Union Pacific GP7s
By Don Strack
UP's first GP7s were ordered in October 1952 as part of a larger order with EMD that included 22 E8 passenger locomotives (eight A units, to be numbered as UP 931-939, and 14 B units, to be numbered as UP 931B-944B, along with 22 1,200 horsepower SW9 switch locomotives, to be numbered as UP 1825-1846. (AFE 301, approved October 13, 1952)
These first 10 GP7s were originally to be numbered as D.S. 700-709, matching the earlier scheme of designating all switcher and road-switcher locomotives as Diesel Switch units. The decision to remove the D.S. designation was made in February 1953, the same month that the first GP7 was delivered. All ten units were delivered in February and March and may have been delivered with the D.S. prefix. A photo of UP 709 shows the unit with an obvious patch of fresh yellow paint under the 709 road number on the front angled hood end. This may indicate that the unit was renumbered from D.S. 709 to just 709 by UP after its delivery.
Cab Heating
Rich Sievers wrote the following on Trainorders.com on July 27, 2001:
As built, GP7s and early GP9s had a crappy cab heat system that routed "heat" into the cab. The #1 fan had a switch on the electrical cabinet panel in the cab that turned it ON or OFF. The shutters below the #1 fan were manually operated from the cab.
In theory, to obtain cab heat, one would turn the "#1 Cooling Fan" switch OFF and CLOSE the shutters. In theory, heat would then enter the cab through a duct system in the ceiling. There were a couple of blowers mounted on the electical cabinet that would, in theory, blow the heat into the cab.
Notice how many times I said, "In theory". That'll give you an idea as to how well the system actually worked.
During warm weather when more engine cooling was needed, one could turn ON the "#1 Cooling Fan" switch and OPEN the shutters.
In the photo of the 1226, I reckon the #1 fan and shutters were plated over in an attempt to provide a little bit of cab heat.
Information from email posted to the Diesel Modeler's List during October 1998:
[Scott Chatfield] UP 100-109 had one high door (early Phase Two in Dover's system, late Phase One in mine), while 110-129 had all-low doors (Phase Two in my system). Actually, I would like confirmation that 105-109 had the one high door. They were built in March 1953 on the cusp of the change. I know that #100 had the high door, but it was built in February 1953.
These first few can be made from the new P2k GP7, but they also have the very distinctive low numberboards on the long hood. They also had signal lights (look like Pyle Gyralites) early in their careers. I wonder when they were removed?
[Terry Roberts] The pictures of 100, 102, 103 and 109 show one door in front of the cab as higher than the others. On 124, 128 and 129 have these doors are the same height as the others. There are no pictures of 110-119 in this article.
[Scott Chatfield] One picture of #100 taken in 1975 shows plates over the original high number boards and the Gyralite location. Photos of 103 show the numberboards in the high position. I don't believe the numberboards on 103 were ever moved to the low position as a July1981 photo shows the number boards in the high position with no sign of a coverplate over the low position. the Gyralite has been removed before this time. Other pictures show 129 with no evidence of ever having high number boards and 128 with a Gyralite installed in 1970. One picture of 709 shows high number boards on that unit, same for 102.
In the same issue is a statement of a theory that the first order, 700-709 (renumbered to 100-109) had high numberboards when delivered and the other 20 units were delivered with low number boards. Some of the first 10 units had the number boards lowered, but obviously not all were changed as the pictures of 103 show no evidence of a position change through July 1981.
[John Henderson] My October 1973 photos of UP 105 (right side of hood) and UP 109 (left side of hood) show a single high door between the dynamic brake blisters and the cab. This matches my 1967 photos of UP 100, 101, 102, and 103. I have 28 negatives of UP GP7's covering the years 1967 to 1973 and all show the "Gyralite" on the locomotives, apparently on both long and short hoods.
[Scott Chatfield] All of the photos in Cockle's book show the lowered numberboards, as do all the in-service shots I've seen show. But I've seen a builders photo (unnumbered) with high numberboards. So it looks like a UP mod.
[Don Strack] On many occasions, while working for UP, I looked at the inside of the hood ends. There was no indication that the low numberboards were a UP modification (you can tell by the quality of workmanship - UP's boilermakers are not known for fine detail). There was no indication on the outside either, that the low numberboards were cut into the hood later. This has always puzzled me, especially when there are photos of single units with high numberboards, i.e., 102, 103, 121.
By the way, the exhaust stack extensions are 24 inches, with 6 inch high by 3 inch gussets at the base for strength. I measured them one day while on top waiting for a crane to lift off a radiator hatch.
[Steve Orth] The theory proposed in The Streamliner was that #100-109 were delivered with high number boards and some were subsequently lowered. Photos in The Streamliner article clearly show the welds where the high number boards were filled and repainted. Other photos that I have show #102 and 103 with high boards in the '70's, so they must not have ever been lowered.
The theory continues that #110-129 were delivered with low number boards. But, your photo of #121 kinda messes that up, unless the long hood end was swapped out due to a wreck or something.
