Det största problemet har vad jag vet varit att ledskenorna gradvis äts upp av överslaget som sker när strömmen går från den ena skenan, genom projektilen (kallad armature i texten nedan) och sen över till den andra skenan. Här är en saxad förklaring:
(...)the current flows up on rail, through the armature which travels perpendicular to the rails, and down the other rail. The result is a magnetic field between the two rails (B = 2x(u0/2pi)x(I/r)) and an intercepting field by the armature. The rails repel one another (F = u0I1I2L/2piR) and they both repel the armature (F = ILB). Since rails are both fixed the net result is a propulsive force on the armature, which will be accelerated forward by electromagnetic means (A=ILB/M). This differs from conventional mass accelerators in that no gases are used, and it differs from conventional electromagnetic accelerators in that the field trails behind the projectile at all times; since no coils are used coupling occurs at a much greater degree and efficiency values would tend to be higher. The potential velocities achievable can also be much higher.
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