлення виробництва, здійснено організаційне проектування робочого місця коваля-штампувальника. В заключних розділах роботи наведено розрахунки техніко-економічної ефективності проектних розробок. Запропоновані інженерні рішення з питань охорони праці.
In the master's qualification work, on the basis of the formulated tasks, the technological preparation of procurement production of sliding forks of cardan shafts was carried out. In the design section, it is proposed to improve the design of the previous stamp to create favorable conditions for the formation of the forge. The modernization of the forging package is proposed, which consists in placing an edging block next to the forging stamps. In the technological section the technological process of manufacturing the lower insert of the previous stream and the technological process of manufacturing the fork of the sliding fork were developed. In the organizational section the organizational aspects of technological preparation of production are analyzed, the organizational design of the workplace of the blacksmith- puncher is carried out. The final sections of the work provide calculations of technical and economic efficiency of project development. Engineering solutions on safety were proposed.

This degree project has been made in cooperation with engineers working for GM Engineering/Saab Automobile AB in Trollhättan. The given name by Saab for the project is “Fuel efficiency improvements in All Wheel Drive(AWD)-system”. The main tasks of this thesis work were to investigate the size of the power losses in different parts on the propeller shaft, to design a computer program that calculates

coordinates and angles on a propeller shaft and to investigate the possibilities to put together a simplified formula that calculates the natural frequencies on a propeller shaft.

The main parts of this report are a compilation of the theory about AWD and mostly about the parts on the propeller shaft, and also a description of the developed computer program called Propeller Shaft Calculator. This report doesn’t concern power losses in the different joints because there were no such general equations to be found. The most common way to calculate the power losses inside a joint is to do tests were the power loss is measured at different angles, torque and speed and then use that data to put together an approximated equation.

Most of the work on this project has been on theory studies and on programming. The main result of the project is the program Propeller Shaft Calculator.

Propeller Shaft Calculator is a program that is designed in Microsoft Excel. All the menus are programmed in the visual basic editor in Excel. The program is supposed to be used as a help while designing new propeller shafts.

Propeller Shaft Calculator can calculate all the coordinates, lengths, angles and directions on a propeller shaft. It also calculates natural frequencies, plunge, estimated power loss on the second shaft and angles in the joints. In the program you can choose to do calculations on four different configurations of propeller shafts but can quite

easy upgrade the program with more choices.

Basically the program works like this:

First you choose the right propeller shaft in the main menu. Then you fill out the indata sheet with coordinates, lengths, material data and so on. As you type in the input data the output data will appear in the out-data sheet next to the in-data. Every propeller shaft has also a calculations sheet were more detailed calculations can be

found.

The program also has a built in help function and a warning function that lights a warning sign next to the values if they are outside the limits.

Utilisation de la technique d'activation en couches superficielles. Formation du radioelement cobalt 56 par reaction nucleaire. Etude du profil de concentration et mesure in situ d'usure et d'ecaillage (cas des pompes a carburant). Aspects metallurgiques. Application a l'industrie aeronautique

MIG Welding had been widely used in the industry since decades for welding purposes due to its higher weld deposition rate, Ease of use, weld quality and Longer pass welding capability. These all features of this welding process makes the process most prefered welding process for the welding of propeller/Drive shaft. MIG has been proven as the easiest of all the welding processes that uses arc. In automobile sector, its had been widely used. The process uses continuously fed electrode to form the weld bead and joint formation. The process becomes more robust and efficient when it is automated and robots are inherited with the welding process. The usage and combination of robots with MIG Welding makes it robust but it needs to be optimized and process parameter like welding current, welding voltage, gas flow rate must be of such value that prevents any kind of weld defects to be formed over the weld bead. The most major issue that occurs while welding of propeller shafts is improper weld penetration and pin holes. The main aim of this research was to find the optimized value of all the weld parameters with the help of Taguchi design using minitab software and look for any other types of defects while welding and to rectify them and make the process as robust as possible. Addition of automation in any process makes it free from human errors that may occur.As robots can perform repeatative tasks more efficiently we just have to teach them what they have to do and they have to do that. MIG welding when combined with the robot can perform welding at same point without any deviation in position and weld parameters like arc length. To maintain arc length to be constant in MIG welding is almost impossible for any human being which directly effects the weld quality and penetration. An effort was undertaken to study the effects of using robotic arm for welding gun and effects of various process parameters over the weld bead. When non optimized parameters were used for the welding process there we have seen various defects in the final product.

