External and Internal Features Added To UP Locomotives
By Don Strack
(This is a work in progress; research continues.)
This page was last updated on February 4, 2012.
Radios
Radios were first used on Union Pacific diesel yard switchers, as early as 1940. (research continues...)
Automatic Cab Signals
In 1949, Union Pacific first added Automatic Cab Signals as part of a general improvement of traffic control along the railroad's Oregon-Washington Railroad & Navigation Co., mainline between The Dalles and East Portland, via Graham (85.3 miles). The system was used in conjunction with Automatic Block Signals to improve the flow and control of traffic by installing duplicating signal indicators inside the locomotive cabs, with an acknowledging action required from the engineer upon receiving an more restrictive signal indication. The greatest advantage of the ACS system was that it allowed trains to operate at maximum speed in inclement weather, without concern of visibility of trackside signals. The line was called the Oregon Fourth Subdivision.
UP has ACS on the Portland Sub between Crates, the west end of double track at The Dalles, through to Troutdale. The previous edition of the timetable also showed ACS on the Graham line from Troutdale to East Portland but the current edition doesn't show it, just CTC. (Bill Maltby, March 2000)
At about the same time in 1949, ACS was installed along the Nebraska and Wyoming mainlines, west into Ogden, Utah.
A note on terminology:
- ACS denotes Automatic Cab Signals, and is the trackside equipment, which explains why it is noted in employee timetables.
- CCS denotes Coded Cab Signals (full name: Code Cab Signals-Safety Control, CCS-SC) and is the equipment located on the locomotives themselves
As of March 2000, UP had ACS in the following locations (from Mark Amfahr):
- Summit (Omaha, Neb.) to Riverdale CPC 988 (near Ogden, Utah)
- Laramie to Green River completed before September 1951
- Cheyenne to Laramie, and Green River to Ogden added by April 1961
- Menoken, Kansas (near Topeka) to Gibbon, Neb.
- O'Fallons, Neb. (just west of North Platte) to near South Morrill, Neb.
- The Dalles, Ore., to East Portland, via the Graham line, added in about 1949.
Automatic Train Stop
On September 17, 2009, Olin Dirks wrote:
UP E units were equipped with Coded Cab Signals (CCS) for the Overland Route main line. The pickup bar was located under the pilots. The ATSF between Daggett and Riverside was equipped with a different system, Automatic Train Stop (ATS), in order to comply with FRA requirements to exceed 79 mph running between Victorville and Barstow. Some UP E8's and E9's appear to have a Santa Fe style ATS pickup shoe on the right side of their 5th axle.
According to an internal company roster dated September 1, 1968, all of UP's E9s (UP 900-914, 943-961) and all of their E8s (UP 925-942) were equipped with ATS.
I don't have anything from earlier times, but it is likely that only certain units had ATS, and by the late 1960s, all potential lead units had been modified.
Multiple Unit Connections
During the early years of dieselization, multiple unit control was achieved by the use of twin receptacles, one with 12 pins and the other with 21 pins. On later units with dynamic braking, the necessary field loop connector mounted atop the left side MU boxes. From the mid 1960s on, UP converted the left side twin receptacles to a single 27 pin connector, putting a blank plate over the extra location. After the conversion, the twin receptacles (21/12-pin) were painted red, and the single receptacle (27-pin) was painted blue.
The 21/12 configuration was initially used by American Locomotive Co. Locomotives with 12/21 M.U. connections also used either 6DS or 6RL air brake schedules, which also meant that they needed matching air hose connections.
When the later 27-pin connections became available, sometimes known as AAR 27-pin, the air brake schedule was updated to 24RL.
Rich Sievers wrote on Trainorders.com on February 20, 2004:
Using the photo as a guide, on the engineer's side from the top down are the Field Loop plug, the 12-pin m.u. plug, and the 21-pin m.u. plug. On the fireman's side from the top down are the Field Loop plug and the 27-pin plug (with its cover painted blue).
