Back in the late 1940s and into the 1950s Electro-Motive Division of GM – the pioneer in diesel-electric locomotives – built two different versions on the same platform. They built the streamlined F7 and E8/E9 locomotives and the GP7 locomotives built for easy servicing.
Check the links for pix.
Chicago Milwaukee St Paul & Pacific EMD F7 Diesels
The EMD GP7 Series
EMD E8 - Wikipedia, the free encyclopedia
EMD E9 - Wikipedia, the free encyclopedia
The F7 (freight) and E8/E9 (passenger) locomotives were called “covered wagons.” They were a bear to work on because of the bodywork. The GP series locomotives were very easy to work on. You could open a single dorr and change a power assembly (on EMD engines you replace entire cylinder assemblies – liner, head, conn rod and the valve gear – all in a single unit. You sent a bad power assembly off to the back shop for repair and tossed a replacement power assembly into the locomotive and got it back out on the road making money).
In twenty years of model competition the sleek E and F models were found to have no measureable aerodynamic advantage over the boxy GP units, and the ease of maintenance made the GP style win out. Today, something that looks a lot like a GP7 dominates US railroads.
File:CSX209inNNVA.jpg - Wikipedia, the free encyclopedia
Interestingly, this last pic (a GE AC4400CW) was taken at the CSX Huntington Locomotive Shop, where I worked back in the day.
The short nose evolved over the years almost back into a shape kinda like the F7. After the GP7 and GP9 which had full-height short ends, most locomotives grew a lower short end for better crew visibility. GP18s, GP20s, GP24s, GP30s, GP35s, GP38/39/40/40-2 and GP50 locomotives retained the walkways on the short nose like the GP7 had but starting with GP60s they “filled in” the walkway and put a nose door to allow access to the front. The “filled in” nose allowed bigger sand hoppers on the short end. The GE competitors followed suit with EMD on exterior sheet metal. Those bodes are not sheet metal but rather 7 gauge plate.
If you look down on a train from altitude they resemble a spear moving along the ground. A train in the US is commonly a mile and a half long, so the frontal area doesn’t affect the train much, considering that train weighs over 10,000 short tons.
Probably the easiest thing the US could do to reduce oil usage would be to find a way to electrify freight railroad mainlines. There are only about 10,000 miles of mainline left, but they haul a staggering amount of freight over those mainlines. Electrification would allow the US to use plentiful coal or nuclear power to move stuff.