19.04.2025
THEORY OF MACHINES.

The present file, or e-book, will be greatly appreciated by the people involved with mechanical engineering, including both professionals and the students. The content was prepared by the collective of mechanical engineering experts who shared their knowledge and experience, not only purely technical, but also considering the way of presenting the material.

Their combined efforts have eventually resulted in this brilliant publication. Note that the present volume was computer-based from the beginning, no scanning as such. Meaning, that it is easily searchable and also provided with some additional features for better navigation across sections and throughout the text.

The book is really big, so the authors managed to put it all in a single volume, covering literally all important areas of mechanical engineering, such as the kinetics and kinematics of motion, simple mechanisms, simple harmonic motion, velocity using the instantaneous and relative velocity methods, acceleration, friction, inertia forces, toother gears, and so many others, up to and including automation.

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19.04.2025
SHIPS ON MAPS: PICTURES OF POWER IN RENAISSANCE EUROPE

Before 1375, ships rarely appeared on maps. By 1550, they had become prominent features, depicted across oceans, seas, estuaries, rivers, and lakes in various kinds of maps - ranging from the most extensive to the highly detailed. This dramatic shift can be attributed to broad changes in map-making techniques, an explosion of geographical knowledge, and evolving European perspectives about themselves and their place in the world during the Renaissance.

Understanding the subsequent disappearance of ships from maps in the 18th century involves examining similar underlying factors - shifts in artistic fashion, technological advancements, and new ideas about Europe and the physical universe. To truly grasp the reasons behind the rise and fall of decorative vessel illustrations on maps, one must explore the ideas, representation issues, and the social and economic structures that regulated map production. This inquiry is akin to a long voyage through an array of images - starting from simple, small sketches of the landscape around the mapmaker, to some of the most exquisite works of Renaissance art.

Such explanations highlight the cartographic revolution of the 15th and 16th centuries, reflecting changes in perceptions among thinkers, writers, and policymakers. They also reveal how the practical needs for new knowledge and user demands shaped both the art and function of maps. Maps always simplify a complex world.

They serve as external, physical representations of the earth’s surface—multifaceted, yet inherently limited. Since it is impossible to perfectly replicate the land’s reality, maps are essentially portrayals—likenesses and simplified models. The precise duplication of any geographical setting is unattainable; therefore, maps, like all forms of communication, intentionally fragment and streamline reality to convey understandable information.

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19.04.2025
Land Rigs

Let us spend a couple of minutes on the land-based oil rigs. Yes, most of the materials and information presented herein are related to the offshore units; however, it would make sense to know a bit about how this all started. Just read this short article.

As we know, the very first drilling rigs used were land rigs and were invented and subsequently both in Texas, USA and in Germany just over hundred years ago.

Nowadays, the land-based oil rigs constitute an advanced piece of machinery and when thinking of the amount of engineering and care in manufacturing, racing cars can look a bit sedate.

Land rigs come in all sizes, from small trailer mounted rigs to very large rig systems requiring more than 100 trucks to move. One of the first criteria for design of a land rig is how to move it. If the rig has to move on normal roads, it has to be dismantled to pieces that can be easily be transported by truck and does not exceed axle load restrictions.

In addition to weight limitations, the sizes of equipment that has to be moved will also impose problems and cost. In most countries, there are rules for height and width of goods to be transported on roads. When exceeding these rules, police escort and road and bridge modifications may add significantly to the overall cost of drilling a well.

Rigs dedicated for work in deserts are quite often built without regards for road transport. Some of the EDC, standing for the Egyptian Drilling Company, rigs working in Syria and in Egypt have large wheel assemblies, or moving gears retrofitted so the entire Rig with mast and substructure can move in one piece.

This is quite a reduction in loads to move and makes quite a difference in the time it takes to move the rig. If it takes seven days to move a rig without the moving gear attached it will take approximate sixty hours for the rig move with the moving gear attached.