UP ordered the 12-pin/21-pin arrangement in addition to the standard 27-pin plug until late 1966, so the last "straight" SD40, 3082, should've been the last new unit to have it. Thereafter, UP used just the standard 27-pin plug, and many unit that still had the 12-pin/21-pin plugs had those removed.
Field Loop refers to a type of dynamic braking control that was common at the time. Today, virtually all dynamic brake control functions are trainlined through the regular 27-pin m.u. cable.
Beginning in the mid to late 1960s, there was an on-going mod that was removing the 21-12 plugs (the red ones) and blanking off the openings. At the same time, the DB field loop plug was being deactivated, with the 27 pin plug taking over the function (this required a mod to the DB control circuits). On the Geeps, there had been an earlier program to convert one of the left side plugs from 21-12 to 27 pins. This was done to match the GP30s and GP35s/DD35s. (Don Strack, posted to Trainorders.com on February 20, 2004)
UP E8/9 Snow Shields
Why did UP put snowshields on top of their E8s and E9s?
The original question was asked by Tom Cockle on the Diesel Modeler's email group in July 1999: "UP was well known for applying snow shields over the winterization hatches on its E8s and E9s. However, they were applied over the blank end of said hatch, not over the grill end, and I am wondering just what they were supposed to do. Can anyone explain how they worked? I have applied these shields (Utah Pacific Part # 83) to my UP P2K E8A and kitbashed E8B, but am wondering about their intended function."
Warren Johnson, a 30-year veteran mechanic who retired from UP's Salt Lake diesel shop, remembers being told that the snow shields on UP's E units were in fact "put on top of the locomotive to disturb the air at the top of the locomotive. The reason they wanted to do this was to break up the exhaust coming out of the top of the locomotive. Who would want to ride in a domeliner and see nothing but exhaust? It worked the same as the smokelifters on the steam engines used in passenger service. The original pieces had angle iron welded to the top as a stiffener as well as something to disturb the air flow across the top."
In July 1999, Steve Orth asked Bill Metzger for his comments about whether or not there is a hole under the snow shield. Bill answered on July 21, 1999:
"Yes, there were holes cut in all winterization hatches. This was to improve airflow in the thin air of Wyoming. Short of turbos, this was the best way to get more air into the carbody (remember the GP9 experiments). E-8/9 drawings show that the "front" fan at both ends point down (into car body). They pulled air into the side ducts in the conventional system but it was not enough in the low Oxygen of high altitudes. So UP cut the extra opening on the top directly above the fan to allow a direct shot into the body and supplemented the standard flow. We had a diagram with colored arrows of this all ready to go for the E unit Streamliner articles but it was eliminated to limited color signatures of that era.
So now there was a 36" hole in the roof of the hatch sucking air directly down into the carbody. Therefore the snow shields. I spent an entire day in mechanical in Omaha looking for a diagram to show the modifications and the design dimensions of the shields. No Luck! I even talked to a retiree who said "the diagrams are in the file cabinet over to your left in either the bottom drawer on the on right above it". But no luck--gone home in someone's personal file I guess. The 951 as the Preamble Express had the shields removed because of restricted clearances on it's trip around the country. Several photos were published looking down from bridges that show the "holes" with the chicken wire grill.
And since their run of about 1989, Overland models has included these openings on their models of UP locos."
The structures on top of UP's 12 AiResearch turbocharged GP9s are definitely snowshields. On the AiResearch units, their sole source of intake air was on top of the units, through a filter box that contained eight of the standard 18 inch square oil soaked wire mesh filters. The drawings reproduced in the July 1988 issue of the UPHS "The Streamliner" magazine show this.
The carbody louvers would not have been blanked off, since open louvers would furnish the needed air for the generator cooling fan, and the two rear traction motor blowers. (This brings to mind that the two louvers on the equipment door under the GP7 cab may have been there to provide air for the two front traction motor blowers. Apparently, EMD found out that they were not needed, so on the GP9/18/20s, used a blank door instead.)
