 Former countries of the USSR, as well as Mongolia, use a track gauge of 1,520 mm (4 ft 11 27 ⁄ 32 in). The international standard rail gauge used in most of Europe and China is 1,435 mm (4 ft 8 1 ⁄ 2 in). As a result, trains cannot run from China or European countries into or out of the former USSR without changing bogies. Large facilities to carry out this procedure exist at most border crossing between the "Russian" and "standard" gauge territories (e.g., at Zabaykalsk or Erenhot) Changing the bogies on a rail car takes hours and special, heavy equipment. In many cases (especially, containerized freight), freight is transshipped from one train to another instead of changing the bogies. As of 2016, this is what's usually done with China-Europe container trains at places such as Khorgos; it is reported that containers can be moved from one train to another in as little as 47 minutes. In the case of liquids, frozen goods and hazardous materials, however, the bogies are usually changed.
