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WP GP20 History
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Western Pacific GP20 History

EMD WP GP20 Builders Plate
Photograph of Western Pacific GP20 2001 Builder's Plate.

Specifications     Unit Dispositions     History     Sights & Sounds    References
A Sad Ending     Learn More

Western Pacific GP20 Specifications:

  • Builder - EMD 2000 Horse Power Road Switcher
  • Total Loaded Weight - 256,900 lbs (first order)
  • Total Loaded Weight - 257,000 lbs (second order)
  • Diesel Engine - 16 Cylinder Turbo Charged 567 D2, Two Cycle with a 14 1/2:1 Compression Ratio
  • New D22 Model Main Generator
  • Upgraded D47-B1 Traction Motors
  • Wheel arrangement - B-B with Blomberg trucks
  • Western Pacific Road Class - 2001
  • Western Pacific Symbol - RS-64

Western Pacific GP20 Dispositions:

Color notes: SO - Silver & Orange    GRN - Green    NI - New Image Green & Orange

Unit No Date Built Serial Number/
Frame Number/
Order Number
11/1959 25623/
First production GP20
Retired by UP 3/1985
Preserved by FRRS at Portola, CA (6/1985)
12/1959 25624/
Retired by UP in 3/1985, sold to RELCO in 3/1988
RLCX 2001. Rebuilt with low nose 7/1988
Leased to EXXON at Shute Creek, Wy. (9/1988)
2003SO 11/1959 25625/
Wrecked at Beowawe, NV 9/1963
Traded to EMD for GP35 order 9/1964
11/1959 25626/
Retired by UP 3/1985, sold to PNC, Mt Vernon, IL
Scrapped by NRE 2003
11/1959 25627/
Retired by UP 3/1985. Sold to PNC, Mt Vernon, IL
Scrapped by NRE 2003
11/1959 25628/
Retired by UP 3/1985, sold to PNC, Mt Vernon, IL
Scrapped by NRE 2003
7/1960 26041/
Retired by UP 3/1985, sold to PNC, Mt Vernon, IL
Scrap Line Mt. Vernon, IL 8/19/1989
7/1960 26042/
Retired by UP 7/1983
Sold for scrap to Durbano metal, Ogden, UT 11/1985
7/1960 26043/
Renumbered and painted to UP 488 9/1984
Retired by UP 3/1985. Sold for scrap to St. Louis Auto Shredding East St. Louis,IL 11/1985
7/1960 26044/
Only GP20 painted in New Image paint 1982
Retired by UP 3/1985. Sold to PNC, Mt Vernon, IL
Scrap Line at NRE 2003

Western Pacific GP20 History:

The WP became the first buyer of the EMD GP20, when introduced in 1959, with an order for six units. The GP20 was an important milestone in locomotive design, they were EMD's first step into turbocharging as a means to increase horsepower. EMD advertised that the new GP20 would reduce scheduled maintenance time by about 60% and increase freight speeds using fewer units (3 for 2 replacement). Numbered in the 2000 series, based on their horsepower, they were numbered 2001-2006 and were bought as additional power with no trade-ins or retirements. The 2001 was the first production four axle locomotive for this model.

These first six units entered service in December 1959. Acknowledging that their FT fleet was reaching the end of their usefulness, a second order for four more GP20s was received in July 1960; they were similarly equipped and numbered 2007-2010, with four FT units provided as trade-ins. The Western Pacific was the smallest road to buy new GP20s and also bought the smallest number. These facts underscored the WP's position among the big Western roads; if it was to keep its business, it had to be competitive and owning the new GP20 was perceived to be a move to support its position.

All ten units were painted in the California Zephyr inspired orange and aluminum scheme with black stripes on both ends. The lettering style used was called Zephyr Gothic. The units were equipped with dynamic brakes, winterization hatches and dual controls (made them suitable for local trains, switching, and mainline service). They featured high short hoods (high short hoods were only built for the Great Northern and the Western Pacific), as the WP had not embraced the new style, unlike its close neighbors, the Southern Pacific and Union Pacific.

One small feature that set this small fleet apart was Western Pacific's choice of the single beam Pyle-National headlight, which protruded from the hood ends. The earlier GP7 and GP9s had come equipped with these headlights and the road was so enamored with them that the subsequent purchases of low-nose GP35s and GP40s also came with them.

They also came equipped with Nathan M5 five chime horns and 2,350 gallon fuel tanks. The units were ordered in two orders; the first were numbered from 2001 thru 2006 and the second order was numbered 2007 thru 2010. Both orders were identical in all respects (phase Ia), except the second group was 1,110 pounds heavier. The first order per unit cost was $212,793 with no trade in allowances. The second order per unit cost was less due to the fact that four FT units were traded in on the new order and EMD gave a trade in allowance of $17,000 per unit.