The air intake on an E8/9 was through the side grilles, via a duct that funneled the intake air up to the roof hatch, then down through the 36 inch intake fan and into the filter compartment. Maybe the intake fan and air filter compartment was EMD's early attempt at a pressurized carbody. After entering the car body interior, the intake air was used as combustion air for the diesel engine itself, and by the generator and traction motor cooling blowers. The combustion air was further filtered by a bank of oil soaked wire mesh filters mounted atop the Roots blowers.
Quoting Preston Cook (writing as W. A. Cuisinier) in Extra 2200 South, Issue 43, Nov-Dec 1973, p. 21:
"E8 air intake for engine and equipment blowers is rather novel. Located in the winterization hatch of each prime mover is a fourth 36 inch fan, similar to the three [radiator] cooling fans, but which blows air downward, into the carbody, through a filter compartment built into the roof hatch. Oil wetted wire mesh cleans the air just before it enters the engine room. This fan can draw air supply from either of two sources, from a duct thru which air enters the carbody behind stainless steel trim grill during summer, or in winter by switching (using handle in the engine room) the position of flaps inside the winterization hatch, it can draw warm air from the exhaust stream of the #1 radiator cooling fan. Unfortunately, like many other devices, this air system too can be completely circumvented by the same negligence, failure to replace the false ceiling panels."
He continues describing the dangers of having unfiltered air in the carbody, which can cause road failures by flashovers due to dirt-clogged electrical gear. There is also an excellent drawing that shows the flow of air through the roof top hatch, in both summer and winter positions. For those who are close, or who plan to be there on either vacation or business, the E8 model at the Smithsonian in Washington DC also shows this in section and cut-away.
This issue of X2200 also has several detail photos of the carbody interior of E8/9s, along with a cut-away drawing, and a complete E8 and E9 roster, including Amtrak, as of March 1, 1974.
On the GP units, the general intake air used by the electrical gear was filtered by the filters on the carbody doors, behind the louvers. As with the E8/9s, the engine combustion air was also further filtered by a bank of four standard 18 inch square filters mounted atop the Roots blower. The winterization hatch on a GP unit was not part of the intake air system as on the E8/9. On the GP units the hatch simply allowed heated radiator exhaust air to enter the carbody space above the front of the diesel engine (which was towards the rear of the locomotive). The lever to change from summer to winter was located on the hatch itself, and was held in either position by a bolt. This required the position to be changed by climbing up on the top of the locomotive.
The additional holes in the two GP9s were done for operating temperature reasons, not oxygen content reasons. They simply ran too hot (on Cajon Pass in California, not in Wyoming), and UP cut the holes to get more air flow to help them run cooler. The holes did not help, and the units ran at almost the same temperature. This is from Lloyd Edson, the head of the turbocharging program. Maybe, like on the GP9s, the hole in the top of the winterization hatch on E8/9s was done to help the units run cooler. The two programs would have been done during the same 1955/1956 time frame.
I guess the variations in explanations for the "snowshields" or "air flow disturbers" comes down to hear-say. Both reasons sound plausible to me. Very possibly, both are right, and it depends who you talk to as to which reason they themselves heard. Maybe they were put on for one reason, and the other was an added benefit. Only research into actual UP drawings and correspondence will answer the question, or possibly talking to someone directly involved in the program. In the meantime, I vote that we call them snowshields, because everyone already knows them by that name, wrong or not.