碩士
華梵大學
機電工程研究所
96
This essay is talking about the effects of each component exercising while simulating the equal speed of Rezppa Type universal joint used on the propeller shaft. The simulating method is to tear apart of the equal speed of Rezppa Type propeller shaft and use the Solid Words 3D drawing software to build the appearance. Then use CAE analysis software ADAMS to set up the parameter of each component and condition while exercising. Set up three different speed *1000rpm*, *2000rpm*, *3000rpm* to run the simulating with actual practicing.Through the simulation, we can understand the effects between Rezppa Type propeller shaft and steel ball while exercising.We can realize better the character of propeller shaft after the ADAMS simulation.

碩士
國立海洋大學
造船工程學系
85
This paper is aimed to study the performance of the propeller under different cavitation numbers at inclined shaft condition, and to compare the performance between the New-Section propeller and the Newton-Rader propeller. In order to calculate the effective thrust and the real efficiency for the craft, the horizontal and vertical forces which are both created by the propeller at inclined shaft are measured. When the inclined shaft angle is 8 degrees and the advance coefficient is near the propeller design point, the measrued vertical force is about 40% ~ 50% of the shaft thrust. And, the efficiency of the propeller at 8-degree shaft inclination is significantly less than that of the propeller with horizontal shaft. The experiment also shows that the efficiency of the New-Section propeller is greater than that of the Newton-Rader propeller at inclined shaft condition regardless cavitation numbers. In addition, the "Unsteady Propeller Lifting-Surface Theory" is applied to calculate the vertical force produced by the propeller at inclined shaft condition. Due to the simple mathmatical model about wake in propeller theory, the computational results are much lower than the measured values.

碩士
國立高雄海洋科技大學
輪機工程研究所
94
The object of this thesis is to study the vibration behaviour of the propulsive shafting system induced by a rotating marine propeller carrying single or multiple eccentric concentrated masses. To this end, the entire propulsive shafting system is firstly represented as a three-degree-of-freedom torsional-and-lateral-coupled vibration system. Then, the expressions for total kinetic energy and total potential energy of the entire propulsive shafting system are derived. Next, based on the theory of Lagrange’s equations, the equations of motion of the entire propulsive shafting system are derived and the mass matrix, damping matrix, stiffness matrix and external force vector of the entire vibrating system are determined. Finally, the forced vibration responses of the propulsion shafting system are obtained by solving the last equations of motion with Newmark direct integration method. Some factors closely relating to the current research topic, such as mass, total number and distribution of eccentric concentrated mass, etc, are investigated. From the numerical results, it is found that the influence of eccentric mass(es) of the propeller on the vibration characteristics of the propulsive shafting system is significant.

