my ESPEE MODELERS ARCHIVE
California's Railroad to the U.S. 1861 - 1996
Southern Pacific GP20
P2K by Ken Perry
P2K by Ken Whitehead
Southern Pacific GP20 Data: from the SP Mailing List courtesy and © Rob Sarberenyi, (and used here with permission).
I've been studying EMD GP20's in anticipation of P2k's HO scale model due in July. Looking through the information and photographs, I offer the following data for Espee and SSW modelers interested in these units regarding their as-built configuration. Interestingly enough Extra 2200 South doesn't specify phase designations for GP20's, despite noticeable spotting changes and a significant difference in the frame/skirt treatment on GP20's built from January to April 1962, the last of this model built prior to start of GP30 production. Phase designations listed below are my own applications.
P2k's GP20 represents Phase 1a units (judging from the photo on their Web site), and by changing the radiator fans, Phase 1b's can be modeled. The only Phase II units built by EMD comprise SP #7200-7233 (re #4050-4083 in the 1965 system renumbering).
GP20 Phase 1a
SSW #800-809 (re #4030-4039) blt. 12/60 and 1/61:
SP #7234-7237 (re# 4084-4087, ex-EMD demos #5625-5628) blt. 8/60:
GP20 Phase 1b
SSW #810-819 (re #4040-4049) blt. 12/61 and 1/62:
GP20 Phase II
SP #7200-7234 (re #4050-4083) blt. 1-4/62:
Phase II GP20 eliminated the distinctive frame perforations, introducing the thin frame that would follow with the later GP30's (starting in 1962) and GP35s (1964). SP received the only Phase II GP20's built. This will require some work for modelers wishing to replicate these Espee units using P2k's model.Sources:
Mainline Modeler article contains near broadside photos of EMD demos 5627 (engineer's side) and 5628 (fireman's side). These were two of the four demos Espee purchased, becoming #7235 & 7236 (#4085 & 4086 in 1965). I found photographic evidence the winterization hatch on ex-demo units was still in place into the 1980's. Also in the MM article is a b&w builders photo of SSW 802, showing the handrails and stanchions are completely yellow on Cotton Belt's GP20's. Below that is a photo of SP 7206, depicting the Phase II frame difference. The article also includes excellent HO scale plans.
The only plastic HO scale GP20 offered until P2k's has been Tyco/Mantua's 1960's tooling, which left a great deal to be desired. Despite only 260 units built, GP20's were landmark diesels insofar as they heralded the turbocharged age for EMD locomotives (the SD24 notwithstanding), and helped usher in the second generation.
© Rob Sarberenyi
Modeling choices at the moment are:
Lionel information kindly supplied by Britt Johnson
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This document prepared and maintained by Richard.A.Percy.
All Corrections, Additions and Flames should be aimed at Richard Percy email@example.com
This document © 1995, 1996, 1997, 1998, 1999, 2000, 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009, 2010. Richard.A.Percy