The question is whether freight could be hauled along train tracks using only beasts of burden as a power source. My first ideas of a design involved tying, say, horses, to a belt which would drive a shaft, and, through simple gearing, provide power to push the train forward. The first few pieces of information that I have are that a horse can be expected to express, naturally, one horsepower over reasonable amounts of time, and that a single railcar weighs 30 tons. Initially, I was looking into the breaking the static friction of steel-on-steel, but the whole point of wheeled systems is that you don't have to do that. It became clear that the significant numbers, which I have no idea how to obtain, are the component pieces of the overall friction of a freight car, predominantly, I would think, the friction of the greased axles. The deformation of the wheel and track would also sap some power, as would the friction in the gear train set up to power it. I am skirting the edge of my understanding of kinematics and friction, and am squarely out of my depth in engineering. Also, this is my first post in this forum, so if I have in some way violated a rule, I apologize in advance. Otherwise, I thank you all for your consideration and input.