How a train take turns though there is no differential gear?
They don’t slip.The tread on a wheel is cone shaped and the rails are canted in towards each other.This forces the wheel sets to ride centered on the rail.When a train goes around a curve the wheels are forced to one side or the other.When that happens the wheels act like a differential because of the cone shape.One side is riding on the smaller diameter of the wheel and the other side the larger diameter.As the wheels come back onto straight rail the wheels center themselves again so that both sides are turning at the same speed.If you’ve ever heard a train going slowly around a curve the squealing noise you hear is the wheels doing what i just described.On curves is also the only time the flanges on a wheel actually contact the rail(unless a truck is “hunting”).That is why oilers are placed on curves.The flanges contacting the rail is also the reason the curves need the rail replaced more often than tangent track.
