Today I will post pictures on my P5a's. The first P5s were built as box cabs. The crews didn't like the box cab design for safety reasons. A grade crossing accident in which the crew were killed led to the substitution of a streamlined steeple type cab for the final 28 locomotives. This design was not given a separate class designation since it was mechanically and electrically identical; they were called class P5a (modified), and colloquially Modifieds. The P5a Modified design was taken from the drawing board of the GG1 which was being designed at the time.
