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An Encyclopedia of the History of Technology part 63

An Encyclopedia of the History of Technology part 63. 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 Australia. Its 386km 240 mile route was built during 1964-72 to carry iron ore from mine to port and over it ore is carried in mile-long trains of up to 210 wagons. Average net trainload during 1982-3 was about 17 650 tonnes. The heaviest regular train-load in Britain is small by comparison but still no mean figure 3350 tonnes of limestone carried in 43 wagons. Bulk freight operations such as these exemplify the continuing and indeed increasing use of railways in developed countries for specialized functions. Another of these is rapid transit swift passenger transport within large cities and conurbations. The term embraces traditional underground and tube railways the upgraded tramway systems of certain cities mostly on the Continent which rather than abandon trams when street congestion made them untenable put the city-centre sections underground and recently-built systems combining the best features of both including reserved-track surface operation where possible. Of these systems there are many for the principle is as attractive in western countries such as the USA to reduce traffic jams caused by excessive numbers of private cars as it is in Communist countries for moving large numbers of carless people. In Britain the Tyne Wear Metro of which the first section was opened in 1980 uses two-car train sets based on continental tramcar design operated over routes which are partly newly constructed and much of that in new tunnels beneath central Newcastle upon Tyne and partly over former British Rail routes. Rapid transit lends itself to automated control of trains to a greater or lesser degree. As long ago as 1927 the Post Office brought into use its own tube railway to carry mails beneath London with automatic operation. The track circuits instead of operating signals disconnect current from the section to the rear of each train. This railway however carries no passengers. On the Victoria Line built between 1962 and 1971 and when opened the .