Nationalism: Past as Prologue began as a single volume being compiled by Ad Akande, a scholar from South Africa, who proposed it to me as co-author about two years ago. The original idea was to examine how the damaging roots of nationalism have been corroding political systems around the world, and creating dangerous obstacles for necessary international cooperation. Since I (Bruce E. Johansen) has written profusely about climate change (global warming, a.k.a. infrared forcing), I suggested a concerted effort in that direction. This is a worldwide existential threat that affects every living thing on Earth. It often compounds upon itself, so delays in reducing emissions of fossil fuels are shortening the amount of time remaining to eliminate the use of fossil fuels to preserve a livable planet. Nationalism often impedes solutions to this problem (among many others), as nations place their singular needs above the common good. Our initial proposal got around, and abstracts on many subjects arrived. Within a few weeks, we had enough good material for a 100,000-word book. The book then fattened to two moderate volumes and then to four two very hefty tomes. We tried several different titles as good submissions swelled. We also discovered that our best contributors were experts in their fields, which ranged the world. We settled on three stand-alone books:” 1/ nationalism and racial justice. Our first volume grew as the growth of Black Lives Matter following the brutal killing of George Floyd ignited protests over police brutality and other issues during 2020, following the police assassination of Floyd in Minneapolis. It is estimated that more people took part in protests of police brutality during the summer of 2020 than any other series of marches in United States history. This includes upheavals during the 1960s over racial issues and against the war in Southeast Asia (notably Vietnam). We choose a volume on racism because it is one of nationalism’s main motive forces. This volume provides a worldwide array of work on nationalism’s growth in various countries, usually by authors residing in them, or in the United States with ethnic ties to the nation being examined, often recent immigrants to the United States from them. Our roster of contributors comprises a small United Nations of insightful, well-written research and commentary from Indonesia, New Zealand, Australia, China, India, South Africa, France, Portugal, Estonia, Hungary, Russia, Poland, Kazakhstan, Georgia, and the United States. Volume 2 (this one) describes and analyzes nationalism, by country, around the world, except for the United States; and 3/material directly related to President Donald Trump, and the United States. The first volume is under consideration at the Texas A & M University Press. The other two are under contract to Nova Science Publishers (which includes social sciences). These three volumes may be used individually or as a set. Environmental material is taken up in appropriate places in each of the three books. * * * * * What became the United States of America has been strongly nationalist since the English of present-day Massachusetts and Jamestown first hit North America’s eastern shores. The country propelled itself across North America with the self-serving ideology of “manifest destiny” for four centuries before Donald Trump came along. Anyone who believes that a Trumpian affection for deportation of “illegals” is a new thing ought to take a look at immigration and deportation statistics in Adam Goodman’s The Deportation Machine: America’s Long History of Deporting Immigrants (Princeton University Press, 2020). Between 1920 and 2018, the United States deported 56.3 million people, compared with 51.7 million who were granted legal immigration status during the same dates. Nearly nine of ten deportees were Mexican (Nolan, 2020, 83). This kind of nationalism, has become an assassin of democracy as well as an impediment to solving global problems. Paul Krugman wrote in the New York Times (2019:A-25): that “In their 2018 book, How Democracies Die, the political scientists Steven Levitsky and Daniel Ziblatt documented how this process has played out in many countries, from Vladimir Putin’s Russia, to Recep Erdogan’s Turkey, to Viktor Orban’s Hungary. Add to these India’s Narendra Modi, China’s Xi Jinping, and the United States’ Donald Trump, among others. Bit by bit, the guardrails of democracy have been torn down, as institutions meant to serve the public became tools of ruling parties and self-serving ideologies, weaponized to punish and intimidate opposition parties’ opponents. On paper, these countries are still democracies; in practice, they have become one-party regimes….And it’s happening here [the United States] as we speak. If you are not worried about the future of American democracy, you aren’t paying attention” (Krugmam, 2019, A-25). We are reminded continuously that the late Carl Sagan, one of our most insightful scientific public intellectuals, had an interesting theory about highly developed civilizations. Given the number of stars and planets that must exist in the vast reaches of the universe, he said, there must be other highly developed and organized forms of life. Distance may keep us from making physical contact, but Sagan said that another reason we may never be on speaking terms with another intelligent race is (judging from our own example) could be their penchant for destroying themselves in relatively short order after reaching technological complexity. This book’s chapters, introduction, and conclusion examine the worldwide rise of partisan nationalism and the damage it has wrought on the worldwide pursuit of solutions for issues requiring worldwide scope, such scientific co-operation public health and others, mixing analysis of both. We use both historical description and analysis. This analysis concludes with a description of why we must avoid the isolating nature of nationalism that isolates people and encourages separation if we are to deal with issues of world-wide concern, and to maintain a sustainable, survivable Earth, placing the dominant political movement of our time against the Earth’s existential crises. Our contributors, all experts in their fields, each have assumed responsibility for a country, or two if they are related. This work entwines themes of worldwide concern with the political growth of nationalism because leaders with such a worldview are disinclined to co-operate internationally at a time when nations must find ways to solve common problems, such as the climate crisis. Inability to cooperate at this stage may doom everyone, eventually, to an overheated, stormy future plagued by droughts and deluges portending shortages of food and other essential commodities, meanwhile destroying large coastal urban areas because of rising sea levels. Future historians may look back at our time and wonder why as well as how our world succumbed to isolating nationalism at a time when time was so short for cooperative intervention which is crucial for survival of a sustainable earth. Pride in language and culture is salubrious