The history of the development of the railway track
Originally appeared on track roads developments of stone, in the mines and coal mines. The first mention of them belong to the middle of the XVI century. The so-called rails were wooden bars - Ledge. According to this way of rutting horse could carry the load is 4 times greater than for ordinary dirt road. However, the wooden sleepers quickly wore out carts went astray. To reduce wear wooden sleepers, they were strengthened with iron or iron bars. To prevent gatherings carts out of the way to make steel sleepers chimes.
Cast iron rails appeared in the XVIII century. One of the first iron road length of about 160 m was built on the Alexander factory in Petrozavodsk (Onega plant) in 1788 under the direction of A. Yartseva. Track width was about 0.8 m, the rail - angled. On this road was 12 times easier than on ordinary dirt roads.
In the operation of railways rail surface to become clogged and have a greater rolling resistance. This reason, apparently, led to the emergence of convex rails with an elliptical shape of the rolling surface, imposed a mining engineer PK Frolov. Wheels were chute corresponding to the shape of the rail head. This was the prototype of the modern rail railway rail. With the advent of steam engines increased sharply wheel loads and speeds (already at the first locomotives) reached 50 km / h or more. Given the high dynamic loads from the wheels of the rolling stock and the need to work in bending in all embodiments of the rails to some extent on the profile approaches the shape of an I-beam. Widely used two constructions rails - a two-headed and shirokopodoshvenny. RelsovPri design creating a two-headed rail, the authors believe that after one wear rail head can be turned and use the other side. However, this idea was not justified, since the wear of the upper head from the impact of the wheels of the rolling stock was accompanied by a deterioration of the bottom. First rails are generally made of cast iron. It was found that the steel rail wear less and more evenly than cast iron. Currently, worldwide use, only steel rails, which metal (except carbon) contains silicon, manganese, and other additives that enhance its quality. Widespread heat hardened rails, hardness of the material of which increased from 290-300 to 360-380 Brinell, which is 2-3 times increases their durability.
P.K. Frolovym on Zmeinogorsk mine Kolyvano Resurrection plants in the Altai was built the world's first railway, with all its main elements: the road had embankments, cuttings, viaduct, bridge over the river Korbalihu 20 stone pillars up to 11 meters. The slope of the line does not exceed 14%. Along this road one horse could carry cargo to 25 times greater than on a dirt road.
In 1837 the railway was built Petersburg - Tsarskoye Selo (Pushkin), 27 km. Almost all of the roadbed was located on the mound. On the road was built 42 small wooden bridge spans 2 - 3 m. The bridge through the channel length was 25.6 m. The rails were two-headed, strengthened with wedges in cast iron pillows, which were attached to the sleepers 3 m long pegs. The length of the rails was different - from 3.7 to 6.9 m. The ballast consisted of a layer of gravel and crushed stone layer with a total thickness of 45-50 cm. The largest slope on the road was 2%. Track width was originally 6 feet (1829 mm).
A big step forward in the development of the railways, including the railway line, was the construction in 1842-1851 years. line Petersburg - Moscow length of 651 km. On the first line are applied shirokopodoshvennye rails manufactured at the factory Lyudinovo weighing 29 kg (linear density of 29 kg / m), a length of 5,486 m and a height of 89 mm; ballast layer had a thickness of 0.5 m on the mound and in the recesses of 0.8 m and consisted of two layers: the top - of crushed granite thickness of 18 cm and bottom - sand or gravel. Under construction contractors began to apply only sand ballast. Track width at the insistence of PP Melnikov and other Russian engineers was installed 5 feet (1524 mm). Melnikov stressed that the ruling in favor of overseas track width of 1435 mm "no compelling reasons" track in 1829 mm lead to useless waste of materials, and load-carrying capacity of wagons will not increase.
Along with the development of railway construction and developed the science of the railway line. Engineer PP Melnikov in 1835 proposed a formula for the calculation of the rails with the influence of the moving load. The impact of rolling stock on the path have been investigated by Professor KY Tseglinskim in 1903 in his work "Track in curves." Great contribution to the calculations of the strength of the way was made by Academician NP Petrov. Russian experts did much to improve the science of railway track, but in tsarist Russia, many of their undertakings did not find sufficient support. Therefore, rail transport in Tsarist Russia was technically underdeveloped.
