Not Your Usual Nose... Santa Fe 5058-5070 were perhaps the most interesting of the road's 187 SD40-2s. These units, built in April and May 1979, were equipped with Oscitrol signal lights in their noses. The Oscitrol light was designed with no moving parts, providing an advantage over mechanical Mars Lights and Gyralights. Oscitrol lights featured three lights arranged vertically: The two uppermost lamps were clear (white), while the lower was a red Undesired Emergency Light (UDE) light. The two white lights were aimed to the right and left of the projected centerline of the unit by 3 degrees, and had a flash rate of 50 right-left flashes per minute, replicating the mechanical warning lights. (These lights "flashed" by going from dim to bright.) The red UDE light was aimed straight ahead and would flash upon an emergency braking condition (low air pressure), also at 50 flashes per minute. Oddly, I never saw any of these Santa Fe units with the Oscitrol lights activated!
