CK-12 Engineering: An Introduction for High School

by Dale Baker

  The first rail locomotive was built in 1803 in England by Richard Trevithick (1771–1833). The first railroad in England, however, did not go into service until 1825. In 1829, Robert Stevenson (1803–1859) designed a locomotive called the “Rocket,” which had many of the features of later steam locomotives; these include a multitubular boiler and wheels driven by near-horizontal pistons. Figure 17 shows a drawing of the Rocket.

  Figure 6.17

  Drawing of the locomotive Rocket.

  The first commercial railroad in the United States was the Baltimore and Ohio Company; in 1830, it opened the first 13 miles of track in the United States. By 1860, there was over 30,000 miles of track in the United States. American engineers adapted British locomotive designs to the unique constraints and problems posed by the United States. American engines were larger and more powerful than British engines because American rail systems had steeper grades; American tracks also had tighter curves, necessitating the design of the bogie truck. American train tracks are not fenced, so engineers designed cow catchers on the front of the locomotive. New engineering techniques were also developed for the construction of the rail lines and the bridges and tunnels that they required.

  One of the greater engineering feats of the industrial revolution was building the First Transcontinental Railroad. This railroad linked Omaha, Nebraska, with Sacramento, California. It was authorized by the United States federal government in 1862 and was completed in 1869. This railroad dramatically changed travel to the western United States; before its completion, this travel involved a journey of many months in a horse- or oxen-drawn wagon. After its completion, the journey could be made in a week.

  Rise of the Corporation

  The pace of technology development increased steadily in the last half of the nineteenth century and the first decades of the twentieth century. New technologies were involved in the creation and growth of corporations; fortunes were made through new technological developments.

  A great change for engineering was that science began to directly inform engineering in fields such as steelmaking, generation and distribution of electricity, and chemistry. Standards for engineering education, which increasingly involved a university education, were developed, and the modern engineering disciplines of Electrical and Chemical Engineering joined Civil and Mechanical Engineering. This was coupled with the creation of engineering professional societies.

  Electricity

  By 1870, scientists such as Michael Faraday (1791–1867) and James Maxwell (1831–1879) had provided a firm theoretical understanding of electricity. Electricity was widely used in communications—the telegraph made long-distance communication essentially instantaneous. Electricity was supplied to the telegraph by a battery or an inefficient generator, which was still very expensive.

  A dynamo is a machine that converts rotational energy supplied by a steam engine or waterwheel into electrical energy. During the 1870s, dynamos were developed that provided efficient methods of generating electricity. This set the stage for the development and widespread use of the lightbulb.

  Thomas Edison (1847–1931) is generally given credit for the invention of the lightbulb in 1878. He was a prolific inventor, developing devices such as the phonograph (shown in Figure 18), which recorded and played back sound, and a moving picture projector; he is quoted as saying “genius is one percent inspiration and ninety nine percent perspiration.” He was not a solitary inventor—he led a large research laboratory with over 30 scientists, engineers, and craftsmen. His practice of using an organized research laboratory to develop new inventions was soon adopted by many others and formed the basis of much industrial manufacturing.

  Figure 6.18

  Thomas Edison and an early phonograph.

  Edison began the development of the lightbulb to provide a method of lighting homes and businesses at night. His goal was to make money. The competing technologies of the time were gas lighting and carbon arc electric lamps. Carbon arc lamps emit a very bright, harsh light; they were not suitable for indoor lighting. Thus, one goal of Edison's development was creation of a light source that provided lower light levels than carbon arc lamps. To be economically competitive, electric lighting had to be safer and cheaper than gas lights; this imposed difficult constraints on the design of the lightbulb.

  As is often the case, Edison did not invent the lightbulb from scratch. Rather, he adapted and improved existing technologies, particularly related to the lightbulb filament and to creating a vacuum within the lightbulb, to create a working bulb. In addition to the lightbulb, his research lab created a system of dynamos and wiring to provide electricity to power his bulbs in homes and businesses. In the process, they developed many devices that are still used in modern systems, including fuses to prevent current overloads, meters to measure electricity use, and switches to turn lights off and on. Edison’s first lighting system was installed in New York City in 1881. Figure 19 shows one of Edison’s original lightbulbs.

  Figure 6.19

  An original bulb made by Edisons workshop in 1879.

  Although he was hailed as the inventor of the lightbulb, Edison’s electrical system was not the technology that was ultimately used to produce and distribute electricity in most parts of the world. Edison’s system used direct current (DC). Shortly after Edison installed his first system, George Westinghouse (1846–1914) developed a competing system that used alternating current (AC). The first AC current system was installed in 1886, and several more followed in the next several years. The competition between Westinghouse and Edison to dominate the electrical generation and distributional business was labeled “The War of the Currents.” AC systems had significant technical advantages over DC systems, but Edison mounted an aggressive public relations campaign that played on the public’s fears of electrocution. In one particularly distressing case, the state of New York bought an electric chair to execute criminals; this chair operated using AC current. Edison attempted to name the process of being executed “being Westinghoused.” By 1892, AC became the primary method of electrical distribution, and even Edison’s company began manufacturing AC equipment.

