We should note that Norfolk & Western ordered dual controls on its high hood units. So, the long hood was the designated front of that unit, but it could be operated short hood forward if required, with the Engineer sitting on the "other right" side of the locomotive.
Union Pacific bought long hood forward GP7 and SD7 units in 1953, and then, a year later, reversed its policy and began buying a huge fleet of short (high) hood forward GP9s. They never changed the controls or designated ends of the GP7s and SD7s.
In a head-on collision between an Erie long hood forward GP7 and an Alco-GE PA1, the Engineer and the Fireman aboard the GP7 were killed, whereas the Engineer, the Fireman, and the Road Foreman of Engines aboard the PA1 survived with injuries.
So the long hood was not foolproof protection, although the Erie collision was probably the exception rather than the rule. The big PA1 shoved the entire long hood backward quite a distance. (Neither crew was at fault, by the way. An Operator had failed to flag the GP7 and deliver an order shortening its meeting point with the PA1.)
Really, it was mostly the corporate opinion of the moment that drove the designated front end to be long or short. The long hood was the standard front on Alco-GE RS1, 2, and 3 units, as well as RSD4 and 5 units, but Santa Fe bought a sizable fleet of RSD4s and RSD5s, with the short hood as the front. ATSF had previously bought an Alco-GE demonstrator -- an RS2 1600 hp -- equipped with dual controls, which was built with the long hood as the designated front. Several years later, Santa Fe made the RS2's short hood the designated front. This changed the numbering of the traction motors, as well as the numbers and sides of the axle bearings and other appliances.