Little changed on the GP20s aside from the color scheme as the silver and orange was phased out. After a change of management in 1970, which brought Alfred Perlman from the Penn Central to the WP, the flashy Zephyr colors disappeared - replaced by a solid green (referred to as Perlman Green) with orange trim and nose stripes. The stripes were in the same pattern as that from the original Zephyr colors. This scheme was further simplified with "WP" initials on the noses with a couple of angled stripes one each side. One unit, the 2010, was painted into the New Image paint scheme just before the merger with the Union Pacific.

EMD WP GP20 SO Drawing
EMD WP GP20 GRN Drawing
EMD WP GP20 NI Drawing

Images courtesy of Jacques Bélander ©2000

After only three years of service, one GP20 was wrecked and retired; the 2003 was wrecked on September 14, 1963 at Beowawe, NV, and traded in a year later for GP35 3011. The purchase of second-generation GP35s, brought the predicted downgrading of the GP20s to "ordinary" Geep status. They became the normal power on Western Pacific locals and occasionally could be seen on subsidiaries Tidewater Southern and Sacramento Northern.

In 1982, the WP, along with the Missouri Pacific, was merged into the Union Pacific. This accelerated the demise of this small GP20 fleet as they saw only a few more years of use, mostly still on their own home rails. The 2008 was retired by UP in 1985 and only one unit, the 2009, was re-lettered and renumbered for the Union Pacific. This unit became UP 488, taking the number of a UP GP20 that had been retired. This unit and the other former WP GP20s lasted only a short time, all being retired in March 1985. Most of the units were sold to Precision National Corporation and stored at their Mount Vernon, IL site. PNC was purchased by National Railroad Equipment Co and they scrapped the units in 2003.


An EMD GP20 advertisement, the sale of the last 4 units Western Pacific purchased.

WP EMD GP20 Operating Manual Cover

A recent addition to my collection is a copy of a WP GP20 Operating Manual. As stated in the introduction, this manual was prepared to serve as a guide to railroad personnel engaged in the operation of the 2000 horsepower General Motors Model GP20 turbocharged diesel-electric locomotive.

Sights and Sounds:

Here is a sound clip of WP 2001, courtesy of Sam Herschbein, that was recorded at Portola in 1996.

Click the Play Button to start.


  • Melvin, George "GP20: The First Turbo Geep - Part 8: Union Pacific & Western Pacific" Model Railroading July/Aug. 2000: 20 - 24.
  • Peck, Dave "GP20: Start of a New Generation" Mainline Modeler Jan. 1986: 55 - 62.
  • Ryczkowski, John "Western Pacific GP20's" Prototype Modeler Nov. 1985: 27 - 31.
  • "EMD's GP20" Diesel Era July/Aug. 1998: 38 - 55. Withers, Paul K. GP20 and SD24 - EMD's Turbocharged Duo, Halifax.: Withers Publishing, 1998.
  • Solyom, Pete "Modeling the Western Pacific GP" Model Railroading Sept. 1996: 28 - 31.
  • Kamm, Al Jr "Electro-Motive's GP20" Model Railroader July 1963: 36 - 38.

Sad Ending:

A postscript on the demise of the GP20's at PNC/NRE as described by Eugene Vicknair (FRRS member). The FRRS had contacted PNC/NRE in the late summer of 2002 and were told that the GP20's were still around, although very stripped. Eugene had them do a visual inspection on the units and received a report on the condition of several of the units, including the 2010. When Eugene went on a parts search for the WP Silver Hostel in the Midwest in the spring of 2003, one of his stops was to be the NRE facility at Mt. Vernon to look over the GP20's to see if there was anything salvageable. For several years, their had been talk of saving the 2010, as it was the last WP GP20 and the only one painted in the new image scheme. Eugene was about an hour away from the NRE facility, when a foreman from NRE called. He had some very bad news. The foreman had gone out to check on where the units were located that morning and could not find them. He returned to the office and asked if anyone knew where they were located. He discovered that the scrap line had cut them up and had never reported it to the office staff. It seems that they had been gone for a couple of months (at least) and no one had updated the office or the salespeople. All that remained was the frame of the 2010, used as a flat car to move parts around the yard. A sad ending indeed. I am fortunate to have pictures of the WP 2010 photographed by Merrill Thurman at NRE in 2002.

Would You Like to Learn More?:

Please visit the Western Pacific Railroad Museum at Portola's web site, it is a must for those interested in the Western Pacific Railroad.