All four photos were excellent and I would have been proud to be listed as the photographer of any one of them. I chose number 4 the Iowa Interstate because of the dramatic lighting. IMHO it was/is a real attention grabber.
Yes, am also strongly partial to locale, which is actually on MRL’s 4th subdivision bridge #50 (M/p 50.75±) crossing Beaver Creek, some 3¼ miles SE of Trout Creek, Montana. It’s on the former BN’s ex-NP main, relocated by the latter (*c.*1957 for the Noxon Rapids dam) from the previous alignment under the Clark Fork River in background. It was the scene of NP’s last Z-8 4-6-6-4 to run, #5140 was used-as a “ballast tamper” a year more-than half a century before Tom’s shot, and that structure w/the trio of 118 ft. spans’ a U.S.Army-Corps of Engineers’ design.
I tend to agree with another poster that while all four show GEVOs, none speak strongly to that theme. So this time I voted strictly by the picture I like best, in this case Tom’s.
I’d guess Tom Danneman’s shot is the best of the group. I hope he zoomed in and took a shot of the locomotives alone as well, since that would have shown up the technical differences.
Tom’s comment about the GEVO having a larger radiator is not technically correct.
The GEVO radiator is about the same size as that on an AC4400 or a Dash 9, thus the same as the other locomotives in the photo. The GEVO, however, has a quite separate air to air intercooler just forward of the radiator, with its own fans above it and its own intake below it. It is just that the two casings are the same width and height and next to eachother and appear to be one unit.
The intercooler takes the air from the turbocharger and cools it before it enters the engine, increasing its density. In the GEVO this is done by cooling it in a heat exchanger where air is drawn across the pipes containing the engine air by two high speed fans in the casing above. The intakes can be recognised by their different angle to the radiator intakes behind them.
The radiator itself is in the usual place for a GE with a big single fan below it which is the way GEs have been since the U25 (with a couple of twin fan exceptions, the C39-8 and AC6000 and maybe a couple of others).
The intercooler does help to cool the engine, but it isn’t part of the radiator, and since it doesn’t contain a liquid coolant, doesn’t count as a radiator in normal terms. You could perhaps use the term “cooling group” as has been used in Europe.
The Dash 9 and AC4400 had intercoolers, but these used water to cool the air, and were much more compact. These in turn used the radiator to cool the water, increasing the load on the radiator. So using the air to air intercooler in the GEVO reduces the load on the radiator, which is about the same size as earlier units, and helps to acheive Tier II emissions standards.