Paul Barber (@yellow10)
It has been a few days since I have checked in on this one... And boy have you made some great progress. The rust on the exhaust looks very realistic too.
As a former tanker, I'll try to answer your questions about the track being on or off the tank...
Back when these tanks were built, the steel track pins that were used to hold the track blocks together had a limited lifespan. The quality of the metal wasn't nearly as good as what we have today. On average, these tanks could get between 200 to 300 miles out of a set of tracks and more often than not, the track pins would start breaking well before this time ran out.
So they would remove the tracks, drive the tanks as close to the battlefield as they could, then re install the tracks.
By doing this, they discovered several things. First off, like Gary stated, the wear on the roads was much better, and it did tear up the asphalt or concrete pavement if it was present on the roads they travelled if the tracks were installed.
Secondly, they found out the top highway speeds were also much higher. This allowed them to travel longer distances and also go much faster on the road wheels, than when the tracks were installed. The tracks were heavy and it took horsepower and torque to move them. By operating the tanks without the tracks of roads, (and even good solid unpaved ground), the engine was not nearly as taxed, so the top speed was increased.
It also saved the tracks for when they were really needed. Granted it was a lot of work to do, but it was probably worthwhile in the long run, provided they had time to reinstall them when needed.
I'm guessing here on the T-34 having power to the road wheels like this tank did. I'm basing it off something my Dad told me about one of his combat experiences in Korea. Dad told me on his death bed, that he had shot the tracks off one side of a T-34. He also said it kept moving towards him afterwards... I don't know what weapon system he used to do this, be it a bazooka or possibly a main gun round from a Sherman or a Pershing / Patton tank. He clammed up immediately afterwards and changed the subject. Sadly I never got the rest of the story.
I don't know if the T-34 dad fired at was still driving in a somewhat curved line towards him, using the other good track or not. So I really don't know for certain if the T-34/85 had power to the road wheels or not.
But I have read that the early T-34's may have had a similar setup to what the BT tanks did. The jury is still out on this one.
Happy Easter !