to individuals’ sense of history and identity. Excess nationalism that prevents international co-operation on harmful worldwide maladies is quite another. As Pope Francis has pointed out: For all of our connectivity due to expansion of social media, ability to communicate can breed contempt as well as mutual trust. “For all our hyper-connectivity,” said Francis, “We witnessed a fragmentation that made it more difficult to resolve problems that affect us all” (Horowitz, 2020, A-12). The pope’s encyclical, titled “Brothers All,” also said: “The forces of myopic, extremist, resentful, and aggressive nationalism are on the rise.” The pope’s document also advocates support for migrants, as well as resistance to nationalist and tribal populism. Francis broadened his critique to the role of market capitalism, as well as nationalism has failed the peoples of the world when they need co-operation and solidarity in the face of the world-wide corona virus pandemic. Humankind needs to unite into “a new sense of the human family [Fratelli Tutti, “Brothers All”], that rejects war at all costs” (Pope, 2020, 6-A). Our journey takes us first to Russia, with the able eye and honed expertise of Richard D. Anderson, Jr. who teaches as UCLA and publishes on the subject of his chapter: “Putin, Russian identity, and Russia’s conduct at home and abroad.” Readers should find Dr. Anderson’s analysis fascinating because Vladimir Putin, the singular leader of Russian foreign and domestic policy these days (and perhaps for the rest of his life, given how malleable Russia’s Constitution has become) may be a short man physically, but has high ambitions. One of these involves restoring the old Russian (and Soviet) empire, which would involve re-subjugating a number of nations that broke off as the old order dissolved about 30 years ago. President (shall we say czar?) Putin also has international ambitions, notably by destabilizing the United States, where election meddling has become a specialty. The sight of Putin and U.S. president Donald Trump, two very rich men (Putin $70-$200 billion; Trump $2.5 billion), nuzzling in friendship would probably set Thomas Jefferson and Vladimir Lenin spinning in their graves. The road of history can take some unanticipated twists and turns. Consider Poland, from which we have an expert native analysis in chapter 2, Bartosz Hlebowicz, who is a Polish anthropologist and journalist. His piece is titled “Lawless and Unjust: How to Quickly Make Your Own Country a Puppet State Run by a Group of Hoodlums – the Hopeless Case of Poland (2015–2020).” When I visited Poland to teach and lecture twice between 2006 and 2008, most people seemed to be walking on air induced by freedom to conduct their own affairs to an unusual degree for a state usually squeezed between nationalists in Germany and Russia. What did the Poles then do in a couple of decades? Read Hlebowicz’ chapter and decide. It certainly isn’t soft-bellied liberalism. In Chapter 3, with Bruce E. Johansen, we visit China’s western provinces, the lands of Tibet as well as the Uighurs and other Muslims in the Xinjiang region, who would most assuredly resent being characterized as being possessed by the Chinese of the Han to the east. As a student of Native American history, I had never before thought of the Tibetans and Uighurs as Native peoples struggling against the Independence-minded peoples of a land that is called an adjunct of China on most of our maps. The random act of sitting next to a young woman on an Air India flight out of Hyderabad, bound for New Delhi taught me that the Tibetans had something to share with the Lakota, the Iroquois, and hundreds of other Native American states and nations in North America. Active resistance to Chinese rule lasted into the mid-nineteenth century, and continues today in a subversive manner, even in song, as I learned in 2018 when I acted as a foreign adjudicator on a Ph.D. dissertation by a Tibetan student at the University of Madras (in what is now in a city called Chennai), in southwestern India on resistance in song during Tibet’s recent history. Tibet is one of very few places on Earth where a young dissident can get shot to death for singing a song that troubles China’s Quest for Lebensraum. The situation in Xinjiang region, where close to a million Muslims have been interned in “reeducation” camps surrounded with brick walls and barbed wire. They sing, too. Come with us and hear the music. Back to Europe now, in Chapter 4, to Portugal and Spain, we find a break in the general pattern of nationalism. Portugal has been more progressive governmentally than most. Spain varies from a liberal majority to military coups, a pattern which has been exported to Latin America. A situation such as this can make use of the term “populism” problematic, because general usage in our time usually ties the word into a right-wing connotative straightjacket. “Populism” can be used to describe progressive (left-wing) insurgencies as well. José Pinto, who is native to Portugal and also researches and writes in Spanish as well as English, in “Populism in Portugal and Spain: a Real Neighbourhood?” provides insight into these historical paradoxes. Hungary shares some historical inclinations with Poland (above). Both emerged from Soviet dominance in an air of developing freedom and multicultural diversity after the Berlin Wall fell and the Soviet Union collapsed. Then, gradually at first, right wing-forces began to tighten up, stripping structures supporting popular freedom, from the courts, mass media, and other institutions. In Chapter 5, Bernard Tamas, in “From Youth Movement to Right-Liberal Wing Authoritarianism: The Rise of Fidesz and the Decline of Hungarian Democracy” puts the renewed growth of political and social repression into a context of worldwide nationalism. Tamas, an associate professor of political science at Valdosta State University, has been a postdoctoral fellow at Harvard University and a Fulbright scholar at the Central European University in Budapest, Hungary. His books include From Dissident to Party Politics: The Struggle for Democracy in Post-Communist Hungary (2007). Bear in mind that not everyone shares Orbán’s vision of what will make this nation great, again. On graffiti-covered walls in Budapest, Runes (traditional Hungarian script) has been found that read “Orbán is a motherfucker” (Mikanowski, 2019, 58). Also in Europe, in Chapter 6, Professor Ronan Le Coadic, of the University of Rennes, Rennes, France, in “Is There a Revival of French Nationalism?” Stating this title in the form of a question is quite appropriate because France’s nationalistic shift has built and ebbed several times during the last few decades. For a time after 2000, it came close to assuming the role of a substantial minority, only to ebb after that. In 2017, the candidate of the National Front reached the second round of the French presidential election. This was the second time this nationalist party reached the second round of the presidential election in the history of the Fifth Republic. In 2002, however, Jean-Marie Le Pen had only obtained 17.79% of the