Ditch Lights
As part of the Amtrak Authorization and Development Act of 1992 (Public Law No: 102-533, October 27, 1992), the Federal Railroad Administration formally instituted a regulation that required ditch lights on all locomotives operating in the United States. The regulation required that by 1997, any locomotive operating faster than 20 miles per hour over public grade crossings must be equipped with a triangular-pattern of lights; one headlight and two "alerting" lights. Ditch lights had been in use for the past 40 years on Canadian railroads as an aid to crew safety, and are used to illuminate the side portions, the "ditches," of the railroad right of way on mountain lines with numerous curves. Based on statistics, the FRA hoped to eliminate as many as 3,300 grade crossing accidents over the following 20 years. (see also Trains magazine, Volume 56, Number 6, June 1996, page 20)
The following comes from the May 1996 issue of PacificRailNews, page 10:
FRA Issues Ditch Light Rule — Back in 1992, Congress directed the Federal Railroad Administration to require "substantially enhanced locomotive visibility measures"— that is, additional lights—in order to improve grade crossing safety. After several years of study and hearings, FRA published its final rules on March 6. These rules confirm the standard the industry has adopted—a triangular system of one headlight and two ditch lights. The ditch lights must be at least 60 inches apart, or 60 inches lower than the headlight. This requirement caused some controversy because Canadian National units, which often operate in the United States have ditch lights spaced 44 inches apart. FRA sidestepped the dispute by grand-fathering engines equipped with 44-inch ditch lights before May 30, 1994. Ditch lights must be at least 36 inches above the rail, except that lights on push-pull cab cars may be 24 inches above the rail. Flashing lights are permitted but not required. Locomotives operated over highway crossings at 20 mph less, and historic locomotives built prior to 1949, are exempt. All other locomotives must have ditch lights installed by the end of 1997.
Nine UP SD40-2s were equipped with what was then referred to as "Canadian-style" ditch lights in February 1978. Their numbers were UP 3396-3399 and UP 3410-3414. They were intended for assignment in the leading-position on pool trains with Canadian Pacific through Eastport, Idaho. The modifications were completed at Salt Lake City.
In early March 2008, new EMD SD70ACe units began to appear with ditch lights on their rear platforms. The details of this are as yet unknown.
North Little Rock snowplows
Beginning in about late 1997, UP began applying a new standard snowplow to the front of its road locomotives. This new design features an almost horizontal top portion of the snowplow and differs greatly from the previous design, which had an angled top portion. Locomotives with the new design received new snowplows at North Little Rock, and at Boise Locomotive Company.
Nose Door Windows on Safety Cab Units
Originally, windows were installed on the nose doors of safety cab units to allow a crew member leaving the cab to see a fellow crew member on the walkway prior to opening the door. In practice, however, on-coming crew members nearly always stayed on the ground until the off-going crew climbed off. It is also pretty difficult for two people with their grips and other necessary items, to pass each other on the front platform; there simply isn't room.
The first SD60Ms on UP to receive nose door windows from the factory were UP 6216-6267, delivered from September to November 1990. The earlier units, UP 6085-6215, were delivered in December 1988 to June 1989 without nose door windows, and the feature was added later by UP. UP's first Dash 8-40CWs began arriving in December 1989, numbered as UP 9356-9405, and were equipped with nose door windows right from the initial delivery.
A project to remove the nose door windows began during early 1999 because crews began to be concerned about foreign objects and material from a grade crossing collision entering the cab area through a broken nose door window. The most apparent units to have their nose door windows removed are the SD60Ms that are renumbered into the new 2240-2520 number series. As of mid October 2000, none of the renumbered safety cab units are known to have received the new wings medallion.
Union Pacific's Natural Gas-Fired Locomotive Program
"Union Pacific awarded Amoco Corporation a supply contract for a special blend of liquefied natural gas (LNG) to be used in UP's LNG-locomotive test program. The 3-year test, to be conducted in four long-haul freight and two yard locomotives, began in January. The fuel is 99 percent methane and burns cleaner than any other fossil fuel. UP's test program requires about 200,000 gallons of LNG per month. What will carry this fuel? New 30,000-gallon-capacity tender cars made by Process Engineering. The cars are 71 feet long and nearly 11 feet wide. They were unveiled during a ceremony at the company's Manchester, N.H., facility in November." ("Amoco Gets LNG Supply Nod", Changes [UPRR employee newspaper], Volume 7, issue 6 (November/December 1993), page 8; [photo caption] "First of six fuel tenders for LNG locomotives UP will place in service in 1994.")
