Unmanned and Autonomous Ships

An Overview of MASS

R. Glenn Wright

• Publisher: Routledge
• Year: 2020
• ISBN:
  9780429834349
• Edition: 1
• Topic: Tecnologia e ingegneria
• Subtopic: Trasporti marittimi

Unmanned ships and autonomous ships are quickly becoming a reality, making shipping safer and more efficient. However, traditional tasks and functions are becoming blurred as new technology changes how the unique needs of different sectors are met. In addition to large vessels dedicated to the transport of goods and cargos across the oceans, major efforts are underway towards the automation of small coastal shipping that includes ferries, tugboats, supply and service vessels, and barges. Automated vehicles are also replacing conventional ships for inspecting and servicing pipelines, drilling platforms, wind farms and other offshore installations.

Automated shipping is explored in terms of economics, technology, safety and the environment under the broad themes of ship design and engineering, command and control, navigation, communications, security, regulatory issues, and training. This includes initiatives for autonomous shipping as well as civilian implications of military ship automation programs. This book is primarily for maritime professionals, regulatory authorities, insurers, and environmental groups. It also suits undergraduate students involved in deck officer training, and graduate students and academics involved in research in ship design, operations and management.

Chapter 1

Introduction

This book examines unmanned and autonomous shipping within the context of key design elements and systems necessary to accomplish multiple levels of automation. We begin with this chapter by providing relevant history and cite examples of present-day developments along with some topics of concern voiced by mariners. Subsequent chapters examine the future of maritime shipping and its impact on trade, national economies, technological advancement and the seafarers who have bravely pursued their trades over the centuries. Automation is being accomplished across all levels of shipping from the smallest recreational boats to the largest oil tankers, container ships, cargo carriers and cruise ships. While the contents of this book generally apply to vessels of all sizes and types supporting diverse functions and purposes, its goal is to examine the issues associated with larger surface vessels and their support craft that are operated by professional captains, mates, crews and pilots. No attempt is made to address issues associated with small drones, more commonly referred to as unmanned or autonomous surface vehicles (USVs/ASVs), except as they may be utilized by large vessels, even though there may be great commonality in the technical details of their implementation.

A question exists of whether unmanned and autonomous ships represent the next step in the logical evolution of shipping and ship technology or if they exemplify disruptive innovation that will completely transform the face of maritime shipping as we know it. Although there are vested interests promoting both scenarios, rapid change generally does not occur in the shipping industry and there is no reason to believe that present-day masters and crews are destined for early retirement. Maritime jobs continue to be influenced by changes in technology and economies and few would or even should take the time to argue over the virtues of oar versus sail, steam versus gas turbine, or nuclear versus liquefied natural gas (LNG) or hydrogen fuel cell propulsion. Some of these technologies are relegated to the past while others represent possible alternatives for the future. In the meantime, it is hoped this book can draw attention to the present state of events and activities surrounding the furtherance of what the International Maritime Organization (IMO) refers to as Maritime Autonomous Surface Ships (MASS). Readers may then decide for themselves as to what the future may hold and what influence they have had.

1.1 A Historical Perspective on Advances in Shipping

There are certain events considered key milestones in the development of ships and shipping technology that were hallmarks of change. Sails harnessed the wind to propel ships across vast distances, while oars provided a means of propulsion that made vessels more maneuverable and could be depended upon when the wind was unreliable. Iron ships eventually replaced wooden ships, and steam power replaced sails in general but wind-powered ships using new technologies are still being actively developed. These changes occurred gradually with iron being used initially to connect fasteners and strengthen hulls decades before the appearance of the first iron ships. However, new technology also introduced new problems. One example is how iron ships adversely affected the operation of magnetic compasses. Through the experimentation of astronomer Sir George Biddell Airy in 1839, this problem was solved with his development of correction tables that were subsequently adopted by the Merchant and Royal Navies in England and spread throughout the rest of the world [Airy 1839; Wright 1988]. Such innovations originated from a broad cross-section of people and professions including naval architects as well as inventors, practical tradesmen and scientists, many of whom were not mariners, shipbuilders, or even seafarers. Nevertheless, their discoveries and inventions changed the face of shipping, opened up worldwide trade routes and set the stage for exploration and mass migration on a large scale. Today, similar advances are being made by engineers, metallurgists, chemists, computer scientists and others that may have never set foot on the deck of a ship. Yet, their contributions in the development of new electronic control and guidance systems along with the software through which they operate are essential for today’s ships. The introduction of new technology to aid in vessel communication, navigation and overall situational awareness is summarized by the timeline shown in Figure 1.1. The timeline is not to scale and many of the dates given are approximations as conflicting dates and claims are often present in the literature. However, it provides a good illustration of how developments have accelerated during recent times in four primary disciplines: Construction, propulsion, navigation and communications. The convergence of many aspects of these four disciplines in the modern era has ultimately lead to the present day where the concept of MASS can now be entertained through the establishment of automated command and control over all of the systems needed to operate the vessel and therefore the entire vessel itself.

Figure 1.1 Timeline of new technology introduction on ships.

