EMD FP7 - F7B Standard DC -- Southern Pacific(TM) 6454, 8297 (gray, red, white)Details: Providing enough steam to power train heat and some air conditioning systems on postwar trains taxed the standard water supply of EMD F units set up for passenger service, prompting EMD to rollout the new FP7 in 1949. Though outwardly similar, FP7s were actually four feet longer to accommodate bigger water tanks with a capacity of 950 US gallons. Standard passenger power into the Amtrak era and beyond (with some also handling freight chores),