"Amoco Production Co. is producing a special blend of liquefied natural gas at its Painter Complex Gas Plant in Evanston, Wyo., for Union Pacific Railroad's locomotive test program. Michael P. Fitzgerald of Amoco Corp.'s Alternative Transportation Fuels Business Unit, said, 'Union Pacific Railroad will be testing the LNG fuel to determine operating feasibility, environmental benefits and economics compared with diesel fuel.'" ("Amoco producing gas blend for Union Pacific", Deseret News, November 17-18, 1993, page B5)
UP 9554 and 9555 (built in December 1993) were modified by GE to burn natural gas. In a similar program EMD modified SD60s 6364 and 6365 (built in October 1992). Although converted to burn natural gas, all four units never formally entered service with the modifications. Sean Graham-White wrote on September 1, 2003, "Testing of both EMD and GE units were conducted at their respective plants (McCook and Erie). None of the four units or any of the fuel tenders actually touched the Union Pacific capable of operating on LNG. The fuel tender for the SD60Ms still sits at EMD's McCook plant."
The natural gas program (actually called LNG, for Liquefied Natural Gas) progressed no further than extensive engineering studies, and the program was cancelled due to increased costs for LNG, and technical difficulties with the locomotives themselves. All four units, two GE C41-8Ws and two EMD SD60Ms were placed in operation using diesel fuel. As a side note, UP 9554 had a plaque on its nose commemorating the safety record of UP's Salt Lake City shop.
The LNG tenders were numbered as UPT 1 to UPT 4. They were distinguished from UP's later diesel fuel tenders (UPT 5-8) by their longer length, and the enclosure along the tender's top. Photos of these four unique cars are extremely rare. Two LNG tenders (UPT 1 and UPT 2) were still in storage at EMD's facility in La Grange as late as March 2001; and again as late as September 2007. During late 2011, these two tenders were changed from UPT 1 and 2, to CNW 1 and 2. They were seen again on February 3, 2012.
Union Pacific's Fuel Tender Program
UP had four tank cars converted to serve as diesel fuel tenders. The cars were numbered as UPT 5 to UPT 8, numbered following the four LNG tenders (UPT 1 to UPT 4). The diesel fuel tender program was initiated in late 1995, placing a single fuel tender between two new General Electric C44ACs. The combination of a fuel tender connected between two locomotives was usually assigned to unit coal trains coming out of the Powder River Basin in Wyoming. The fuel tender program came to an end due to wear and tear on the fuel tenders themselves, since tank car frames are not designed to take the buffeting and differing longitudinal loads that locomotives are designed for. The tank cars used were standard tank cars, which are also not designed to take the high mileage of being coupled between locomotives (approximately 90,000 miles per year, about four times what a standard tank car would see). The program was in operation during from approximately July 1996 through May 1998 (date range supported by dated photos of fuel tenders in service). All of the fuel tenders were out of service by April 2000, and stored at Council Bluffs at UP's Fox Park passenger facility. They were still there as late as June 2002. (part from Trainorders.com, January 26, 2006; see also an article by Michael McGowen in "Union Pacific Modeler", Volume 3, pages 84-91)
The diesel fuel tender program was assigned to a total of 10 GE units; C44ACs UP 6840-6845 (six units) and C40-8Ws, UP 9387-9390 (four units).
This was posted to Trainorders.com on February 1, 2001:
The tenders were tested beginning in May 1996. They were made from Class O-70-1 tank cars from the 70000-70199 number series. The tenders were numbered UPT 5 through UPT 8. The tank cars were originally built in the 1954-55 timeframe by American Car & Foundry. The cars were modified by Union Tank Car in Muscatine, Iowa. The cars were 51 feet long and had a capacity of 19,167 gallons.
UP fuel tenders UP 6 and UP 7 were stored at Cheyenne, Wyoming, as of April 10, 2009.
UP assigned a total of six new GE C44CW (AC4400W) locomotives to their diesel fuel tender program. Their numbers were UP 6840-6845, built in October 1995. Several news reports also show four C40-8Ws, UP 9387-9390, built in February and March 1990, as being part of the program, but these were just planned and not actually converted.