In 1913, the length of the rail network was 71.7 thousand. Km. They were placed very unevenly. The main part of the network (83%) are in the European part of the country. On the road lay the rails light weight type (1 m) 30 kg, impregnated sleepers, ballast sand. It was decided to strengthen the track structure, including the start introducing ballast ballast. In the period before World War II was built a number of important railway lines, including the Turkestan-Siberian Railway (1452 km). Railway cargo turnover in 1940 exceeded the 1913 level by 5.4 times.
The progressive development of railway transport was interrupted in 1941 during the Great Patriotic War by rail with the necessary technical equipment and qualified personnel, successfully provide the basic needs for transportation, as the front and rear. During the war and in the post-war period of the first Five-Year Plan were to do more work to restore rail. Was restored 85 th. Km of main routes, a large number of bridges, stations, lines and other structures.
In the postwar years, along with the construction of new railway lines much work is done to enhance the way. Began to be rolled at domestic plants and placed in the way of heavy rail types (P65), introduced reinforced concrete sleepers, jointless way.
The length of railways of the USSR was about 12% of the length of railway lines in the world. They performed more than half of all turnover of railways, and within the country to carry more than 70% of cargo.
Congested railways of the USSR had no equal in the world. The average traffic density of more than 5 times the traffic density roads United States, about 6 times - Germany and France, 15 times - England. Every year on the development of material and technical base of rail transport in the USSR allocated 4.5 billion rubles.
To ensure the increase train speeds and increased axle loads rolling Strengthen and improve the design of the permanent way. On the major highways of the country fit jointless path rails type R65 and R75 on concrete sleepers; on congested lines used hardened and alloyed rails; in some areas the railway track was laid on concrete slabs or reinforced concrete block foundation; improved intermediate bonding.
In the late 80-ies in the USSR operational length of the railway network was about 145 thousand. Km. In the railway network includes 32 road, 185 branches railways, over 11,000 railway stations.
Rail profile over the past 140 years has changed little, but his weight has increased from 20 - 24 to 75 - 77 kg / m. Road to the broad gauge most commonly used rails weighing 54 - 60 kg / m in Western Europe, 65 - 75 kg / m in the CIS, 66 - 70 kg / m in the United States, Canada, Australia. On high-speed lines used throughout the rails is not easier 60 kg / m. However, in Europe and the USA, as well as in other countries in the low-density and station tracks, there are still light rails weighing 33 - 44 kg / m. These rails are widely used on the narrow gauge roads. Various embodiments of a compound of the rails to the sleepers with crutches or screws existed since the construction of the first railways. New in the last 50 - 60 years is the bonding to the intermediate transfer type spring providing an elastic connection to the base of the rail flange. Wooden sleepers little changed their form over the last 140 years. However, most of the first railway sleepers stacked impregnated wood which broke down after 8 - 12 years. It should be noted that even during the construction of St. Petersburg - Moscow railway sleepers impregnated under pressure. Currently, all the roads of the world in the way laid wooden sleepers impregnated with antiseptic, which increases the service life of at least 2 times.
Reinforced concrete sleepers are widely used in Europe and Asia, mainly since 1950 Lifetime concrete sleepers is 50 - 60 years. In the CIS countries jointless only way laid on concrete sleepers with elastic rubber pads, shock absorbers in the under-rail sections.
To enhance the rail base increasingly are experimenting with the use of frame, block and monolithic reinforced concrete structures. One of the typical designs on bridges, overpasses and tunnels is of plate rail base.
Sand, gravel, crushed stone, as well as 140 years ago, are typical components of the ballast. It should be noted that even on the road St. Petersburg - Moscow staged a two-layer sand prism, the bulk of which is covered with a layer of gravel thickness up to 18 cm. A qualitatively new solution, which is still at the stage of operational tests is a monolithic bond ballast latex and other cementitious compositions that is 2 - 4 times may increase the carrying capacity rail base.