 The GE E60CP and E60CH electric locomotives were having derailment problems as well; the GE P30CH had the same truck design as E60s and rode poorly, although it did not exhibit the same tendency to derail.Amtrak decided to abandon the SDP40F in favor of the F40PH, a four-axle design with none of the riding problems of the six-axle locomotives.Amtrak traded 40 SDP40Fs back to EMD; components including the prime mover were installed into an F40PH's frame.