Southern Pacific class GS-6

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Power type Steam
BuilderLima Locomotive Works
Serial number8013 – 8016, 8248 – 8253 (all for SP)
Build dateJuly-August 1943
Gaugeft 8½ in (1435 mm)
Driver size73½ inch diameter
Weight on drivers283,000 lb
Total weight468,400 lb
Boiler pressure260 psi
Cylinder size27 in dia × 30 in stroke
Tractive effort64,600 lbf, 76,050 lbf with booster
CareerSouthern Pacific and Western Pacific
Number in class16
NumberSP 4460 – 4469,
WP 481 – 486
Nicknames"War Babies", "Baby Daylights"
First run1943
Retired1953 (WP), 1958 (SP)
Dispositionmost scrapped, SP 4460 preserved

The GS-6 is a semi-streamlined 4-8-4 Northern type steam locomotive that served the Southern Pacific Railroad from 1943 to 1958 and the Western Pacific Railroad from 1943 to 1953. They were built during World War II for the Southern Pacific Railroad by the Lima Locomotive Works and were numbered 4460 through 4469 for Southern Pacific and 481 through 486 for Western Pacific. GS stands for "Golden State" or "General Service."

In 1943 when the Southern Pacific Railroad placed an order for fourteen new "Daylight" locomotives from Lima, it was World War II and the US government had taken over all locomotive manufacturers. SP's order was turned down, with the government declaring that streamlined passenger engines were not necessary and would not help in moving wartime traffic. Southern Pacific re-designed the engines for general service and it was finally approved, but the government took four of them and gave them to the smaller and power-starved Western Pacific Railroad.

The GS-6 had an appearance similar to the GS-2: They featured a silver smokebox with a cone-shaped single headlight casing and 73 inch drivers. Like all GS engines they had teardrop classification lights, an air horn, and whistles. They retained the skyline casing on the top of the boiler, but they did not retain the side skirting of previous GS locomotives. Southern Pacific's GS-6s also lacked the orange and red "Daylight" paint scheme that the previous GS engines so famously wore. Western Pacific's GS-6s received "elephant ears" similar to that of the Union Pacific Railroad's 4-8-4 locomotives. Like the GS-5, they were also equipped with roller bearings, giving the GS-6 a smoother ride and extra weight, and they also featured all-weather, fully-enclosed cabs.

They were primarily used by the Southern Pacific for the San Joaquin Daylight, as well as San Jose-San Francisco commute trains and freight service.

The Western Pacific used its GS-6s (GS-64s as WP classified them) on various passenger trains and in freight service as well. They acquired a different look from their SP sisters when the WP applied the "elephant ear" style smoke deflectors to all six locomotives. When the Western Pacific dieselized in 1953, they sold several of the GS-64 engines to Southern Pacific to be used as sources for spare parts, but kept three tenders and converted them to steam generators for rotary snowplows.


One GS-6 survives today, Southern Pacific 4460, which pulled the final movement of steam on the Southern Pacific Railroad in 1958. It was donated to the Museum of Transportation in St. Louis, Missouri, where it has remained ever since. Also, the tender of Western Pacific GS-6 484, which was used in its final years as a steam generator for a rotary snowplow, is stored at the Western Pacific Railroad Museum in Portola, California.


  • Diebert, Timothy S. and Strapac, Joseph A. (1987). Southern Pacific Company Steam Locomotive Compendium. Shade Tree Books. ISBN 0-930742-12-5. 

External links

GS-class steam locomotives of Southern Pacific Railroad
Classes: GS-1 · GS-2 · GS-3 · GS-4 · GS-5 · GS-6
Preserved: SP 4449 · SP 4460