Land rigs have a distinct advantage over rigs made for working on water, space and weight is not a problem. Contractors build rig sites to suit the rig and the equipment not the other way around. A standard desert foot print for a rig location is 400 ft x 400 ft.

Another advantage is that if a project requires special equipment this can be added to the rig inventory without worrying about deck loads and permissions. Also, note that a rig may require additional mud tanks for a well and this will then be no problem as land locations can be expanded easily enough.

Newer land rigs are also designed for fast rig up and rig down as well as minimizing the impact on the landscape and environment. Drive past a pad of producing wells today and there will hardly be anything to evidence that a big rig and a large rig location has been in use. All that can be seen is a few square meters of concrete where the wellhead is located and safely fenced in.

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16.04.2025
SHIPPING BUSINESS UNWRAPPED

The shipping industry may not be widely known to the public, but it plays a highly significant role in the global economy. This book offers an overview of the shipping business, grounded in microeconomic theories from both institutional and behavioral perspectives, while revealing some of the industry’s hidden facts. Instead of dedicating extensive time to reading numerous books or hiring expensive advisors on fundamental topics, readers can swiftly access key concepts analyzed from multiple angles.

They will enjoy the engaging, story-driven content and discover many surprising truths about this intriguing field. Many people overlook the shipping sector's importance. Although consumers are aware that many of their products originate abroad, they rarely pause to consider the journey—how these goods travel from distant countries to local stores. When they think of ocean-going vessels, they often romanticize stories of shipowners and captains.

In reality, modern shipping is a highly industrialized operation involving a complex network of logistics, countless transactions, multimillion-dollar deals, and billions worth of cargo. The financial side of maritime activities has also evolved, with ships bought and sold as investment assets comparable to stocks, managed by corporate executives, and often involved in speculation using advanced financial instruments. Most notably, the development of maritime transportation and shipping has been a crucial driver of globalization.

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16.04.2025
DESIGNING CATHODIC PROTECTION SYSTEMS FOR MARINE STRUCTURES AND VEHICLES

Cathodic protection is a crucial technique for safeguarding structures and ships from the corrosive impact of seawater. The design of these systems greatly influences the overall lifespan of a structure, with poor designs often incurring significantly higher costs compared to optimized solutions.

Incorrectly designed systems can lead to overprotection, resulting in paint blistering and accelerated corrosion of some alloys; underprotection, which causes structural corrosion; or stray current corrosion affecting nearby structures. The first ASTM symposium dedicated specifically to cathodic protection in seawater was held on November 3, 1998, in Norfolk, Virginia.

The goal of this symposium was to gather and present all relevant criteria and principles for designing both sacrificial and impressed current cathodic protection systems for structures and vehicles in seawater. Due to the complexity of the subject, it was impossible to cover everything in a single day. The papers included in this Standard Technical Publication (STP) are noteworthy because they encapsulate the main philosophies behind seawater cathodic protection system design. The inaugural paper by Hartt introduces the latest method for determining cathodic protection current requirements for marine structures.

Known as the Slope Parameter Approach, this method provides a more precise way to facilitate the formation of calcareous deposits compared to traditional techniques. Recently, this approach has served as the foundation for developing a standard by NACE International. The U.S. Navy has likely created more cathodic protection systems for ships than any other organization.

Recently, the Navy has started utilizing physical scale modeling to accurately position reference cells and anodes, as well as to identify the optimal system size and capacity. The paper by Lucas and colleagues describes the Navy’s methodology for testing these scale models and explains how the results are applied to actual ship designs.

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16.04.2025
SHIPPING LAW BY ROBERT GRIME

It has been quite a long time since the first edition of this book was published. Therefore, the author can confidently state that all the most valuable and constructive criticisms from the initial edition have been incorporated. He feels secure in this claim, as he believes no one will remember the previous shortcomings.

The goal remains unchanged: to present a challenging, complex, yet fascinating area of law in an accessible manner. It is hoped that this approach will benefit both lawyers without specialized expertise who wish to take first steps toward learning, and non-legal practitioners involved in shipping who can gain insight into what lawyers are doing in this field. In addition to updating the content, several sections have been expanded. Notably, Chapter 10 on Marine Insurance—which was embarrassingly brief in the first edition—is now the longest chapter.

