SP's Sacramento Locomotive Rebuild Programs

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This page was last updated on September 25, 2015.

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Between 1970 and 1989, Southern Pacific rebuilt and upgraded hundreds of locomotives at its Sacramento, California, general shops. The railroad started its locomotive rebuild program in 1970, at almost the exact same time as AT&SF's famous Cleburne F7 (CF7) program. Most of the rebuild effort took place at Sacramento, but some work was completed at Houston, Texas.

Southern Pacific rebuilt diesel units under three different programs:

'E' or 'R'

In January 1977, SP made the change from 'E' suffix, to 'R' suffix as part of the locomotive classification, when Southern Pacific Equipment Company was merged with the railroad. SP only used the 'E' or 'R' suffix as part of its locomotive classification, and did *not* use 'E' or 'R' as part of of the locomotive model.

The 'E' and 'R' suffix is used here to be consistent with previous railfan publications.

Although Southern Pacific preferred the term "upgraded" and did not use the terms "rebuild" or "rebuilt," both terms are used here because throughout the industry, the effort to upgrade a locomotive is much less than what SP did. And the so-called upgrade program used by SP included removal of all components, stripping to the frame, and re-installation of up-to-date wiring and modern components as well as complete modernization of of the carbodies themselves.

Joe Strapac wrote to the Espee List on May 18, 2013:

In 1970, SP pulled a surprise and began upgrading diesels, beginning with older GP9 and SD9 units. They emerged from the shop virtually unchanged in primary features and were given new numbers in the order of their release dates. SP assigned new class designations (in internal publications and stenciled inside the cab) with the "E" suffix. This was accounting shorthand for the fact that the locomotives had been sold to subsidiary Southern Pacific Equipment Company and leased back. All SP rosters of the time showed these classes as locomotives emerged. Your humble servant, at that time not that well in touch with the nationwide diesel fan movement (there were about five of us...) applied the label "GP9E" and "SD9E" in the old Southern Pacific Motive Power Annuals.

Fast forward a few years. SP decided to merge the SP Equipment Company into the parent SP and eliminate the leaseback accounting, but continue the physical upgrading. A new internal label was coined: "General Repair and Improvement Program," or GRIP. Memos were issued and new class designations for subsequently released units carried the suffix "R." The old "E" suffix continued to be used on older upgraded units.

At the same time, the general consensus among the growing body of diesel locomotive historians was that a generic "R" should be applied to everyone's rebuilt/upgraded locomotives. That suffix has become prevalent and I adopted it (those guys ganged up on me...) I may point out that the "E" was still in use on 1970s-era upgrade class designations for years after the "R" came into use.

So both are good (as far as I understand it), depending upon the era and the particular locomotive in question.

R8 Program

All units in the R8 program were recapitalized by selling them to its Southern Pacific Equipment Co. subsidiary, which paid for the actual rebuild work, then leased the units back to SP. Units completed under the R8 program were designated by an E suffix to the railroad's model classification designation, such as EF418E for GP9s, EF618E for SD9s, and EF420E for GP20s, etc. The E suffix denoted ownership by "SPE Co."

Although the rebuilt units were never officially designated as such, except for some documents that used an "R8-SPE Units" designation, the railfan community soon placed its own name on the rebuilt units. As early as April 1970, reports in the railfan press began using the E suffix to designate the rebuilt units, using GP9E for the GP9s, SD9E for the SD9s, and GP20E for the GP20 units.

"They emerged from the shop virtually unchanged in primary features and were given new numbers in the order of their release dates. SP assigned new class designations (in internal publications and stenciled inside the cab) with the 'E' suffix. This was accounting shorthand for the fact that the locomotives had been sold to subsidiary Southern Pacific Equipment Company and leased back. All SP rosters of the time showed these classes as locomotives emerged." (Joe Strapac, email to Espee discussion group, May 18, 2013)

The use of the E suffix on the locomotive model designation for rebuilt units soon became so embedded among railfans that today most will argue strongly that it was an official railroad designation, which in fact, it never was. To the railroad, the fact that the rebuilt units received new road numbers was sufficient to show the newly rebuilt status for each class of locomotives. It should be noted here that throughout the regular publication of the company's semi-annual Locomotive Data Book, up to and including the final issue in February 1996, Southern Pacific continued to use only the original model designation, i.e., GP9 and SD9, for both rebuilt units, and for non-rebuilt units. The E suffix was only used as part of the official locomotive classification system. However, in the interest of clarity and simplicity, this article will use the E suffix for rebuilt units.