votes, while fifteen years later his daughter, Marine Le Pen, almost doubled her father's record, reaching 33.90% of the votes cast. Moreover, in the 2019 European elections, re-named Rassemblement National obtained the largest number of votes of all French political formations and can therefore boast of being "the leading party in France.” The brutality of oppressive nationalism may be expressed in personal relationships, such as child abuse. While Indonesia and Aotearoa [the Maoris’ name for New Zealand] hold very different ranks in the United Nations Human Development Programme assessments, where Indonesia is classified as a medium development country and Aotearoa New Zealand as a very high development country. In Chapter 7, “Domestic Violence Against Women in Indonesia and Aotearoa New Zealand: Making Sense of Differences and Similarities” co-authors, in Chapter 8, Mandy Morgan and Dr. Elli N. Hayati, from New Zealand and Indonesia respectively, found that despite their socio-economic differences, one in three women in each country experience physical or sexual intimate partner violence over their lifetime. In this chapter ther authors aim to deepen understandings of domestic violence through discussion of the socio-economic and demographic characteristics of theit countries to address domestic violence alongside studies of women’s attitudes to gender norms and experiences of intimate partner violence. One of the most surprising and upsetting scholarly journeys that a North American student may take involves Adolf Hitler’s comments on oppression of American Indians and Blacks as he imagined the construction of the Nazi state, a genesis of nationalism that is all but unknown in the United States of America, traced in this volume (Chapter 8) by co-editor Johansen. Beginning in Mein Kampf, during the 1920s, Hitler explicitly used the westward expansion of the United States across North America as a model and justification for Nazi conquest and anticipated colonization by Germans of what the Nazis called the “wild East” – the Slavic nations of Poland, the Baltic states, Ukraine, and Russia, most of which were under control of the Soviet Union. The Volga River (in Russia) was styled by Hitler as the Germans’ Mississippi, and covered wagons were readied for the German “manifest destiny” of imprisoning, eradicating, and replacing peoples the Nazis deemed inferior, all with direct references to events in North America during the previous century. At the same time, with no sense of contradiction, the Nazis partook of a long-standing German romanticism of Native Americans. One of Goebbels’ less propitious schemes was to confer honorary Aryan status on Native American tribes, in the hope that they would rise up against their oppressors. U.S. racial attitudes were “evidence [to the Nazis] that America was evolving in the right direction, despite its specious rhetoric about equality.” Ming Xie, originally from Beijing, in the People’s Republic of China, in Chapter 9, “News Coverage and Public Perceptions of the Social Credit System in China,” writes that The State Council of China in 2014 announced “that a nationwide social credit system would be established” in China. “Under this system, individuals, private companies, social organizations, and governmental agencies are assigned a score which will be calculated based on their trustworthiness and daily actions such as transaction history, professional conduct, obedience to law, corruption, tax evasion, and academic plagiarism.” The “nationalism” in this case is that of the state over the individual. China has 1.4 billion people; this system takes their measure for the purpose of state control. Once fully operational, control will be more subtle. People who are subject to it, through modern technology (most often smart phones) will prompt many people to self-censor. Orwell, modernized, might write: “Your smart phone is watching you.” Ming Xie holds two Ph.Ds, one in Public Administration from University of Nebraska at Omaha and another in Cultural Anthropology from the Chinese Academy of Social Sciences, Beijing, where she also worked for more than 10 years at a national think tank in the same institution. While there she summarized news from non-Chinese sources for senior members of the Chinese Communist Party. Ming is presently an assistant professor at the Department of Political Science and Criminal Justice, West Texas A&M University. In Chapter 10, analyzing native peoples and nationhood, Barbara Alice Mann, Professor of Honours at the University of Toledo, in “Divide, et Impera: The Self-Genocide Game” details ways in which European-American invaders deprive the conquered of their sense of nationhood as part of a subjugation system that amounts to genocide, rubbing out their languages and cultures -- and ultimately forcing the native peoples to assimilate on their own, for survival in a culture that is foreign to them. Mann is one of Native American Studies’ most acute critics of conquests’ contradictions, and an author who retrieves Native history with a powerful sense of voice and purpose, having authored roughly a dozen books and numerous book chapters, among many other works, who has traveled around the world lecturing and publishing on many subjects. Nalanda Roy and S. Mae Pedron in Chapter 11, “Understanding the Face of Humanity: The Rohingya Genocide.” describe one of the largest forced migrations in the history of the human race, the removal of 700,000 to 800,000 Muslims from Buddhist Myanmar to Bangladesh, which itself is already one of the most crowded and impoverished nations on Earth. With about 150 million people packed into an area the size of Nebraska and Iowa (population less than a tenth that of Bangladesh, a country that is losing land steadily to rising sea levels and erosion of the Ganges river delta. The Rohingyas’ refugee camp has been squeezed onto a gigantic, eroding, muddy slope that contains nearly no vegetation. However, Bangladesh is majority Muslim, so while the Rohingya may starve, they won’t be shot to death by marauding armies. Both authors of this exquisite (and excruciating) account teach at Georgia Southern University in Savannah, Georgia, Roy as an associate professor of International Studies and Asian politics, and Pedron as a graduate student; Roy originally hails from very eastern India, close to both Myanmar and Bangladesh, so he has special insight into the context of one of the most brutal genocides of our time, or any other. This is our case describing the problems that nationalism has and will pose for the sustainability of the Earth as our little blue-and-green orb becomes more crowded over time. The old ways, in which national arguments often end in devastating wars, are obsolete, given that the Earth and all the people, plants, and other animals that it sustains are faced with the existential threat of a climate crisis that within two centuries, more or less, will flood large parts of coastal cities, and endanger many species of plants and animals. To survive, we must listen to the Earth, and observe her travails, because they are increasingly our own.

