Union Pacific GP7s
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This page was last updated on July 4, 2015.
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.
All of UP's GP7s were renumbered from the 700-729 series, to the 100-129 series , in late 1953. (Full roster Listing of UP's GP7s)
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 electrical 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.
UP 100-109 had one high door, while 110-129 had all-low doors. UP 105-109 were built in March 1953 on the cusp of the change in door configuration. Number 100 had the high door, but it was built in February 1953.
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.
High Number Boards
The first order of UP's GP7s, 700-709 (renumbered to 100-109) had high number boards 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.
On many occasions, while working for UP, I looked at the inside of the hood ends. There was no indication that the low number boards were a UP modification due to the factory appearance of the area around the openings. There was no indication on the outside either, that the low number boards were cut into the hood later. This puzzles many people, especially when there are photos of single units with high number boards, i.e., 102, 103, 121.
Number 121 may have had low number boards, but at some later date, wreck repairs may have put them back in the high location. Or maybe it had its hood swapped with a unit that had high number boards.
Photos in which the short hood end is visible all show the number boards at that end as being in the high location.
Photographs show 129 with no evidence of ever having high number boards and 128 with a Gyralite installed in 1970. One picture of 709 (later 109) shows high number boards on that unit, same for 102.
Some observers believe that the first order, numbers 700-709 (renumbered to 100-109) had high number boards 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.
All of the photos in George Cockle's book show the lowered number boards, as do all the in-service shots. But I've seen a builders photo (unnumbered) with high number boards.
The theory proposed in The Streamliner was that numbers 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 show number 102 and 103 with high boards in the 1970s, so they must not have ever been lowered.
Photograph research generally supports the assumption that the first order (100-109) came without low number boards 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.
Exhaust Stack Extensions
The exhaust stack extensions were 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.
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).
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.
Major Features of UP's GP7s
|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|
|102||?||high||Y||Y||SL, 11-2, p.28|
|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||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|
|106||1954||high||Y||N||Signor, LA&SL, p. 183, high stacks|
|106||5/26/75||low (d)||Y||N||UP 1992, p.99|
|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|
|110||7/69||low||Y||Y||N||Jack Taylor photo, via Mike Clark|
|115||1955||high||Y||N||SL, 8-2, p.29|
|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||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||4/6/79||low (d)||Y (r)||Y||UP 1977-1980, p.33|
|121||5/4/72||high||JH; (the reason for UP 121 having high number boards rather than low number boards like the others in its 120-129 group, is unknown; possibly due to a wreck repair effort by EMD)|
|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|
|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
"Union Pacific GP7 Diesels", by Steve Orth, Railmodel Journal, Volume 12, Number 12, May 2001
Mainline Modeler, October 1982: GP7 Phase 1, includes cross section of fuel and water tanks
Mainline Modeler, January 1983: GP7 Phase 2, includes cross section of fuel and water tanks