This expansion was directly influenced by positive feedback received earlier. The initial chapters have also been reorganized considerably to include discussions on the interaction between international conventions and local laws, as well as the roles of international organizations and national governments. The format remains consistent: footnotes are deliberately avoided, but relevant cases are included within the text as illustrative examples.

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16.04.2025
SHIPS FROM THE WEST

Kearney concludes his remarkable and sophisticated Monarchies of God sequence with "Ships from the West." Newcomers to this expansive saga should certainly begin with the preceding four volumes, as understanding the narrative hinges on prior knowledge. This installment delivers a satisfying resolution to the overarching story. The series’ signature strengths—rich character development, intricate plotting, and a grounded, thoughtful approach to fantasy—are all on display, resembling fantasy reimagined as historical fiction.

Some readers have voiced concerns regarding character deaths and unanswered plot points, notably Bardolin's alliance with the Himerians. However, we believe these elements elevate the book, contributing to its mature tone. The tragic circumstances demand significant losses, and the deaths of beloved figures underscore the scale of the catastrophe. Even seemingly unheroic ends serve to highlight the brutal realities of war.

Regarding unresolved questions, perceptive readers can likely deduce the motivations behind key decisions. Often, implication and nuance surpass explicit exposition. Our primary criticism lies in the narrative’s rushed pacing; the events deserved considerably more space to unfold. Perhaps the author, nearing the end of a lengthy project, felt compelled to swiftly reach the conclusion, a slight drawback but not a fatal one.

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16.04.2025
Drilling Rig Types

Although this section of our website is devoted to the offshore exploration and drilling activities, this short article is here to cover the major types of oil rigs in general.

Oilfield drilling is, when it comes down to bare essentials, a question of “drilling a usable hole” in the ground. And, in turn, usable hole is commonly characterized by being a hole in the ground that lives up to the requirements of the well-plan and includes benchmarks for production, cost and lifespan.

The main pieces of equipment required to drill a hole in the ground is collectively known as a drilling rig. Drilling rigs are classified according to what the rig is supposed to be standing on when it drills and how it is moved around. The main media to stand on is land and water.

It is pretty simple, but that is how it is.

Land rigs are made for working on solid ground where no special requirements are necessary except the area to be flat and of a certain size. All other rigs are made for working either over water or floating in the water. There are barges and jack-up type rigs which are made to stand on the seabed on the bottom of the water and/or swampland and marshes, and there are semi submersibles and drill ships that float in the water. Each type will be described separately on the next pages. It is important to notice that in general, the main drilling equipment on all these rigs are the same. The difference is how it moves and where the drilling location is situated.

There are other sub-types of drilling rigs that are not specifically described here. These rig types include:

• Heli-Rigs, or Helicopter transportable land rigs, these are made mostly of aluminum,

• Dedicated coiled tubing rigs,

• Slanted drilling rigs, used for the Slant hole drilling ,

• HDD, utility drilling rigs, normally hydraulic-driven.,

Most of them use the same type of equipment to drill and most of the processes are very similar with the exception of coiled tubing drilling systems.

In this lecture on drilling equipment, the focus will be put on the drilling rig and its related equipment. The method of drilling the hole is subject for a different lesson.

Some types of equipment are used on all types of rigs, basically the drilling equipment, and other equipment is rig type-specific, i.e., to be able to compensate problems inherent in the rig design or use.

When looking at different drilling rig types and different locations around the world, all drilling rigs consist of the same basic equipment with the same functions, all over the world. A giant concrete platform rig in the North Sea area with 800 people onboard is essentially doing the same as a humble land rig in east Texas. The same types of equipment and people perform just about the same jobs. Of course, the food is more readily available on the big platforms and they have galleys, television rooms and many other recreational facilities to keep the crew occupied while waiting to go back to work.

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