Full scale seakeeping trials are rare, especially planing hull and are in general focused in studying bottom pressures, accelerations and vibrations. In this paper, a comprehensive description of the experimental setup and analysis of full scale seakeeping trials propulsion data of a 65 ft planing pleasure yacht is presented. Torque and rpm have been measured on both propeller shafts during seakeeping trials in mild sea conditions, along with hull motions and accelerations. Correlations between hull motions and propulsion data are discussed, both in the time and frequency domain. Further tests on a shaft sample have been carried out in order to validate its mechanical properties and hence quantitative results regarding shaft torque. The main novelty of the present work lays in a detailed analysis of the propulsion system response of a planing pleasure yacht in mild weather conditions.

In this experiment, the work piece is electrochemically machined which finds its applications in brine heaters, heat exchangers, propeller shafts, and pumps. The process is carried out using sodium chloride electrolyte and copper beryllium wire as tool electrode which is heat treated in three different methods which are annealing, quenching, and normalizing. The response parameters like theoretical and experimental metal removal rate have been measured and studied by varying machining parameters like voltage, frequency, concentration of electrolyte, and duty cycle. Based on the values obtained from the experiment, it is found that quenched tool electrodes have better machining capabilities than the other heat-treated tool electrodes and untreated tool electrodes.

The aim of the research is to develop an azimuthing contra-rotating propeller for commercial applications with a power of 2000 kW. The thruster system is designed especially to be installed on high speed crafts (HSCs) for passenger transport with a cruising speed of about 35–40 knots. The topic is very useful because the azimuth thruster solutions currently do not find commercial applications in naval units for passenger transport. The latter are heavy, not very efficient from a hydrodynamic point of view and suitable for maximum cruising speed of about 18–20 knots. The study is interesting because among the advantages that these solutions provide are the possibility of transmitting very high torques and to guarantee a much longer life cycle. In more detail, the propulsion is realized by using a C-drive configuration, with a first mechanical transmission realized by using bevel gears mounted in a frame inside the hull, and a second transmission realized by bevel gears housed in a profiled hull at the lower end of a support structure. In the profiled hull will be installed the shafts of the propellers, in a contra-rotating configuration. In order to optimize the system before its industrial use, a close power loop test bench has been studied and designed to test high power transmissions. The test configuration allows to implement a back-to-back connection between two identical azimuthing contra-rotating propellers. Moreover, the particular test bench allows to size the electric motor simply based on the dissipated power by the kinematic mechanisms. Since the efficiency of these systems are very high, it is not necessary to use large electric motors, thus managing to contain the operating costs of the testing phase. The most significant disadvantage is the need to have two identical transmissions with consequent increase in installation costs. Through the back-to-back test bench it was possible to study the increase in efficiency compared to traditional systems.

