When crossing the border between Europe and Russia, trains always change wheels or transfer passengers to another train. The reason for this is the different track gauges, the dimensions of which were established many years ago.
Stephenson's track
In many European countries, in China and the USA, the size of the railroad track is 4 feet and 8.5 inches, that is, 1435 mm. This width was adopted by engineer George Stephenson to build the first passenger rail line from Liverpool to Manchester. At that time, such a width of the paths was the narrowest of all.
It was not by chance that Stephenson stopped at a width of 1435 mm - it corresponded to the distance between the wheels of Roman chariots, and later of stagecoaches. Well, the first English steam locomotive, as you know, was built exactly along the width of the stagecoach.
A little later, according to the project of engineer Brinell, a railway with a width of 2135 mm was built. It was believed that such a distance would create conditions for increasing the speed of the locomotive. Throughout Europe, a real leapfrog began, associated with ruts of different widths, and steam locomotives began to run irregularly. As a result, in 1846, the British Parliament issued a decree obliging all railway owners to alter the gauges to the size of Stephenson.
Russian gauge
In Russia, the railway track is exactly 85 cm wider than Stephenson's and is 1520 mm. True, they did not stop at this size right away. The very first Russian railway St. Petersburg - Tsarskoe Selo, which opened in 1837, generally had a track width of 1829 mm.
In 1843, the engineer Melnikov designed the St. Petersburg - Moscow railway and laid a 1524 mm track in it. In his opinion, this size was much more optimal for the speed and stability of the rolling stock than Stephenson. In addition, it provided a more convenient placement of the locomotive mechanism and an increase in the volume of the boiler and the mass of the cargo. A railway track of this size was subsequently spread not only throughout Russia, but also in Finland and Mongolia.
There is also a version that the dimensions of the railway track, different from the European ones, were connected with the purpose of making it difficult for the enemy to enter troops in Russia in the event of an attack on the country.
In the Soviet years, the track gauge was reduced by 4 mm, and all railways were transferred to the 1520 mm track gauge, which remains to this day, including in the countries of the former CIS. This was due to the goal of increasing the speed of movement of railroad trains without carrying out their modernization, as well as to increase the stability in the operation of freight trains. In Finland, the track gauge remained the same - 1524 mm, and in Russia, some metro lines and trams still have such a gauge.
