This first film has the most railway action. It was filmed on the Baikal Amur Mainline, or BAM. A lot of the railway towns on this line have fallen on hard times after the collapse of the Soviet Union. After translating some of the comments with Google Translate, it may be that the events in this film was based on an actual event. Diesels seen in the film are the 2TE type (mainline,) and the TEM2 type seen in the yards.
The next film also features a mishap, but is a lot more concentrated on the railway bureaucracy. The electric locomotives are the VL80 type.
This last film follows a cast of characters on an ill fated passenger train.