Changing bogies to Russian coaches at the border of Mongolia and China at the city of Erenhot (also known as Erlian).
Picture reproduced from 4rail.net with explicit permission of the copyright holder. Picture by Juha Ojaluoma 2009.

Old bogies waiting to be assembled under the coaches.
Picture reproduced from 4rail.net with explicit permission of the copyright holder. Picture from Erenhot by Juha Ojaluoma 2009.

Crude oil train in the Gobi desert.
Picture reproduced from 4rail.net with explicit permission of the copyright holder. Picture by Juha Ojaluoma 2009.

From the desert right into a mountain. This is the Moscow - Ulanbaatar (Ulan Bator) express train.
Picture reproduced from 4rail.net with explicit permission of the copyright holder. Picture by Juha Ojaluoma 2009.

Russian RZD's express train from Moscow to Ulaanbaatar (Ulan Bator) led by a Russian 2M62 double locomotive somewhere in the highlands of Mongolia.
Picture reproduced from 4rail.net with explicit permission of the copyright holder. Picture by Juha Ojaluoma 2009.

Another Russian express train bound for Moscow, headed by a class 2M62 double diesel locomotive, is crossing the desert of Gobi.
Picture taken from the train's window 11.7.2011 by Markku Salo.