Train in movie "Dr. Zhivago"

[James Sofonia]

I recently rented this movie wanting to watch the train scenes again. I seem to remember a very long shot of the train traveling at speed down heavy snow covered tracks. It was shot out the cab and almost shocking to travel so fast on rails you couldn't even see if they were still there. Too bad I couldn't find that scene. It may have been cut from the original theater release, or I'm thinking of some other film from the mid 1960's. Anyone, anyone?

EDIT:
Here is a portion of the plot mentioning the train escape in Dr. Zhivago.

After the war, Yuri returns to his wife Tonya, son Sasha, and Alexander. Yevgraf informs him his poems have been condemned by Soviet censors as antagonistic to Communism. Yevgraf arranges for passes and documents in order for Yuri and his family to escape from the new political capital of Moscow to the far away Gromeko estate at Varykino, in the Ural Mountains. Zhivago, Tonya, Sasha and Alexander now board a heavily guarded cattle train, at which time they are informed that they will be traveling through contested territory, which is being secured by the infamous Bolshevik commander named Strelnikov.

Some of the winter sequences, mostly landscape scenes and Yuri's escape from the Partisans, were filmed in Finland. Winter scenes of the family travelling to Yuriatin by rail were filmed in Canada. All the trains used in the film were Spanish trains like RENFE 240 ex 1400 MZA and Strelnikov's armoured train towed by the Renfe 2–8–2 class Mikado.