Intellectual Property Law for Engineers, Scientists, and Entrepreneurs. Howard B. Rockman

Intellectual Property Law for Engineers, Scientists, and Entrepreneurs - Howard B. Rockman


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instead of running along a regular street, streetcars rolled along special steel rails placed in the middle of the street. On January 17, 1871, a San Francisco citizen, Andrew Smith Hallidie, patented the first cable car, which used metal ropes by which cars were drawn by an endless cable running in a slot between the rails. The cables passed over a steam driven shaft in the power house. The cable systems involved laying expensive infrastructure, and were inefficient to operate because only 18% of a cable car system’s stationary engine power was applied to moving the cars, the remainder of the energy being consumed by moving the weight of the cable.

      The early streetcars also sometimes used mules for motive power. Mules were thought to provide more hours per day of useful transit service than horses, and were especially popular in southern U.S. cities such as New Orleans, Louisiana, as well as in Mexico. By the mid‐1880s, there were 415 street railway companies in the United States, operating over 6,000 miles of track, and carrying 188 million passengers per year using animal‐drawn cars. In the nineteenth century, Mexico also had streetcars in around 1,000 towns, many being animal powered. Although most animal‐drawn lines were closed in the nineteenth century, a few lasted into the twentieth century and later. Toronto’s horse‐drawn streetcar operations, for example, ended in 1891. In New York City, the regular horse‐powered service lasted until 1917, and in Pittsburgh, Pennsylvania, until 1923. The last regular mule‐drawn cars in the United States operated in Sulphur Rock, Arkansas, until 1926.

      Some early streetcars also depended on power supplied by storage batteries; however, these proved to be very expensive and inefficient. Invention of the dynamo or generator led to the application of electric power by means of overhead electrified wires, and to streetcar lines which subsequently proliferated in the United States, Europe, and the rest of the world. Prior to Sprague, there had been early experimental electric railways. Most of these were erected as electrical exhibitions at fairs and expositions as tourist attractions, and were usually dismantled after the exhibitions closed.

      In 1888, Sprague developed streetcars that collected DC electricity from overhead wires, using a spring‐loaded trolley pole that had been invented in 1880. The trolley pole comprised a bent piece called a “bow,” or a collapsible and adjustable frame called a “pantograph,” which was used in foreign countries as compared to the single‐trolley pole in the United States. The ground return was through the iron street rails. Sprague’s trolley pole traveled along the wire above the streetcar. The Sprague system motors were mounted beneath the cars, and centered on the axles, with both motors operated by a single control switch inside the car. Variable speed of the motors was obtained by varying the resistance of the field winding of the motors traversed by the current. Power was supplied through the overhead wire and the trolley pole. Many of these features were also used on subsequent light railways. General Electric and Westinghouse adopted many streetcar features on their railroad equipment.

      After testing his trolley system in 1887 and 1888, Sprague installed the first electric street railway system in Richmond, Virginia. This was the first large‐scale and successful use of electricity to operate an entire system of city streetcars. Overhead wires were installed over the Richmond city streets, and a spring‐loaded streetcar pole would contact the electric wire. Back at the power house, steam engines turned huge generators to produce the electricity required to operate the streetcars. The name “trolley cars” was soon developed for the streetcars powered by electricity. The Richmond electric streetcar system, 12 miles long and with 40 cars, was in operation by February 2, 1888, and had a significant impact upon the burgeoning electric trolley industry in the United States. Sprague’s use of a trolley pole for DC current pick‐up from a single line, with ground return via the street rails, was the pattern that was eventually adopted in many other cities. The hills of Richmond, Virginia, which included grades of over 10%, provided an excellent proving ground for acceptance of Sprague’s new technology. The Richmond electric streetcar system remained in service until November 25, 1949.

      By January 1889, Boston had the first electric streetcars in the United States, which would be the first to operate underground 8 years later. Boston’s last carriage‐drawing horse was retired in 1987. Within a year of the Richmond system, electric power began to replace the more costly horse‐drawn cars in many cities. By 1890, over 200 electric street railways, half incorporating Sprague’s equipment and 90% based on his patents, had begun operation or were planned on several continents. In 1890, the General Electric Company, which manufactured most of Sprague’s equipment, bought Sprague’s electric streetcar business. Sprague left to establish the Sprague Electric Elevator company, and developed and installed electric elevators in several New York buildings before selling that business to Otis Elevator Company.

      The electric streetcar continued to be improved. Tiny, four‐wheeled cars were replaced by heavy, eight‐wheeled cars, providing a much greater carrying capacity. Wooden car bodies were replaced by steel ones. In time, the electric streetcar became the primary means of urban transit.

      Sprague’s later experience with elevator controls led him to develop a multiple unit system of electric railway operation, which accelerated the development of electric streetcar operation. In a multiple unit system, each car of the train carried electric traction motors. Using relays energized by train‐line wires, the engineer or the motorman commanded all of the traction motors in the train to act together. For lighter streetcars, there is no need for a locomotive, so each car in the train can generate revenue. Sprague’s first multiple unit order was from the Southside Elevated Railroad, the first of several elevated railways locally known as the “L” in Chicago. This success was followed by substantial multiple unit contracts in Brooklyn (New York) and Boston (Massachusetts).

      Sprague’s electric traction inventions allowed a significant expansion in the size of cities, while his elevator developments later on permitted greater concentration of workers in commercial sections of urban areas, and increased the profitability of commercial buildings. Over a hundred years later, his inventions also resulted in the development of light rail and rapid transit systems that still function on the same principles today.

      Today, only Toronto still operates a streetcar network essentially unchanged in layout and mode of operation as originally constructed. St. Charles streetcar line in New Orleans is generally viewed as the world’s oldest continuously operating streetcar line.

      Between 1895 and 1929, almost every major American city had at least one streetcar labor strike. Sometimes they lasted only a few days; however, more often, the strikes were marked by almost continuous and sometimes violent conflict. At times, the strikes amounted to prolonged riots and civil insurrection. The 1929 New Orleans streetcar strike was one of the last of its kind. The rise of private automobile ownership took the edge off the impact of the strikes.

      Here is where the history of streetcars gets interesting, at least to me. As the twentieth century moved forward, the heavy expense of track construction and maintenance ultimately rendered streetcars uneconomical. In the United States, streetcars began to be supplanted by automobiles and buses in the 1930s, which trend accelerated during the 1940s and 1950s. Readers who are aged 70 years or older may wonder what happened to all the trolley cars that they rode when they were younger.


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