  The Edison General Electric Company merged with the the Thomson-Houston Electric Company to create General Electric (GE) in 1892. This company still exist today and is a leader in many technology fields including electrical generation and distribution, aircraft engines, medical systems, and media production and distribution.

  Powered Flight

  Orville Wright (1871–1948) and Wilbur Wright (1867–1912) were brothers who are credited with having achieved the first powered flight. They built on the earlier work of many pioneering engineers, including Otto Lilienthal (1848–1896) and Samuel Langley (1834–1906). They owned and operated a printing press and a bicycle shop in Dayton, Ohio. The bicycle shop provided both funding and mechanical experience for their investigation into powered flight.

  They began serious investigation into flight in 1899. The death of Otto Lilienthal in a glider accident in 1896 as well as other accidents involving experimental gliders convinced them that an extremely important aspect of developing a heavier than air flying machine is understanding how to control it. They felt that the other primary issues—sufficiently powerful engines and shaping the wings for lift—had been solved. Thus, unlike other investigators of flight, they conducted careful experiments with kites and gliders to understand how to create controllable airplane designs. They developed a technique of wing warping (bending of wings) to cause the aircraft to bank and move up and down.

  In 1900, the Wright brothers began experiments at Kitty Hawk, North Carolina, with gliders. Between 1900 and 1903, they combined scientific theory with careful experiments to refine the equation that predicted the lift of wings. In the process, they discovered that long, narrow wings provided more lift than short, wide ones. They used this discovery in creating their powered aircraft. They also discovered how to control an aircraft in turns—by banking the wings and turning the nose with a ver
tical rudder. In 1902, they made between 700 and 1,000 flights in gliders to confirm that they could be properly controlled. They applied for a patent on their three axis method of control in 1903.

  In the 1890s, the nascent automobile industry had developed the gasoline internal combustion engine to the point that, by mid-1903, it was a viable power source for the Wrights planned airplane. Their shop mechanic built an engine in six weeks. They took their airplane to Kitty Hawk, North Carolina. After several weeks of delays necessitated by repairs of propeller shafts, on December 17, 1903, the Wright brothers made four powered flights, the longest of which was over 850 feet. Figure 20 shows this first powered flight.

  Figure 6.20

  The Wright brothers first powered flight.

  Between 1903 and 1908, they developed the Wright flyer, which they attempted to market to the U.S. Army. Between 1908 and 1910, they gave demonstration flights in France and the United States. They were celebrities in France, and thousands of people gathered to watch their airplanes fly. They incorporated the Wright company in 1909; Orville Wright sold the company in 1915.

  Neither of the Wright brothers had a formal education in engineering or science. They did have significant technical experience from their bicycle shop, and they used the scientific method to develop the control structures that made their airplane successful.

  Automated Typesetting

  The late nineteenth and early twentieth century saw the automation of the setting of type, much as the early nineteenth century saw the automation of the printing process. Engineers invented machines that could cast and set type much faster than could be done by hand. The two most successful of these machines were the Monotype and Linotype machines.

  Tolbert Lanston (1844–1914) invented the Monotype casting system. This system, developed between 1885 and 1896, cast the individual letters from molten type metal, and then arranged the letters into rows of type. This system consisted of two parts: a keyboard, at which an operator would select the sequence of letters and other symbols that were then punched into a paper tape, and the typecaster, which took the paper tape and cast the appropriate letter blocks. Figure 21 shows a Monotype keyboard with the paper tape punch. The Lanston Monotype Machine Company was founded in 1887 and eventually manufactured machines in both the United States and England. In 1907, the US Government Printing Office was the largest installation of Monotype machines in the world, with 162 keyboards and 124 casters.

  Figure 6.21

  A keyboard for the Monotype casting system.

  Ottmar Mergenthaler (1854–1899) invented the Linotype machine. The first Linotype machine was installed in the New York Tribune newspaper office in July of 1886. The Mergenthaler Linotype Company was founded in Brooklyn, New York, in 1889. Figure 22 shows a Linotype machine. Using input from an operator at a keyboard, the machine assembled matrices for an entire line of text, which was then cast in type metal as a slug.

  Figure 6.22

  A Linotype type-casting system.

  The Monotype and Linotype machines were the primary methods of setting type until the 1950s. In the 1950s, metal type began to be replaced by photo typesetting, in which photographic processes are used to create plates with raised areas that are inked before coming in contact with the paper.

