Why would the wheel rims rotate at twice the speed of the train? If the train advanced along the track 1m, surely the part of the wheel in contact with the track must also have moved 1m?
The middle a the wheel moves at the same speed as the vehicle relative to the ground. (X + 0)
The top of the wheel moves at twice the speed of the vechile relative to the ground. (X + X)
Put another way, the top of the wheel must go faster than the vehicle or it does not rotate.
It's an odd diagram to draw out, as that result is pretty counter-intuitive.