Steam train

[Fred Brackin]

Originally Posted by Prince Charon

Sticking tractor (tank, in modern times) treads on an armoured train should be feasible,

Well, physically possible anyway but painfully inefficient.

Using the Ve2 formulas for the same power vehicles with railway wheels at TL6 get 3.2 x the speed as vehicles with treads.

Then you're going to need big treads because railway vehicles are designed without concern for off-road speed or ground pressure. At a guess you'd need treads not only for the whole length of the engine and cars but as wide as the bult-up roadbed that supports the tracks.

By then you're probably hitting recursive issues with the weight of the treads affecting performance. At 70 tons for a modern boxcar you're already slightly over the weight of a modern MBT and you're using engines with much lower power-to-weight ratios than any used in historical tanks. A TL5 triple expansion steam engine needs a base 50lbs per KW or output and even a TL6 steam turbine needs 25. AWWII tank engine only needs 6 lbs for diesel and 3 lbs for gasoline..The gas turbine that powers the modern Abrams might be as low as 1 lb per KW of output.

I'm also not in love with the idea of unpowered treads on the cars with only the engine's treads being powered.

It probably is physically possible though.