Reviewed by: Electric Railways, 1880–1990 William D. Middleton (bio) Electric Railways, 1880–1990. By Michael C. Duffy. London: Institution of Electrical Engineers, 2003. Pp. xxi+452. $84. In reviewing the development of electric railways from their inception, Michael Duffy has taken on an ambitious topic. While he emphasizes developments in Great Britain, he provides full coverage of work in the United States and in Europe in order to complete the story of what has been very much an international engineering endeavor. Going further than previous works on electric railways, Duffy describes the developments in centralized power-generating plants and distribution that proved crucial to the success of electric traction. Equally important is his account of the development of the signaling, communications, and control required for the operation of high-density electrification. An early chapter covers the period that brought electric railways to the beginning of commercial practicality, which Duffy attributes largely to American inventors. Another describes the work of Frank J. Sprague and others in developing street railway systems and then interurban electric railways and heavy-duty electric rapid transit, notably the extensive London subway system, which in large part followed American practice. While low-voltage direct current (DC) systems were adopted for the early electric railways, there were many doubts about the suitability of this technology for general electrification. During the 1890s the Alsatian electrical inventor J. J. Heilmann conducted studies on a variety of electrical systems and developed the "Fusée E´lectrique," or Electric Rocket, a self-contained DC locomotive carrying its own steam power plant. Early British electrification largely went to low-voltage DC systems developed for urban and suburban networks, with the Southern Railway and its predecessors growing into one of the largest of all such systems. Most of the early electrification projects in the United States, such as the New York Central's and the Pennsylvania Railroad's at New York, used low-voltage DC as well, but North American suppliers soon recognized the potentially superior properties of alternating current, completing notable AC electrifications as early as 1907 on the New York, New Haven and Hartford. Later development of electric railways largely used AC or high-voltage DC. [End Page 211] In Europe, systems involving both three-phase and single-phase in a variety of voltages and frequencies were tried, with extensive three-phase electrification being installed in Switzerland and Italy. The only three-phase electrification in North America was the Great Northern's first Cascade Tunnel in 1909. The Norfolk and Western, and later the Virginian, used a single-phase power distribution and locomotives equipped with phase-splitting devices to provide three-phase induction motors that were superior to single-phase commutator or DC series motors for heavy-haul coal service. High-voltage DC electrifications, ranging from 1,200 to 3,000 volts, were widely adopted in North America, while almost all AC electrification used an 11,000-volt, 25-hertz system employing commutator motors; a few lines used motor-generator locomotives to provide low-voltage DC to the traction motors. The preponderance of European practice from the 1920s followed similar single-phase AC and high-voltage DC. Duffy devotes particular attention to the development of electric power generation and distribution. Early electrifications that used low-voltage DC generation were too inefficient except in rapid transit or other installations that Duffy calls "enforced electrification." The advantages of centralized power stations using high-voltage AC power supply and distribution were recognized early, and this system was helped by the development of high-capacity rotary converters installed in on-line substations to convert the supply to DC. But the problems of high power drops and the requirement for frequent substations rendered the large-scale use of low-voltage DC infeasible for heavy-duty electric railways. Although the development of efficient high-voltage DC and AC systems greatly expanded the potential range of electrification, many early lines required their own generating plants, and even when industrial power supplies became available they required expensive conversions to the railway systems. The expansion of industrial-frequency systems and the use of mercury-arc rectifiers in fixed installations from the 1920s on improved the efficiency of power supply. The...
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