The following paragraphs provide brief descriptions of new developments in technology and ship function that have taken place relatively independently of each other, yet are essential components to achieve vessel autonomy. The common denominator in modern times among these disciplines is the advent of computer-aided design and simulation of all aspects of ship construction and performance combined with electrical and electronic control of all major ship propulsion, navigation and communications systems.

1.1.1 Construction

Wood floats, and it was a natural progression to build log canoes to large sailing vessels from this material. Towards the late 1700s iron plates began to appear on inland barges, in part out of necessity due to shortages of lumber [Walker 2010]. Ships with hulls made of iron started to appear in 1818, when the iron barge Vulcan was built near Glasgow, Scotland. Overcoming prejudices and concerns among early seafarers as to whether iron ships could actually float was a key inhibitor of early progress [Benson 1923]. Once new processes were developed for manufacturing steel and it became available in sufficient quantities (i.e., tons), large plates of various thicknesses were used to build ships of steel. Improvements in riveting and welding helped to increase vessel size from the 5,000-ton ships of the 1880s to the 250,000-plus-ton ships that are commonplace today. In some cases, attempts have been successful in creating hulls using aluminum. However, difficulties related to welding and galvanic corrosion, especially where a steel shaft passes through the hull, reduce reliability and impose greater maintenance requirements. Carbon fiber composite materials providing lightweight and strong hull forms are presently being developed for smaller vessels but its use for large ships is yet to be realized due to the high costs involved in its production.

Of greatest significance to make possible automated ships are the revolutionary changes in modern era methods and processes used in their construction. As ships have increased in size the former methods of using curves, drawing frames and templates have given way to computer-aided design (CAD), computer-aided engineering (CAE) and computer-aided manufacturing (CAM), making it possible to visualize, evaluate and test design concepts long before the first metal is cut. This includes determining the types of onboard physical and virtual sensors necessary and their proper placement to assess ship performance. The outcome includes better processes that result in improved design and production times at less cost than would otherwise be possible.

1.1.2 Function

Ship designs originated to perform two distinct functions as warships and cargo ships, each with their own unique design features that made them suitable for their task. Cargo ships were also used to transport small numbers of passengers. As the use of sails gave way to steam propulsion, ships of different designs began to be developed for the transportation of inland freight and passengers. Cargo ships continued to develop to support more specialized cargos separating into bulk carriers, tankers and container ships in the 20th century. During this same period passenger ships, with and without cargo, also began to flourish from small river boats and passenger ferries, to great ocean liners and cruise ships designed for pleasure excursions. In the meantime, other specialized ships for fishing, offshore construction and support, drilling, cable laying and a myriad of other uses entered the scene. A broad cross-section of vessels performing these functions is the focus of many autonomy research and development efforts today.

1.1.3 Propulsion

Sails have been present on ships since antiquity and are historically the primary mode of ship propulsion up until modern times. Wind power provided by rotors and other inventions is still being considered for auxiliary ship propulsion. The use of paddles and oars has also complemented sail power. However, the advent of the steam engine heralded the modern age of ship propulsion. Early problems with steam engines and their lack of power were eventually overcome as experience and lessons learned in their use were acquired. However, other problems persisted. Robert Fulton’s steamboat Clermont, otherwise known as Fulton’s Folly, caused spectators to fear when the smoke, flames and steam of the engine made it appear about to explode [Sale 2017]. The 1900s found coal-fired boilers replaced with oil, and today steam has become obsolete and replaced by diesel and turbine power. Nuclear power was used on an experimental basis in the mid-1900s to power commercial ships. However, except for a few specialized ships such as icebreakers, its maritime use is generally relegated to warships. Today on many vessels large engines connected to propellers using drive shafts are being replaced with electric engines connected directly to a propeller enclosed in a steerable gondola or pod suspended below the hull. Liquefied natural gas (LNG) is appearing as a fuel of choice that provides much cleaner performance in terms of environmental emissions. Hydrogen and green ammonia are other potential clean fuel sources being considered for the future.

Just as significant as the types of engines and fuels used on board ships has been the evolution of automated engine and power monitoring and control systems that enable many ships to operate with reduced staffing requirements and unattended machinery spaces. These electronic systems can automatically monitor and control temperatures, pressures, flows, levels, torque and other characteristics of propulsion systems necessary for safe operation.

1.1.4 Navigation

Basic navigation capabilities have been achieved through the invention of the leaded line, nautical chart, compass, chronometer and sextant. The leaded line used to measure water depth was mentioned by Herodotus in the fifth century B.C. [Macaulay 1890]. Early marine charts can be traced back to Marinus of Tyre in the second century [Deetz 1943]. The compass was used for maritime navigation in China around the year 1115 [Ronan 1986]. The chronometer, used for obtaining precise timing information, became available in 1759 [Gould 1921]. The modern sextant had its origins around 1791 [Ifland 1998]. These inventions form the core instruments found in all modern ships. However, the use of electronic systems in the modern era has changed the face of ship navigation.

1.1.5 Communications

The primary method of communication between ships began in the 15th century with the appearance of systems of signal flags and pennants hoisted for communication [Sterling 2011]. These were eventually replaced in the 19th century with the advent of semaphore systems. Light signals were used at night and became more viable with the invention of the electric light bulb. Paralleling advances in navigation, communications by ships with land sites and between ships greatly improved with ...