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An Encyclopedia of the History of Technology part 62

An Encyclopedia of the History of Technology part 62. This one of a kind encyclopedia presents the entire field of technology from rudimentary agricultural tools to communication satellites in this first of its kind reference source. Following an introduction that discusses basic tools, devices, and mechanisms, the chapters are grouped into five parts that provide detailed information on materials, power and engineering, transportation, communication and calculation, and technology and society, revealing how different technologies have together evolved to produce enormous changes in the course of history | PART THREE TRANSPORT Figure 11.3 First electrification in Australia was a section of Victoria Railways 5ft 3in gauge Melbourne suburban lines electrified at 1500 volts DC in 1919. Australian Information Service. suburban lines of British main line companies in the London and Liverpool areas. The first section of the Paris Metro had been opened in 1900 the first New York subway line in 1904. The Metropolitan and District underground railways in London had been electrified between 1901 and 1905 and several more deep level tube railways had been made beneath London. Signalling When the District Railway was electrified it was equipped with automatic signalling of a type already in use in the USA track circuits actuated electropneumatically operated signals. Those in the open were semaphores in the tunnels coloured spectacle glasses moved in front of gas lamps. The Metropolitan then used a similar system but lit the tunnel signals electrically. From these the modern colour light signal evolved. In 1905 the District Railway became the first to install an illuminated track diagram in a signal box. In 1906 the Great Western Railway started to install automatic train control using a system in which a ramp between the rails made contact with a shoe beneath the locomotive to apply brakes when it approached a signal at danger. Ancillary buildings Railway buildings at this period passenger and goods stations signal boxes locomotive and carriage sheds engineering works and administrative offices 592 RAIL ranged in enormous quantity from the minuscule to the magnificent and reflected the architectural tastes and techniques of their time. Civil engineering works such as the Forth Bridge or the Victoria Falls bridge across the Zambesi River ranked among the greatest then built and likewise reflected available methods and materials. Reinforced concrete was coming into use for railway structures and also as a replacement for wood as sleeper material. THE AFTERMATH OF WAR The First .