America is much more known for widespread use of diesel locomotives than Europe, but they had a handful of interesting designs of juicers. For a Eurofag like me these look very, very weird. Let's take the Little Joe for example - has 6 traction motors mounted on powered axles which are located in a rigid frame, with pilot trucks on both ends. For comparison - a typical European freight locomotive of that time had two 3-axle bogies with traction motors on them, placed underneath the locomotive's body.

On top of that, US passenger electrics had steam generators for heating well up to mid-seventies while HEP facilities were industry standard in European locomotives (even some freight ones) right after WW2.

Would some US train nerd explain this to me, please?