Nickel-Aluminum bronze (NAB) (UNS 63000) main propulsion shafts are employed in AVENGER Class minesweepers due to the alloy’s strength, corrosion resistance, and low ferromagnetic signature. The US Navy sought additional sources of sustaining the Fleet with refurbished shafts using weld repair processes followed by Post-weld Temper Annealing (PWTA) heat treatment to mitigate dealloying corrosion. This paper describes the high level of technical cooperation and information sharing among Navy, shaft repair facility, and supplier metallurgists and engineers needed to successfully develop, test, and qualify three essential weld repair processes and supporting inspection and PWTA procedures for NAB shafts.

Marine propeller shafts, like most power transmission shafts, are fatigue-loaded components. Because of the corrosive environment, they operate in, a marine propeller shafts' corrosion fatigue strength may the limiting factor in its design. The life of a fatigue-loaded mechanical component is dependent on the tensile stresses it is subjected to in service. If effective tensile stresses acting on a shaft could be reduced. Service life could be extended Shot Peening is a mature, developed procedure that has been proven successful in raising fatigue strength and retarding Stress Corrosion Cracking. A rather simplified approach explaining how and why it works in addressing the very complicated subject of fatigue is presented here. Particularly in the aerospace and automotive industries, its successful applications are well documented The practical suggestion on how it could be applied in providing extended service lives for marine propeller shafts is attempted in this paper. Several relevant case studies conducted by other researchers are presented.

This paper reports substantially enhanced fatigue and corrosion-fatigue lifetimes of propulsion shaft materials, 23284A steel and 23284A steel with In625 weld overlay cladding, as a result of shot or laser peening. Glass reinforced plastic (GRP) coatings and Inconel claddings are used to protect shafts against general corrosion and corrosion pitting. However salt water leakage penetrating under a GRP can actually enhance pitting leading to crack initiation and growth. Fatigue coupons, untreated and with shot or laser peening were tested, including with simultaneous salt water immersion. Controlled corrosion of the surfaces was simulated with electric discharge machining (EDM) of deep pits enabling evaluation of fatigue and corrosion-fatigue lifetimes. Results specifically show high energy laser peening (HELP) to be a superior solution, improving corrosion-fatigue resistance of shaft and cladding metal, reducing the potential for corrosion pits to initiate fatigue cracks and dramatically slowing crack growth rates. At a heavy loading of 110% of the 23284A steel yield stress and with 0.020 inch deep pits, laser peening increased fatigue life of the steel by 1370% and by 350% in the corrosion-fatigue testing.

PTFE (Poly-Tetra-Fluoro-Ethylene) is a well-known bearing material used to provide low friction for water-lubricated shafts. Partial arc design bearings are attracting keen interest due to reduce friction, since it develops a hydrodynamic film even in water lubrication. However, the application of both PTFE material and a partial arc design is limited to small bearings, because conventional PTFE partial arc bearings are manufacture in ring form and PTFE rings have strict limitation in size. In this paper, a newly developed, PTFE partial arc bearing for large water-lubricated tail-shafts is outlined. Friction, wear and deformation properties of the new bearing are described. In addition, wear life prediction is proposed for the PTFE partial arc bearing.