First examples include SP GP9E number 3300 and SD9E number 4300. SP 3300 was rebuilt from GP9 3434 and completed in February 1970 (renumbered to SP 2886 in 1978); and SP 4300 was rebuilt from SD9 3810 and completed in August 1970. In SP's unique locomotive classification system, they were EF418E, for a GP9E, and EF618E, for an SD9E. Several GP20s were also rebuilt to GP20E, using the EF420E for their classification.

Included in the R8 program, between March 1971 and June 1974, were units rebuilt by SP's Houston General Shops. A total of 71 switchers were rebuilt in Houston, including three SW7Es, nine SW9Es, 10 SW900Es, 11 SW1200Es, and 38 NW2Es.

From R8 to GRIP

The break between the use of the E suffix (R8 program) and the R suffix (GRIP) took place in January 1977, when Southern Pacific Equipment Co., was merged into Southern Pacific Transportation Co. To show this change in ownership, the suffix portion of SP's locomotive classification system was changed. Examples include (for the SD9s): EF618-E1 and EF618-E2 becoming EF618-R1 and EF618-R2. At the end of 1976, the tax advantages of SP selling the units to SP Equipment Co., then leasing them back, apparently went away. From 1977 on, SP was able to retain full ownership and still claim new-unit status for its rebuilt locomotives because, as a source at SP has said, the rebuild effort was costing more than 50 percent of the cost of a new locomotive. This allowed the railroad (instead of its equipment subsidiary) to recapitalize the rebuilt locomotives and begin depreciating their value again. The GRIP rebuild program was introduced by way of a letter dated December 6, 1976 from SP's Chief Mechanical Officer, at which time the change to the new suffix, from E to R, was also laid out as to how the locomotive classifications would also be changed.

Some units were rebuilt under both the R8 program (1970-1976) and under GRIP (1977-1980). Examples would be SP 3843, a GP9E completed in December 1976, and SP 3844, a GP9R completed in January 1977. There were other examples of models that crossed over the date of change, including SD9s (SD9E and SD9R), SD35s (SD35E and SD35R), and GP20s (GP20E and GP20R). These were the only models that were rebuilt under both programs. There were no SD7Es or GP35Es. Also, the SD40R and SD45R rebuild program was done after 1977, so there were no SD40Es, or SD45Es.

Confusion between which suffix to use, E or R, was added in 1981 with the publication of the "1981 SP Review," which showed the rebuilt SD7s model SD7E and as class EF615-R1. Because they were completed under GRIP in March 1979 to June 1980 as SP 1500-1542, these 43 units should all be referred to as SD7Rs.


Under the General Rehabilitation and Improvement Program (GRIP), after 1977, SP retained ownership for all of the rebuilt units. These units were designated by adding an R suffix to the model designation, such as SD7R and GP35R. Just one GP35R was completed by SP at Sacramento. The other 60 GP35Rs were completed by Morrison Knudsen (34 units) and Canadian National (26 units).

While the SD35Es completed under the R8 program retained their original 2500 horsepower turbocharged engines (classed as EF625-E1), the SD35Rs completed under GRIP were rebuilt as 2000 horsepower units (classed as EF620-R1). These units are the only known example of actual external difference between E-suffixed units and R-suffixed units.

Contrary to a rumor within the railfan community, the difference between the units with E suffix, such as EF618-E1 for the SD9Es, and units with the R suffix, such as EF618-R1, for the SD9Rs, is not that the E-suffixed units have EMD's 567 engines and the R-suffixed unit have EMD 645 engines. Confusion comes from the practice of using EMD 645 head-piston-liner assemblies in EMD 567C engines. This was a common action by most of the larger railroads beginning in the mid 1970s to reduce their parts inventory, and is in no way an indication of a unit's horsepower rating.

M-99 Program

The M-99 program was in effect between late 1979 and late 1989, and was used for the SD40Rs and the SD45Rs. All units were done by SP at Sacramento. There were 354 SD45s, numbered as SP 8800-9156, and 89 SD40s, numbered as SP 8400-8488. The newest units were eight years old, and the oldest were at least 13 years old.

The first unit to be completed under the M-99 program was SP SD45R 7400, rebuilt from SD45 8809 and completed in December 1979. After the completion of the first SD45R as SP 7400, the program focused on the SD40 units, with the first, SP SD40R 7300 being rebuilt from SD40 8433 and completed in March 1980. A total of 86 SD40R units were completed between March 1980 and August 1981, and were numbered as SP 7300-7385.

