| Great shot! Very strange though this F7, maybe on old F3?^ has F9 style intakes and the old fans, quite a mix of parts on this lead motor. 
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| Without looking into it, that could be a late production F3. A few late F3's got the stainless steel far grills right before an F7's were produced. 
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| Regardless - it's a beautiful train! Thanks for posting Roger. 
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| Thanks so much for showing us this photo, love the old ATSF shots. 
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| On ATSF I believe 17 & 18 were The Super Chief.  19 & 20 were The Chief.  The Chief normally carried a number of head end baggage and mail cars.| Posted by mmi16 on October 12, 2018 |  | 
 
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| #21 started life as part of the original Santa Fe order of six F3 diesel sets, #16LABC thru #21LABC SETS.  The first six unit sets did not have stainless sides and were painted silver (or was it aluminum?) as can be seen with a glance at the trailing units in the picture.  These had the two rectangular, screened-over Dynamic Brake vents and the high cooling fan shrouds.  They also were delivered without the stainless steel grills, instead with the original chicken wire over the openings; and with three portholes in the "A" units' sides.  Standardization throughout their lives caused several more mods to make all of the 3 thru 7s to be essentially be "F7s".| Posted by Al Wood on October 12, 2018 |  | 
 
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| Al Wood, thanks for the notes there.  I noticed several odd things on the first unit,  keep in mind I wasn't born yet but I pay attention to this stuff,  the F3 style dynamics are still on the second unit versus obviously a replaced hatch with a 36" fan on the first instead of the latter preferred 48" 
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