Exchange of wheels of train to adjust to different rail gauges in Russia and China

Mongolia has 2,810 kilometres (1,750 mi) of railway tracks of 1,520 mm (4 ft 11+27⁄32 in) Russian gauge. China has 159,000 kilometers (98,798 mi) of train tracks laid out using the 1,435 mm (4 ft 8+½ in) railway gauge which is standard across North America, Europe, Japan and Australia. International trains across Mongolia - China border, therefore, go through railway engineering magic to adjust to the change in track gauge size.

The wheels of Trans-Mongolian Express international trains crossing the Mongolia - China border have to be replaced at the border for the trains to continue across the two countries connected by the offshoot of the Trans-Siberian Railway track that originates southbound at Irkutsk, Russia. The Trans-Siberian Express track continues east from Irkutsk to Vladivostok, Russia.

The exchange of wheels below train carriages and wagons is called "Bogie Exchange". This is achieved at a railway yard in Erengot (二连浩特;), China just south of the border with Mongolia, and just before the Erlian, China train station (二连站). The last station in Mongolia before the border is Zamiin-Uud Station (Замын-Үүд).

The signage on the rail yard says "The Wheel Change Warehouse at Jining Depot of Hohhot Railway Bureau (换轮库呼铁局集宁车辆段)" in Erenhot.

In the context of rail cars, a "Bogie" is a wheeled chassis that supports and guides the car along the tracks. It typically consists of two or more axles with wheels attached to them.

The changing of train wheels for the correct gauge for the destination country across the border is carried out by (a) disassembling trains to their component carriages and wagons (b) positioning each carriage and wagon carefully next to hydraulic lifts (c) lifting up each carriage and wagon with the bogie left behind down on the rail track (d) removing each bogie away from the bottom on the track while the carriages and wagons are suspended in air by the hydraulic lifts (e) rolling in the correct gauge bogies below the carriages and wagons (f) using the hydraulic jacks to drop the train cars and wagons back on the correct bogie.

The entire process takes around four hours per train and is a marvel to watch. Passengers have the option of staying back in their carriages or getting off and walking around the secure facility of the railway yard.

Erlian train station, Erenhot, China

While talking about epic Trans-Siberian and Trans-Mongolian Railway journeys, also keep in mind the Trans-Manchurian Railway, a crucial link in the Trans-Siberian network, which is another railway route that traverses the historical region of Manchuria, now primarily within northeastern China. The Trans-Manchurian Railway branches off the Trans-Siberian line near Lake Baikal, heading southeast through Russia and China. This railway, historically significant, played a pivotal role in connecting Russia to the Pacific coast and facilitating trade and economic development in the region. Its strategic importance was underscored by its involvement in geopolitical struggles, notably during the Russo-Japanese War and the Second World War. Today, the Trans-Manchurian Railway remains a vital transportation corridor, linking Russia and China, and offering a unique travel experience for those seeking to explore the vast landscapes and rich cultural heritage of the region.

Our photo-stories continue from Russia, Mongolia and China.