With the completion of the SD40R fleet in August 1981, SP resumed work on their large SD45 fleet. As previously mentioned, SP 7400 was the first, completed in December 1979. The remaining SD45Rs, beginning with SP 7401, were completed between September 1981 to September 1983, numbered as SP 7401-7481. The 7500-class SD45Rs were rebuilt in April 1984 to March 1986 (SP 7500-7566). All SD45Rs were completed with 3200 horsepower to reduce the mechanical stress on the 20-cylinder engine block. A total of 167 SD45R units were completed between December 1979 and March 1986. Most of SP's documents, such as its employee timetables and locomotive data books, refer to these units as SD45-2s, rather than as SD45Rs.

A single unique unit in the M-99 program was SD44R 7399. This was rebuilt from SP SD45 8837, but used a 16-cylinder 3000 horsepower engine, retaining is original SD45 carbody. It was completed in October 1981.

After all of the SD45s were rebuilt to SD45Rs, the road started a program to rebuild its large 247-unit fleet of SD45T-2s, numbered as SP/SSW 9157-9404. The SD45T-2R program (126 units) was completed in April 1986 to December 1989. The first two units were completed in April 1986 during the proposed SP/AT&SF merger, and were numbered as SP 9500 and 9501. These numbers conflicted with a group of Santa Fe engines, and the two units were changed in August 1986 to SP 6767 and 6768. The first four units completed received the proposed SPSF yellow and red paint scheme. The entire fleet of 126 units was numbered as SP 6767-6892.

Many former SP employees regularly refer the earlier GRIP rebuild program as GRIP I, and the later M-99 rebuild program as GRIP II.

3200 HP or 3600 HP

Although all of the initial SD45R rebuilds were completed as 3200 horsepower units, over the following years, several units were in service as 3600 hp units. Sources at UP who were also part of the SP mechanical department have said that this was not a formal program, but rather a result of the railroad having to support two types of 20-cylinder equipped locomotives, the older, unrebuilt units, at 3600 hp, and the newer rebuilt units at 3200 hp. While the railroad tried to keep sufficient spare governors for each type at its several maintenance points, at times a 3200 hp unit needed a new governor, and that particular type of governor was not available, especially at remote locations, so the unit received a 3600 hp governor instead.

This change of horsepower rating is very apparent when the road's locomotive data books are compared. In the January 1986 book, SP 7400-7536 are referred to as 3200 horsepower (EF632-R1), and SP 7537-7557 are shown as 3600 horsepower (EF636-R1). In the August 1989 book, all except SP 7516 are show as EF636-R1 to EF636-R3. SP 7516 is shown as EF632-R1.

The June 1991 locomotive data book only adds to the confusion, with SP 7497, 7500, 7507-7509, 7514-7519, 7522, 7524, 7526, 7528, 7532-7534, and 7542, a total of 18 units, shown as 3200 horsepower. All others are shown as 3600 horsepower. Sources at SP have said that many units were also in service as 3400 horsepower, although the locomotive data books do not reflect this variation. This same June 1991 data book also shows the SD45Rs with classifications from EF636-R1 to EF636-R5.

Locomotive Data Books

Throughout the early years of SP's operation of diesel electric locomotives, the company used what was called "Publication S-4549, Classification of Locomotives." A pocket-sized supplement of this larger publication was produced for the benefit of everyday use by mechanical department employees. The actual title of the supplement changed over the years, from "Diesel Unit Data" as early as March 1957, to "Locomotive Data" in July 1976, to "Locomotive Data Book" in June 1991. Until 1971, this book continued as a pocket-sized supplement of the larger Publication 4549, and provided a unit-by-unit list of every locomotive, showing important details and information for use by the company's employees. It was updated regularly by issuing new pages that could be inserted as needed.

In mid 1971, the format was changed. The larger Publication 4549 was abolished and all locomotive information, albeit greatly edited with less depth of information. The last issue of the unit-by-unit version was dated August 31, 1971. The three previous editions were dated March 31, 1970, September 30, 1970, and March 31, 1971. The last issue of the book came in February 1996, before the September 1996 control of SP by UP (the two roads didn't formally merge until February 1, 1998).