[Don Strack] The wreck repair idea works for me. But UP 121 had stack extensions right up until its retirement in Sept 1984 (I saw it going through Salt Lake on its way to Omaha). If it was a wreck repair, then it was repaired at EMD, with a new hood. I can guarantee you that if the new hood was put on by UP, the stack extensions would not have been transferred. While the stacks were bolted on with six bolts, I don't see anyone in any UP shop going to the effort of swapping one stack cover (our name) for another, unless the new hood came without (maybe, maybe not).
Before I get too hyped up here, I better go home and read the Streamliner article again.
[Scott Chatfield] The two stacks don't have the same mounting bases? What was the purpose of the extended stacks in the first place?
[Don Strack] On EMD GPs and Fs, there were actually two stacks. The actual exhaust stack was attached to the diesel engine itself (Walthers did a great job on their model of a 567), and extended up through the car body roof. The other *stack* was attached to the exterior of the car body roof. On the F units, the *stack cover* was slightly flared. On the GPs, it was straight. Both were about eight inches tall, and formed from two pieces about 1/8 inch sheet metal, with the weld bead running the along the edge, forming the flattened oval shape that we know as exhaust stacks. The flattened oval was then welded to the mounting base, which was about 18 inches by 12 inches, with ten 1/2 inch holes around its perimeter, one at each corner and two along the long edge and one along the short edge. The cover plate was bolted to the car body roof using these ten holes and 1/2 hex-head cap screws (heads are 3/4 inch diameter).
My comment doubting whether or not UP would have transferred its extended exhaust stacks from a wrecked GP7 long hood to a replacement long hood concerned these stack covers. They may have transferred them, but I doubt it.
I spent about eight hours this weekend going through all my UP Streamliners, plus all my other UP books, looking for photos of GP7s (plus getting sidetracked reading about all sorts of interesting things). I have compiled a list showing the details, i.e., high number boards (front/rear), low number boards (front/rear), with or without access doors below the number boards, Gyralite (front/rear), snowplow (front/rear). The research generally supports the assumption that the first order (100-109) came without low numberboards and access doors, and the other two orders (110-119 and 120-129) came with, except 121, for some unknown reason. UP 128 and 129 did for sure, along with tall stacks.
To answer Scott Chatfield's question about why tall stacks. The answer to the question about tall stacks on both the GP7s and the SD7s is one that has escaped all UP historians that I have talked to. My own guess is that since they would be operating long hood forward, they wanted the tall stacks to keep the exhaust out of the cab. The problem with this is the fact that the Alco RS2s and RSC2s, delivered five years before, did not have tall stacks. Then again, maybe it was because of the experience with the Alcos that they had the tall stacks on the EMDs. By the way, the tall stacks I saw were not welded-on extensions, they were fabricated as 24 inch tall stacks, compared to the regular eight inch stacks. The stacks on some of the SD7s were later cut down to 18 inches. I'm sure of the two numbers (24 inches and 18 inches) since I did the actual cutting on two of them. The lower stacks were needed because six SD7s were assigned to the Clearfield Freeport Center in Northern Utah to allow the units to enter the buildings while switching.
Rich Sievers wrote the following on Trainorders.com on January 22, 2001:
The UP's GP7s were set up with the long end designated as the "front". They originally had Mars signal lights mounted on both ends, which resulted in the headlight assembly being lowered.
The number boards on the long hood end were at the level shown in the photo to allow better access when changing the indicators. Changing the indicators was somewhat difficult with the number boxes at the "normal" height, as one had to work around the bottom of the radiator and associated piping, the sand box and sander pneumatic valves, and air compressor. It usually involved standing in leaking oil and water, as well. At the lowered position, the indicators were much easier to reach. If you'll look closely at the photo, you'll see there were also small access doors below the number boards at allow the indicators to be changed by reaching in from outside.
The number boxes on the short hood were at the normal height, as it was fairly simple to change the indicators on this end from inside the short hood.
There wasn't a problem reaching the indicators on the SD7s, which were also set up with the long hood as the "front", as there were access doors around the class lights that could be opened. It was a simple matter to climb up the ladders, open the doors, and reach down.
