Athearn No. 88679 is an HO scale ready-to-run model of Southern Pacific No. 9951, one of just three General Electric U50 diesel locomotives owned by the railroad. This DCC-ready Athearn release dates from the original HO U50 production around 2010–2011.
The original TrainReference photographs show Southern Pacific No. 9951 in its later black-and-red paint scheme, with the U50’s enormous hood and unusual span-bolster truck arrangement clearly visible.
At a Glance
- Manufacturer: Athearn
- Product line: Ready-to-Run
- Item number: 88679
- Prototype: General Electric U50
- Railroad: Southern Pacific
- Road number: 9951
- Scale: HO
- Control: DCC-ready
- Original release period: 2010–2011
Athearn 88679 Southern Pacific No. 9951
Athearn released Southern Pacific No. 9951 as part of its original HO scale U50 series. The model was cataloged as item 88679 and supplied DCC-ready.
This is distinct from Athearn’s later Genesis U50 releases. Athearn subsequently produced new Genesis models of SP No. 9951 under different item numbers, including versions with modern DCC and sound electronics. Collectors identifying the older model documented here should look for Athearn 88679.
The General Electric U50
General Electric developed the U50 during the early-1960s horsepower race. Instead of using a single prime mover, the locomotive combined two 2,500-horsepower diesel engines on one chassis, producing a total of 5,000 horsepower.
The U50 was an exceptionally large locomotive, approximately 83 feet 6 inches long. Eight powered axles were carried in four two-axle trucks, arranged in pairs beneath span bolsters. The unusual truck arrangement contributed to the locomotive’s distinctive appearance.
Union Pacific was the principal U50 customer, but Southern Pacific also purchased three examples.
Southern Pacific’s Three U50s
Southern Pacific received three U50 locomotives in 1964 for high-horsepower freight service. They were initially numbered 8500 through 8502.
The locomotives went through two renumberings:
- 8500–8502 — original 1964 numbers
- 9550–9552 — assigned in 1965
- 9950–9952 — assigned in 1969
The locomotive represented by the Athearn model therefore began life as SP 8501, became 9551, and finally became 9951.
SP No. 9951 in Service
Southern Pacific initially used its U50s in freight service associated with the Sunset Route between Texas and Southern California. Later in their careers they worked Southern California freight assignments, including transfer service in the Los Angeles area.
No. 9951 remained in service until 1978. None of Southern Pacific’s three U50 locomotives was preserved.
Identifying Athearn No. 88679
The principal identifiers for the TrainReference model are:
- Athearn item: 88679
- Locomotive: GE U50
- Railroad: Southern Pacific
- Road number: 9951
- Scale: HO
- Original product line: Athearn Ready-to-Run
- Electronics: DCC-ready
Do not confuse No. 88679 with Athearn’s newer Genesis models of SP 9951. The later releases use different product numbers and updated electronics and detailing.
Original Photos
The photographs below show Athearn Southern Pacific U50 No. 9951 originally documented for TrainReference.
References and Further Reading
Related Athearn References
Current Athearn U50 Listings
Current eBay listings related to Athearn U50 locomotives are shown below. For the original model documented here, look specifically for Athearn item No. 88679 and Southern Pacific road number 9951.
As an eBay Partner, I may be compensated if you make a purchase.
 Athearn #88679 HO scale “Southern Pacific” U50 Rd #9951 |  Athearn 50' Superior PD Box cars selection new |
Athearn 5011 40’ Box SP