After the change in format in 1971, these locomotive data books continued to be pocket-sized, and became so useful and popular to all employees that the April 1987 issue was published with a full color cover by noted photographer Dick Dorn. The final February 1996 edition included a full color photo by Brian Jennison, showing three of SP's newest General Electric AC units on the cover.

Locomotive Classification

Southern Pacific's locomotive classification system can best be explained by quoting Joe Strapac:

"Southern Pacific had always used a classification system to describe its locomotives in internal documents (that's what those small characters stenciled on cab sides below the locomotive number represent). Up until 1965, the class designation itself told little about the locomotive; a class DF-113 was a T&NO Baldwin and a DF-114 was a Pacific Lines SD7, for example. Beginning in 1965, however, SP implemented a highly descriptive classification system that provided accurate descriptions of each locomotive."

The classification system from 1965 served the railroad right through to its last days in 1996. The following table breaks the system down into its basic elements (using an SSW SD45 as an example):

E F 6 36 B C 01      
| | | | | | |      
| | | | | | |      
| | | | | | > Sequence for units of same classification:
| | | | | |       01, 02, 03, etc. - Sequence of original purchase
| | | | | |       E1, E2, E3, etc. - R8 Program
| | | | | |       K1, K2, K3, etc. - Morrison-Knudson rebuild
| | | | | |       N1, N2, N3, etc. - Canadian National rebuild
| | | | | |       R1, R2, R3, etc. - Rehabilitation (GRIP and M-99)
| | | | | > Ownership, if other than SPT Co.:
| | | | |         (blank) - SP ownership
| | | | |         C - Cotton Belt (SSW)
| | | | |         D - D&RGW
| | | | |         L - Other, leased to SP
| | | | |         W - Other, leased to SSW
| | | | > Special features:
| | | |           (blank) - no special features
| | | |           A - Lead or cab unit
| | | |           B - Booster unit
| | | |           T - Equipped for Tractive Effort Booster Unit (TEBU, slug)
| | | > Horsepower in 100s:
| | |             00 - Not powered (TEBU)
| | |             18 - 1750 hp, 30 - 3000 hp, 36 - 3600 hp, etc.
| | > Number of axles.
| > Service assignment:
|                 F - Freight
|                 P - Passenger
|                 S - Switch
> Builder:
                  A - Alco
                  B - Baldwin
                  E - EMD
                  F - Fairbanks-Morse
                  G - General Electric
                  K - Kraus-Maffei

The December 6, 1976 letter that introduced the GRIP rebuild program also included information about how the locomotive classification would be changed. Quoting the letter:

Previous locomotive rehabilitation programs at Sacramento and Houston are being discontinued as such. Beginning next year selected units will be shopped for a General Rehabilitation and Improvement Program.

Classification of units under the future General Rehabilitation and Improvement Program (GRIP) will be as follows:

  • GP9 SP EF418 R1, 2, 3, 4 or 5
  • GP9 SSW EF418 CR1, 2, 3, 4 or 5
  • SD9 SP EF618 R1
  • GP20 SP EF420 R2
  • GP20 SSW EF420 CR2
  • SD35 SP EF620 R1
  • GP35 SP EF425 R1
  • GP35 SP EF425 CR1

The units will be renumbered in accordance with instructions covering previous programs in order to maintain uniformity.

The 'R' designation indicates that unit received the GRIP and future issues of the Locomotive Data Book will also reflect a new year built for such units, same as was done for units under our previous programs.

Speed Lettering

In response to a question about which SD45T-2 units that went through the GRIP program received "Speed Lettering", Elizabeth Allen wrote:

The first SD45T-2R (SP 9500, then 6767, former 9163) was released from Sacramento April 1986. The last, SSW 6892, former SP 9219, was released December 1989. None were painted in speed lettering by Sacramento Shops. SSW 6888-6892 were interesting in that they received "SSW" lettering on the nose, in the standard SP serifed lettering style. The end of the GRIP program was also the end for the Sacramento Shops, and all work was transferred to Denver. SSW 6892 was the last of the GRIP units. SP would acquire rebuilt units afterwards in the form of the MK rebuilt GP40s and SD40/45s. The first few GP40s received standard lettering. (Elizabeth Allen, Trainorders.com, March 3, 2008)

R8 and GRIP Units, By Road Number and Model

R8 and GRIP, By Model -- SP R8 and GRIP rebuilt units, sorted by road number and model.

R8 and GRIP Units, By Year

R8 and GRIP, By Year -- SP R8 and GRIP rebuilt units, sorted by year rebuilt.

