Hello, Steve!
Thank you for your a greeting on Russian

!
As far as I know, first a railroad of Russia was build to 6 foot gauge. Later, was build to 5 foot (1524 mm). It was chose by the technical and economic assessment. In 1970 it was confirm on 1520 mm.
The VL80 (ru: ВЛ80) is prominent a AC electric dual-section locomotive for cargo trains.
These enjoys the accolade of having the longest production span of any Soviet electric locomotive. All variants of the series were built at the Novocherkassk Electric Locomotive Plant (NEVZ).
The first VL80-s were characterizing by their mercury arc rectifiers. Later, they were replaced with silicon ones, thus giving birth to the VL80k (ru: ВЛ80к) series. The "к" stands for "кремний", the Russian word for silicon. It been produced in 1963 - 1971. The first VL80k-s were headlight round of a buffer-beam, they is still do working on the Ukrainian Railways.