  Engineering as a Modern Profession

  Through the middle of the nineteenth century, most engineers received training through apprenticeships and on the job experience. In the latter third of the nineteenth century, land-grant colleges were established, and many of these included engineering schools. These schools provided programs of study in the established fields of Civil and Mechanical Engineering as well as the newer fields of Chemical and Electrical engineering. Even though many of the great engineering accomplishments at the turn of the century were made by craftsmen without a formal engineering education, the newly established corporate research laboratories increasingly began hiring workers with university degrees in engineering.

  In the latter half of the nineteenth century, engineers began to form trade organizations with the purpose of increasing the stature of the engineering profession. These organizations develop standards to distinguish professional engineers with necessary qualifications from technicians and others without qualifications. The first of these trade organizations was the American Society of Civil Engineers, founded in 1852. The American Institute of Mining and Metallurgical Engineers was founded in 1871, the American Society of Mechanical Engineers was founded in 1880, and the American Institute of Electrical Engineers was founded in 1884. These organizations often had close links with colleges and universities, and helped define the theory and practical aspects of an engineering education.

  The Early Twentieth Century

  In the early twentieth century, engineering accomplishments increasingly began to affect the lives of middle-class Americans. The automobile provided increased mobility to millions. The development of commercial radio broadcast began the creation of a popular culture and an American mass identity.

  Henry Ford and Mass Production

  Henry Ford (1863–1947) left home at 16 to work as an apprentice machinist in Detroit, Michigan. He was later hired by the Westinghouse Company to service steam engines, and in 1893 became the chief engineer of the Edison Illumination Company. This position provided time and money for him to begin experimenting with vehicles powered by gasoline internal combustion engines. Before 1903, he created several companies to produce and market gasoline powered automobiles, but they were not economically successful.

  In 1903, Henry Ford created the Ford Motor Company. His goal was to produce an affordable and reliable car that could be purchased by an average American farmer or worker. After several years of experimentation and design, the Ford Company company introduced the Model T in 1908; Figure 23 shows a Model T. In many aspects, the Model T was quite similar to the car of today: it had a steering wheel on the left, its engine was enclosed in a hood, and it had a windshield and rear wheel drive. Note that Henry Ford did not personally develop the detailed design of the model T. This was done by a team of engineers with the range of skills and expertise necessary for the project.

  Figure 6.23

  A restored Ford Model T.

  One of the technical advances that made the Model T possible was the use of a vanadium steel alloy with much higher strength than normal steel. However, from an engineering point of view, the most significant innovation associated with the Model T was the production system that allowed it to be produced and sold very economically. Between 1909 and 1913, the Ford company adopted all of the techniques necessary for mass production using an assembly line. These techniques include

  Use of standardized parts.

  Specialized labor—each worker performed a very specific operation in the assembly of a Model T.

  Moving assembly line—partially assembled vehicles were moved automatically down the line, past stations where workers added components.

  Figure 24 shows the use of an assembly line to attach car bodies to the car frame. These assembly-line techniques dramatically reduced the cost of assembling the Model T, and the sales price of the car was repeatedly lowered. In 1909, its first full year of production, 18,000 vehicles were built; in 1915, one-half million were sold, and in 1920, the production exceeded one million annually.

  Figure 6.24

  Part of a Ford assembly line.

  To retain workers in the difficult assembly-line environment, Ford paid his workers five dollars per day, which is a very high wage for that time period. This, combined with the low price of the Model T, meant that Ford workers could actually afford to buy the car on which they worked. Such buying power and affordability was unprecedented. By the end of the 1920s, one in five people owned an automobile, which dramatically affected the structure of American society.

  Radio

  The advent of radio, which provided live broadcast to millions of listeners simultaneously, was a significant factor in the creation of an American nat
ional identity.

  In the last several decades of the nineteenth century, physicists such as James Maxwell (1831–1879) and Heinrich Hertz (1857–1894) developed a theoretical understanding of the propagation of electromagnetic waves. They also experimented with methods of producing electromagnetic waves. This work was primarily for scientific purposes; they did not anticipate practical applications of their work.

  Beginning in 1894, Guglielmo Marconi (1874–1937), an Italian inventor, began experimenting with radio transmitters and receivers with the goal of creating a system of “wireless telegraphy”—a system that could transmit information much as the telegraph did, but without the need for wires to connect transmitter and receiver. Similar to many engineers before him, he adapted and combined existing technology to form a system that could be used to communicate between land and ships. The system allowed the transmission of Morse code, similar to a wire-based telegraph. By 1903, he had successfully demonstrated the transmission of signals across the Atlantic Ocean. On the basis of his technology, he founded the Marconi Wireless Telegraph Company in 1900. Many of his patents in wireless technology were challenged by Nikola Tesla (1856–1943) and others in the United States and other countries; decisions in these cases vary from case to case and from jurisdiction to jurisdiction.