Further reading:
"Union Pacific GP7 Diesels", by Steve Orth, Railmodel Journal, Volume 12, Number 12, May 2001
Major Features of UP's GP7s
| Road Number |
Photo Date |
Numberboards | Gyralite | Snowplow | Notes | |||
| Front | Rear | Front | Rear | Front | Rear | |||
| 100 | 10/58 | high | Y | N | LS | |||
| 100 | 9/67 | low | JH | |||||
| 100 | 9/74 | low | high | Y | Y | N | N | Two photos by Jack Taylor, via Mike Clark |
| 100 | 7/6/75 | low (d) | Y (r) | N | SL 11-2, p.30 | |||
| 100 | 6/26/78 | low (d) | Y (r) | N | UP 1977-1980, p.33 | |||
| 101 | 11/7/67 | low | JH | |||||
| 102 | ? | high | Y | Y | SL, 11-2, p.28 | |||
| 102 | 6/72 | high | JH | |||||
| 103 | 11/62 | high | Y | N | N | SL, 11-2, p.31 | ||
| 103 | 7/69 | high | Y | N | N | Jack Taylor photo, via Mike Clark | ||
| 103 | 4/70 | high | Y | Y | N | N | SL, 11-2, p.31 | |
| 103 | /71 | high | Y | Y | cast plow, Jack Taylor photo, via Mike Clark | |||
| 103 | 5/18/73 | high | JH | |||||
| 103 | mid 70s | high | Y | Y | SL, 11-2, p.37 | |||
| 103 | 7/81 | high | Y (r) | Y | SL, 11-2, p.34 | |||
| 103 | 7/81 | high | Y(r) | Y | cast plow, Mike Clark photo | |||
| 103 | 8/82 | high | Y (r) | Y | SL, 11-2, p.34 | |||
| 105 | 10/73 | low | JH | |||||
| 106 | 1954 | high | Y | N | Signor, LA&SL, p. 183, high stacks | |||
| 106 | 5/26/75 | low (d) | Y | N | UP 1992, p.99 | |||
| 106 | 2/71 | high (d) | Y | N | LS | |||
| 707 | 3/4/53 | high | high | Y | Y | N | N | new, short stacks |
| 107 | 1962 | high (d) | Y | N | SL, 5-1, p.6 | |||
| 709 | ? | high | Y | N | SL, 11-2, p.26, short stacks, renumbered from something else to 709 (yellow patch on angled hood end) | |||
| 109 | 1954 | high | Y | N | Signor, LA&SL, p. 183, high stacks | |||
| 109 | 10/73 | low (d) | JH | |||||
| 109 | 8/74 | low | N | LS | ||||
| 110 | 7/69 | low | Y | Y | N | Jack Taylor photo, via Mike Clark | ||
| 111 | 2/11/74 | low | JH | |||||
| 111 | 6/74 | low (d) | Y | N | LS | |||
| 112 | 8/4/72 | low | JH | |||||
| 113 | 7/28/68 | low | JH | |||||
| 114 | 1/23/72 | low | JH | |||||
| 115 | 1955 | high | Y | N | SL, 8-2, p.29 | |||
| 115 | 7/13/68 | low | JH | |||||
| 115 | 1/23/72 | low | ||||||
| 115 | 10/73 | low | ||||||
| 717 | 9/19/53 | low (d) | Y | Pfeifer, p. 35 | ||||
| 117 | 5/2/73 | high (d) | Y | N | X2200, 67, p.26 | |||
| 117 | 6/6/73 | low (d) | Y (r) | N | UP 1977-1980, p.33 | |||
| 719 | 9/4/53 | low (d) | Y | N | new, short stacks, SL, 1-4, p.23 | |||
| 119 | 7/24/67 | low (d) | Y | N | UP 1968-1977, p.104 | |||
| 119 | 7/28/68 | low | JH | |||||
| 119 | 8/72 | high (d) | Y | Y | N | N | Jack Taylor photo, via Mike Clark | |
| 119 | 6/6/73 | high (d) | Y (r) | N | UP 1977-1980, p.33 | |||
| 120 | 10/73 | low | JH | |||||
| 120 | 4/6/79 | low (d) | Y (r) | Y | UP 1977-1980, p.33 | |||
| 121 | 5/4/72 | high | JH | |||||
| 122 | 4/68 | low | ||||||
| 123 | 10/67 | low (d) | Y | Y | Jack Taylor photo, via Mike Clark (large plow) | |||
| 124 | 7/2/72 | low (d) | high (d) | Y | Y | Y | N | SL, 11-2, p.27 |
| 125 | 12/2/77 | low (d) | Y (r) | Y | UP 1977-1980, p.31 | |||
| 127 | 4/15/79 | high | Y (r) | N | UP 1977-1980, p.32 | |||
| 128 | 6/72 | low (d) | Y | Y | UP 1968-1977, p. 53 | |||
| 128 | 8/22/70 | high (d) | Y | Y | Y | N | SL, 11-2, p.32 | |
| 128 | 12/27/67 | low | JH | |||||
| 129 | 11/6/53 | low (d) | high (d) | Y | Y | N | N | new, tall stacks, SL, 11-2, p.32 |
| 129 | 10/4/58 | low (d) | Y | Y | N | SL, 11-2, p.32 | ||
| 129 | 5/70 | high (d) | Y | Y | Y | N | Jack Taylor photo, via Mike Clark (large plow) (steam generator) | |
Y = yes
N = no
low = low number boards
high = high number boards
(d) = access doors below number boards
(r) = Gyralite removed
JH = John Henderson
SL = The Streamliner
LS = Lou Schmitz
X2200 = Extra 2200 South