At about the same time, in late 1994, CSX announced that they would also investigate the use of fuel tenders, having them connected to new GE AC4400CWs 28-30.
The most famous diesel fuel tender program was BN's, which put fuel tenders into regular service. Beginning in October 1982, with 27 tenders being in use by 1984, BN's (and later, BNSF's) fuel tenders and matching SD40-2s (and later, SD60Ms) were used in helper service on unit coal trains leaving Wyoming's Powder River Basin, a service they remain in as late as September 2005. Initial success, with 78 fuel tenders in service by November 1988, was followed by later cutbacks; by June 1991, only 26 remained in service.
Smaller fuel tenders were used along BN's northern mainline, connected between GP50s, GP40-2s, GP38-2s, B30-7s and leased LMX Dash 8 40Bs. (For additional information on BN's program, see Robert Del Grosso's 1980-1991 BN Annual; also see this great on-line article about BN's fuel tenders by Paul Birkholtz and Al Krug.)
EMD Cabs on MP Units
The following MP units received EMD cabs as part of wreck damage repairs while still in service on MP, prior to merger with UP. (list from Zack Hilton, via email to LocoNotes on February 2, 2001)
| Model | First Number | Second Number |
| U30C | MP 3311 | MP 2976 |
| U23B | MP 2256 | MP 4506 |
| U23B | MP 4521 | |
| U23B | MP 4528 | |
| U23B | MP 2282 | MP 4531 |
| U23B | MP 4534 | |
| B23-7 | MP 2296 | MP 4607 |
Air Horns and Sirens
UP 3049 was equipped with an electronic siren. The following comes from UP Bulletin A-300, dated August 6, 1975 (courtesy of Mark Amfahr):
Unit 3049 has been equipped with an electronic siren on a test basis. This siren is to be used as an emergency vehicle only and in no way alters the requirements on use of the regular horn. The operator has a selection of three sounds: WAIL, YELP or HIGH-LOW and may be used individually or in a series. It is intended that the siren be sounded approaching and passing gangs or workmen on or near the track and is not intended to be used in cities, towns , municipalities or grade crossings except in emergency.
UP SD40 3049 involved in test program to use air raid-type for sirens to better alert track crews. (CTC Board, January 1976, page 8)
UP SDP35 1402 was equipped with air raid-type siren, made by Federal Signal, to increase alertness of track maintenance crews. SDP35 1400 also equipped with same design. (Pacific News, May 1978, page 16; Pacific News, August 1978, page 15)
Siren was removed from UP SDP35 1402. (Pacific News, January 1979, page 14)
Air raid type sirens have been removed from SDP35s 1400 and 1402. They will be reinstalled on 6900s. The first to get them was 6918. (Pacific News, March 1979, page 16) UP 6918 retained its siren while in storage in Yermo, California, from January 1982 through its retirement in 1985.
Air raid siren from SDP35 1400 has been installed on 6924. (CTC Board, May 1979, page 8; Pacific News, May 1979, page 22)
All new units to be delivered with horns mounted on cab roof. (Pacific News, August 1978, page 15)
Journal Boxes
Question: Has anyone figured out the reason for these different designs of roller bearing journal boxes that EMD used on a lot of early units? Why was there usually one of each on each axle, rather than all journals being the same?
Answer: Half of the roller bearing business went to Hyatt (a division of GM), and half to Timken (a direct competitor of Hyatt's). Probably due to a shortage of materials during and after the war.
The square ended journal boxes could have a speed recorder drive mounted into it. Not possible with the sloped front journal box. Inside the journal box was a thrust block to absorb the lateral shock of the lateral movement of the axle (traction motor). In the square boxes the spring plates that supported the thrust block had a hole through it for the speed recorder spline drive. The plates in the sloped boxes had no holes. The boxes were totally interchangeable except for the option of applying a speed recorder drive.
