After a short time away, 1 Minute History is back with an extended Episode. This Episode is on the Bulgarian State Railways (BDZ) Class 46(.01). These were (and still are) the largest tank engines (not just in Europe) but on the planet. Plus the only tank engines to be build with 12 coupled driving wheels on a ridged frame (meaning one frame). This meant the designers had to come up with some creative ways of overcoming the issues of derailing around the tight curves of the mountain passes they would work on. So, if you enjoy this video, please consider liking, commenting and most importantly sharing and subscribing. However, just viewing is most of the time enough to help a channel grow.