R8 and GRIP Units, By Sequence Completed, First To Last

R8 and GRIP, In Sequence -- SP R8 and GRIP rebuilt units, sorted by sequence completed.

Background Note

During 1997 and 1998, while doing some research in preparation for the first Union Pacific Locomotive Directories, I discovered that there is a lack of cohesive historical narrative on the subject of the Southern Pacific's various locomotive rebuilding programs. The most trusted published sources (Strapac, Bain, Garmany, and Shippen) didn't agree on the finer details, so I talked to former SP mechanical department employees who were with UP at the time, and this article was the result, along with information from both published and email sources.

After the initial publication as a web page in August 2002, this article was edited and updated, then published as an article in SP Trainline, Spring 2007, Issue 91. Included in the Trainline article is a full listing of unit numbers and rebuild dates, and a narrative of SP's Locomotive Data Books.

Letter To The Editor

Following the publication of the article in SP Trainline magazine, the following letter to the editor was received on April 29, 2007:

I was delighted to read Don Strack's lengthy article in Volume 91 entitled "SP Locomotive Rebuild Programs, 1970 -1989". From 1978 to 1985, I served as Chief Mechanical Officer and then Vice President of Maintenance of Southern Pacific. My challenge in 1978 was to substantially increase locomotive availability and reliability to meet the requirements of the traffic demands of the railroad. Don explains the time frames of the various rebuild and recapitalization programs that were undertaken. In addition, I want to laud those men and women of Southern Pacific (and Cotton Belt) who were involved in making these programs a success. By the early 1980's we were achieving 90 percent locomotive availability consistently and failure rates were declining.

Prior to inaugurating GRIP on high horsepower locomotives, we established a maintenance program targeting specific failure modes with high horsepower units. Hollis Henderson, then Assistant Chief Mechanical Officer - Locomotives, led this program in identifying the problems and in getting the maintenance work accomplished. At this time, the late Curt Dieterich joined Southern Pacific. Curt's experience was in aircraft maintenance. He brought systems and procedures to the company that resulted in the creation of efficient and economical maintenance programs for our locomotives and structured rebuilding programs for the SD 40 and SD 45 units. At the same time, the late Jim Allen was appointed to head the Sacramento Locomotive Works. Jim came from General Electric and provided extensive experience in production methods and leadership capability. I found it interesting that Strack discussed the building of electrical cabinets at Sacramento rather than making the purchase from EMD. This program involved the crafts and staff at Sacramento. They setup a production line that made a product that was superior in design, more efficient in operation and more economical than we could obtain from the supplier. These cabinets were of the Dash 2 design and were used in all SD 45 locomotives undergoing rebuild.

One more point to make about the men and women of Southern Pacific who maintained those locomotives. Everyone on the system was made aware of what was happening and their role in the entire process. Their response was wonderful to see. Phil Lively, Assistant Chief Mechanical Officer, set the tone for the locomotive shops around the system to bring a high level of care for all power on the railroad.

Finally, the systems that were used for locomotives were extended to the freight car fleet. Dick Lenz, Assistant Chief Mechanical Officer, guided this program and brought new efficiencies and performance to the rebuild shops and to the numerous repair points on the railroad.

Many thanks, again, to Don Strack for his fine article and kudos to the men and women of Southern Pacific who made it all happen!

Robert Byrne
La Quinta, California


Don Bain, CTC Board, October 1985, pages 24-39 (PDF; 17 pages; 12.3MB)

John Bonds Garmany, Southern Pacific Dieselization, Chapter 15, pages 388-397, Appendix 15

Bill Shippen, Southern Pacific 1995 Motive Power Annual, (Four Ways West Publications, 1995), including the excellent SP roster compiled by Richard Barnes and Tony Johnson.

Joseph Strapac, Southern Pacific Review, 1980, pages 3-17

Joseph Strapac, Southern Pacific Review, 1981, pages 78 and 79

Other sources by way of email correspondence in 1999, 2000, and 2002 include Peter Arnold, Mark Gillings, Brian Jennison, Tony Johnson, Scott Thomas, and Howard Wise. A summary of the R8 program and the locomotive data books came from Joe Strapac in 2003.

More Information

"SP Locomotive Rebuild Programs 1970 - 1989" and "Locomotive Data Books" by Don Strack, in SP Trainline, Spring 2007, Issue 91; these two articles include numerous photographs used to illustrate this important ground-breaking rebuild program.