Det Norske Veritas has developed an alternative design-verification methodology for shafting systems for ship propulsion. This methodology satisfies all shaft fatigue safety requirements and gives a better basis for cost optimizations than other established codes. For two-stroke powered propulsion plants, such as discussed in this paper, saved costs are basically related to the choice of torsional vibration damper size and more slender shafts resulting in simpler shaft alignment and less bearing problems. Shaft design examples based on the Del Norske Veritas methodology and essential elements of the theory are presented.

Early propeller shafts operated in water lubricated lignum vitae bearings and used stuffing boxes as seals at hull penetrations. The bearings, however, required regular replacement, and the stuffing boxes not ideal as seals. Around 60 years ago, new seals were developed that allowed the use of white metal bearings for propeller shafts. The technology offered a controlled environment for the bearings, which extended bearing lifespan. The weakness of the system, though, has always been the effectiveness of the seals, which must leak some amount in operation for cooling. Yet leakage into the stern tube causes oil emulsion and often catastrophic bearing failure, while leakage from the stern tube results in pollution. With even the latest sealing technologies, that weakness continues; sea pollution remains a possibility and is becoming ever-more intolerable, as witnessed by increased environmental awareness and legislation. Improvements in water lubricated material technologies have resulted in greater choice of materials, which can now offer improved and predictable bearing wear life. Progression of sealing technology has also replaced the previous troublesome packing glands. Classification Societies Rules related to water lubricated propeller shaft bearings are also undergoing revision and extended shaft withdrawal is now possible.

British Columbia Ferry Services Inc. operates five "C" class passenger-car ferries that were delivered in 1976 (3 ships) and 1981 (2 ships). The vessels have a service speed of 19.0 knots, are 457 ft. long, and have a gross tonnage of 6,550 tons. They have a capacity of about 360 cars and 1,500 passengers. Their route varies from Vancouver-Vancouver Island-Sunshine Coast, with up to 9 round trips per day. The vessels have a double-ended single screw propeller configuration. Each of the controllable pitch propellers are driven by one or two diesel engines rated at 5,930 HP, through single reduction gearboxes. The two gearboxes are connected via quill shafts that are concentric with the pinion shafts. The pinion shafts are engaged via clutches at the end of each of the quill shafts. This arrangement enables one or both of the diesel engines to drive either one or both of the propellers. In 1998 a catastrophic failure occurred to the bull wheel on one vessel. The bull gear teeth broke off taking out both pinions. In 1999 the bull gear on another vessel was replaced as a result of fractured gear teeth, found during an inspection. In addition, a number of failures have occurred to both the lineshaft and pinion shaft bearings. An investigation was conducted to determine the source of the failures and the most prudent and economical course of action. To accomplish these objectives a review of the system design and maintenance/failure history was conducted, as well as theoretical modeling and alignment and vibration measurements. It was found that the failures occurred due to misalignment. A realignment program has been undertaken, with the first realignment completed in February 2002. This paper describes the failure investigation and the results of the realignment work conducted.

Market demands and development trends of the past 10 years have lead to an increase of the ship hull bending and simultaneously lowered the flexibility of the propulsion shafts. Optimum large bearing distances and pre-compensation of influences affecting alignment need to be considered for the alignment layout of the propulsion shaft line. Calculations using advanced 3D FE based crankshaft models with elastic bearings and clearance are utilised to evaluate alignment measurement result.

SKF Marine ISC was requested by STX Finland Oy, location Rauma to perform full scale dynamic propulsion shaft measurements on board of the RoPax vessel “Pride of France” in order to solve high shaft support bearing operational temperatures. After modeling the propulsion line with a state-of-the-art CAE software for shaft alignment and vibration calculations and recording of the actual static bearing load and actual static bending stress of the accessible shaft line, during a sea trial, several dynamic measurements like dynamic bending stress, shaft torque and speed, shaft orbit, bearing temperature, vibration and longitudinal shaft movement were measured and recorded. After analysis of the measured and recorded data, following conclusions could be made; Large longitudinal shafts movements were present in operational condition. Measured shaft support bearing temperatures have a linear relationship with measured and calculated bearing load in operational condition, so temperature readings can be used as a condition monitoring tool to calculate bearing load in different operational conditions.

Carbon Fiber Tubes have been used as propulsion shafts for about 20 years and they are finding more and more acceptance. The theory about the design and specification of such tubes has been known for a long time. It has partly been described in the SNAME paper, Propellers/Shafting 97 Symposium in chapter 4 from the same author. This time the broad experience and design philosophy of such complete shaft lines shall be described and explained by using various samples of several successful applications.