There are number of variables like current, wire dia, number of turns, dia and length of electromagnet. The distance at which force is applied is constant
The distance is nearly 12 inches. Power is nearly 88.4 KW. The electromagnet should be not more than a few meters at max. Weight is not much of an issue. Calculation is not needed just need an idea on how to select the optimum values of variables. The formula I am using is F=(mu)(n*I)^2/2g^2 mu= permeability
The project is about use of regenerative braking to charge electomagnets to attract the rails. This force is being utilised to avoid derailment during train emergency braking. Just a college project in analysis not any research.