Union Pacific 500-Series F9 Locomotives

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Were Union Pacific's 500-series locomotives called F9, or were they F9m? The 'm' suffix denotes a modified locomotive, and these were not modified F9 units, nor were they upgraded F3 units.

Much to the chagrin of many in the railfan publishing community, Union Pacific's 500 class units were not rebuilt F3s; they were F9s in a variety of F3 carbodies.

Union Pacific and the builder, EMD, always referred to these units as F9s, because that's what they were. True, they were built using major portions of the carbodies of various configurations of trade-in F3 locomotives, but all internal electrical and mechanical components were new. To save money on the overall contract, the builder did reuse the truck frames, and reconditioned and re-qualified cores of some of the trade-in traction motors and radiator fans. Research in original documents shows that these 500 series locomotives were considered by both UP and by EMD only to be new F9 locomotives.


Union Pacific operated a total of 89 F3 cab units and 90 F3 cabless booster units, numbered in the 1400, 1500 and 1550 series road numbers. In addition, the road operated a total fleet of 20 F7 cab units, 36 F7 cabless booster units, and two FP7 cab units, all in the higher-numbered 1400 series. The low-numbered 1500-series F3s were actually units renumbered from the 1400 series, and along with the 1550 series F3 units, were all assigned to UP's Oregon Short Line subsidiary in western Wyoming, northern Utah, southern Idaho, and eastern Oregon.

In 1958 and 1959, UP sent all of the remaining 1500-horsepower 1500 and 1550 series units to EMD at La Grange, Illinois, to have them upgraded to 1750-horsepower units. They returned in 1958 and 1959 as 500-series F9s. And there's the rub. There seems to be some good-natured disagreement among locomotive and UP historians as to exactly what to call these units.

The features of the upgraded locomotives included new 567C diesel engines, D12 main generators with D14 accessory alternators, and D37 traction motors, all of which were features of EMD's F9 locomotive.

Union Pacific Sources

In its locomotive folio diagrams, UP called them F9s.

The September 1, 1968 issue of UP's computer printout listing of locomotives showed the 500 series as F9. This designation remained the same in the May 1, 1969, January 1, 1971, June 1, 1971, August 1, 1971, September 1, 1971, October 1, 1971, and December 1, 1971 editions. They were not shown in the April 1, 1972 edition.

In a listing of units that were proposed to be retired, dated April 12, 1970, UP referred to the 500 series units as "F9-A" and "F9-B".

A letter dated March 6, 1972 from D. S. Neuhart, UP's Chief Mechanical Officer, described the February 25, 1972 "sale of 19 EMD F9A and 12 EMD F9B used diesel electric freight locomotives, Series 503A-539A and 509B-542B to the Chicago, Rock Island and Pacific Railroad Company." The letter also listed the dates of delivery for each of the units to the Rock Island at either Council Bluffs or Kansas City.

EMD Sources

EMD's 1970 Locomotive Reference data book, on page U11, called the units F9s, the full description being, "F9  16  567C  1750HP".

Although EMD used the GP7M and GP9M model designation for other railroads' locomotives in the 1971 edition of their Locomotive Reference book, they did not use the similar F9M for the Union Pacific locomotives. The F9M model is not included in the 1971 edition of the book, but on page U2, EMD again used the F9 designation to describe these Union Pacific locomotives. Although the units were retired in 1972, they were shown again in the 1973 edition, on page 92, as F9s, with notations that most had been sold to CRI&P.

Railfan Sources

A photo caption in the January 1960 issue of Trains magazine on pages 6 and 7, shows the units as F9s.

In Kratville's "Motive Power of the Union Pacific" published in 1960 (Barnhart Press), the 500 series were called "F-9". From page 228: "Forty F-3 units in the 1500 series have been upgraded to F-9's and renumbered in the 500 series." The roster in the back also refers to the units as F-9s.

In the original UP roster in Extra 2200 South, printed in three parts in November and December 1962, and January 1963, the 500 series units were shown on page 9 of Part II in the January 1963 issue as: "EMD Model F-9 1750HP 16-567C eng, db, 62:15. Reblt from 1500, 1550 series".

No mention is made of these upgraded units in the Diesel Spotter's Guide (1967) or in the Second Diesel Spotter's Guide (1973).

In the February 1968 issue of Extra 2200 South, page 9, a news item from John Brunner reported that trade in units for the then-new SD45s would include "500 series EMD F9's rebuilt from F3's".

In a strange designation, in the June 1968 issue of Extra 2200 South, page 9, David B. Williams reported on the assignments of the 500 series units: "F3-7-9's #507..."

