The rails can have a length of even 80 meters; in this case their manufacture and transport presents greater difficulties. Their thickness, and consequently their weight, vary according to the use to which they are destined; generally they have a weight from 30 to 75 kilograms per meter. An important rule in the installation of rails is to leave between them a separation of some centimeters, because the variations of temperature cause expansion and contraction in the rails. To connect them are used elements such as bondbars, clamps and bolts. Obviously, the separation between rails is what creates the characteristic noise that one perceives when traveling on the train; hence, the length of the rails determines the frequency of the noise.
Tunnel built in the mountains of Colorado.
Two rails, installed side to side, form the railway or railroad. The railway is not very difficult to install; however, there are some aspects that must not be lost sight of; in curves, for example, apart from placing shorter rails and raising the rails of the outer side it is required to use the softest curvature possible to reduce to the minimum the centrifugal force, which otherwise could put the trains in severe risk of derailment. Regarding the width of the railway - known as gauge -, a convention between the European countries set in 1884 a tolerance term from 1.435 to 1.445 meters and adopted this as the standard railway width. To this convention did not adhere Russia, Spain and Ireland, which adopted greater or lesser widths. A reduced width is less costly, both regarding installation and service, allowing also curves of lesser width, easier for mountainous terrain.
One of the first types of pneumatic drill.
To finish with these paragraphs, just a mention of the smallest railway in which the frame is made of a single body. This system is called Decauville, as its builder, and its rails, of about five meters in length, are fixed to metallic sleepers. The intention was to produce prefabricated sections of light and narrow railway, portable and easy to disassemble and transport. The gauge of the railway was initially 40 centimeters, but later increased to 50-60 centimeters.
The railway on the mountain
In the middle of the 19th century the Austro-Hungarian Empire was crossed by efficient railway lines linking Vienna with other cities, but all of these lines were built in plains, because, like in the other countries, the problem posed by steep slopes had not been still addressed. Emperor Franz Joseph I, due to military requirements, needed a faster link with the territories under his command, and because of this he projected a direct communication between Vienna and Carinthia. A project from the engineer of Venetian origin Karl von Ghega was well received by the Emperor; the railway would have to cross the Semmering, a mountainous region with an altitude of 980 meters, with very daring viaducts in a route of 41 kilometers in length.
The picturesque line connecting Villach, Lubiana, Graz and Vienna was finished in 1854 and happily inaugurated by the Emperor himself. It had 15 short tunnels and the train overcame a grade of 500 meters, with slopes of 25 per 1000. For this line it was necessary to research locomotives capable of dragging the convoys along notable slopes, and for such a contest was started. This one was won by the company Mattei, and the locomotive was baptized as "Bavaria". Once achieved that the trains climbed to the mountains, it was proposed to cross them directly to save kilometers and overcome difficulties that otherwise would be insoluble. So were started to be perforated the most important massifs with audacious construction works which are worthy of admiration.
The railways with the highest altitudes in the world were built not in Europe but in South America. These are some important ones, ordered from higher to lower elevation (in meters): the Bolivian (4880); Lima-Orova, in Peru (4834); Arequipa-Puno, in Peru (4770); Arica-La Paz, in Chile (4264); Durán-Quito, in Ecuador (4100); Mendoza-Santiago, in Argentina (3489); Jungfrau, in the Bernese Alps (3457); Denver-Río Grande, in Colorado (3453); Djibuti-Addis Abbeba, in Ethiopia (2606); Darjeeling, in the Himalaya (2170); and the Albula-Bernina, in Switzerland (1823).
And finally, some of the longest railway tunnels (in meters) are: Huntington Lake, in California (21760); the Simplon, in Switzerland-Italy (19728); Lotschberg, in Switzerland (14606); Otira, in New Zealand (8450); the Trans-Andean, in Argentina-Chile (8100); Hoosac, in Massachussetts (7640); and Sutro, in Nevada (6000).Continue reading...