When applying a traction motor to the position of the speed recorder drive, the axle had to have a splined hole in the center of the axle. Not all traction motors have the splined hole in the end of the axle.
On the Union Pacific all the oil bath journal boxes were Hyatt and all the sealed grease boxes were Timken.
Toilets
UP 3794 was fitted with rear toilet enclosure in February 1982 through November 1990. The modification was done as a test to alleviate crew complaints about odor from toilets installed in the low noses of UP's other units, but was unpopular with the crews due to safety concerns while accessing the new lo action during inclement weather at track speed. To save maintenance costs, the enclosure's access door was welded shut by mid 1985, and was removed completely in November 1990 when 3794 was rebuilt as one of the prototype units of the SD40-2 Life Extension Program, which rebuilt as total of 423 units between late 1990 and late 1999.
48-inch Radiator Fans on GP9s
For several years from the early 1970s through to the late 1990s, I thought that Union Pacific GP9 cab unit number 321 was the first GP9 on UP to receive 48-inch radiator fans. I was mistaken.
Back in 1972 or 1973, I was in the EMD parts warehouse in Ogden, Utah. In the foyer, they had a full set of EMD parts catalogs (in the standard, flip-up EMD catalog rack). In the same rack, there was a set of an EMD sales department newsletter, called "Inside EMD." It contained all kinds of interesting stuff, especially from the early 1950s. One bit of information I've always remembered was it called out specific orders when options were available, or no longer available.
On the subject of "Inside EMD", Preston Cook, a historian of EMD locomotives, wrote:
Inside EMD was originally introduced as a Parts Department newsletter to notify customers and field sales personnel of the availability of new and improved parts, special deals on parts through sales or inventory closeouts, or of matters of policy pertaining to the sales and marketing of parts. The publication was introduced in the middle of 1953 and issues appeared at irregular intervals for several decades. The name “Inside EMD” was subsequently adapted in the 1980s for the internal company newspaper.
The original "Inside EMD," printed in the 1950s and 1960s, was one of the most basic of the EMD internal commercial publications. It was printed on inexpensive paper and seldom included any photographs. However it frequently contained technical information that was not conveyed in any other publications.
One small item that I recall seeing during my visit to the EMD Ogden warehouse was that the first GP9 to receive 48-inch radiator fans was order number 5552-21. I wrote the info on a scrap of paper and headed home. Using my recently acquired copy of the EMD 1972 product reference, I looked up order number 5552. I found that it was for UP 300-349 and 300B-349B, built in July to October 1957, and that 5552-21 was UP 320, being the 21st unit of order 5552. Later research found that EMD regularly made arrangements to retrofit previous units in a particular order to the latest configuration, meaning that UP 300-319 likely received 48-inch fans after leaving the factory. I had not seen a builder's photo of any of these unit to verify that assumption that UP 321 was the first.
Back in May 1999, while doing research among photographs of Union Pacific diesel locomotives, I noticed that the 300s were delivered with 48-inch radiator fans. That break between 321 (built in July 1957) and 322 (built in September 1957) was where I thought the break was between those delivered with 36-inch fans and 48-inch fans, according to that EMD publication I saw 25 years before, making me think that the units delivered with 36-inch fans were retrofitted within six months with 48-inch fans (I mentioned this in a photo caption for the photo of UP 300, taken in April 1958, in my article in Diesel Era about UP's turbocharged GP9s). I discovered that this was wrong after looking again at Harold Ranks' photo of UP 306 being delivered in July 1957. The photo shows the unit with 48-inch radiator fans, and, by the way, also showing that the 300s were the first units with silver trucks.
I've often wished that I had paid better attention to those books in the EMD warehouse. They closed their Ogden warehouse in about 1978, when they opened their warehouse in Commerce, California.
Regardless of which radiator fans were used, a feature also discovered in 1999 was that UP 300-321 had the single large louver set on the battery box doors, and 322-349 (and 300B-349B) have the two small groups of three louvers, like the later GP18s and GP20s.
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