In the occasional news item in Extra 2200 South, the 500 series were referred to as F9s in various issues from Issue 1, January 1968, to Issue 35, November-December 1971.

Issue 36 of Extra 2200 South, September-October 1972, had a photo caption for units sold to Rock Island, on page 16. The caption showed F9m as the locomotive model.

In Issue 41, Extra 2200 South, July-August 1973, page 11, Extra 2200 South shows the Rock Island units: "Recent 9-unit power lashup on Train 20 included six ex UP F9's (3 A's, 3 B's) and a parent-road F7A."

But on the same page, another report says: "RI -- (9/73) Ex UP F3's common power out of Fort Worth."

In Hol Wagner's "Union Pacific Motive Power Review 1968-1977" (Motive Power Services, 1978), on page 95, the models "F9-Am" and "F9-Bm" were used.

I used F9Am and F9Bm in September 1978 in my original typewritten manuscript for the UP roster that appeared in five issues of Extra 2200 South in 1979 and 1980. This was based largely on my original handwritten version from 1973-1974, compiled on the large foldout sheets from Don Dover. This handwritten version used the F9A and F9B models. However, in my original note 26 for that same typewritten roster, I used F9A and F9B.

The 500 series was shown in Part II of the UP roster in Extra 2200 South, Issue 68, April-May-June 1979, page 20. The model shown was F3Au(F9) and F3Bu(F9). In the photo caption on page 21, the model is shown as F3A/Bu's (F9A/Bm's).

Note 22 on page 20 reads: "F3Au's (F9Am's): UP selected 41 1500-series F3A's in 1958 to be sent back to EMD/LaGrange for thorough upgrading to F9 standards (16-567C engines at 1750hp, etc.), external modifications were limited to 48" dynamic brake fan and fifth louver set ahead of the front porthole." Note 23 reads: "F3Bu's (F9Bm's): same general information as in Note 22 except B-unit."

No mention of the 500 series units in any of George Cockle's columns in Pacific News or Pacific RailNews, from his first column in June 1976 through to his last column in June 1983.

No mention of the 500 series units in any of George Cockle's books.

They Were F9s, Not F3s

These units were shown in numerous Union Pacific and EMD documents as F9s. It was the railfans who stuck them with the silly F3u or F9u, or F9m label. All of the internal features made them F9s. About a quarter of their external features also made them F9s. As mentioned above, they were F9s that happen to have been remanufactured using a variety of F3 carbodies.

In the three times I have been through the various documents at Union Pacific in Omaha, I have never seen the F9s in UP's 500 class referred to as anything but F9s. All of the EMD documentation also calls them F9s. To most people looking at the photos, it soon becomes apparent that at least some of them were F3s, and some were F7s. In fact, all were rebuilt from F3s in the 1500 (renumbered from 1400 class F3s), and the 1550 class (delivered new in Phase IV F3s that looked like F7s).

In a move different from what SP did, as pointed out above by Joe Strapac, UP recapitalized these units, and took them into their account books as new F9s. The cost of these *new* F9s was reduced to UP by using trade-in F3s, and EMD using the F3 carbodies for the F9s. The one specification letter that I saw said that the only components reused were the carbody, the trucks, and as many of the radiator fans as possible. The units had new engines, new generators, new traction motors, and new wiring and cabling.

When I was at UP working in the Salt Lake City shops, there were full sets of EMD parts catalogs, with marvelous listings in the F unit carbody components section that listed each railroad, and the unique carbody panels each road needed for its own units. In the UP section, there was listings for the road's 1400 class F3s and F7s, and for their 500 class F9s, specifically calling them F9s. I talked the shop superintendent into letting me have these now-obsolete parts listings. Unfortunately, I no longer have these books.

Much to the chagrin of many in the railfan publishing community, Union Pacific's 500 class units were not rebuilt F3s; they were F9s in a variety of F3 carbodies. I know it's a small line in a gray area, and a lot of people disagree, so the challenge has always been to come up with some sort of compromise model designation. I have always disliked the silly U suffix (it just doesn't look right), but the R and M suffixes were really too general to work well. The same thing applies to today's UP 4700 class SD40-2s, in SD45 carbodies (the SD39s were a lot more obscure). Call them what you want, but whatever you or I call them, we will have to explain why. There is no railfan standard because too many egos are involved. And the railroads and builders (rebuilders) themselves don't help, for the same reason, whatever designation they use depends on who in the organization is writing the specification, or the manual or the model listing.