The locomotives featured in Hutch's post are of opposed piston design. There are reportedly over a 1000 of these made, but is hard to get good data. There are a least 2 versions, the 2TE10U are two unit, and the 3TE10U, are three unit locomotives. There also maybe a single unit version. These can be found in the Ukraine as well as Russia, and maybe in other former Soviet Republics.
http://trainwatchersjournal.blogspot.com/2011/10/3te-in-action-part-1-from-trainsim-ru.html
http://trainwatchersjournal.blogspot.com/search/label/Russian%203TE
http://www.farrail.net/pages/touren-engl/Ukraine-Diesels-2011.php
http://trainspo.com/class/3693/