Southern Pacific class GS-4

Southern Pacific GS-4

SP4449, the youngest (and sole-remaining) GS-4 locomotive, standing idle under steam, waiting to start Christmas excursion, December 13, 2005.

Type and origin Power type Steam Builder Lima Locomotive Works Serial number 7798–7817, 7848–7855 Build date April–May 1941, March–April 1942 Total produced 28

Specifications Configuration 4-8-4 UIC class 2′D2′ h2 Gauge 4 ft 8 1⁄2 in (1,435 mm) standard gauge Driver dia. 80 in (2,032 mm) Wheelbase 88.23 ft (26.89 m) Axle load 69,000 lb (31,000 kg; 31 t) Adhesive weight 275,700 lb (125,100 kg; 125.1 t) Loco weight 475,000 lb (215,000 kg; 215 t) Total weight 788,730 lb (357,760 kg; 357.76 t) Fuel type Fuel oil Fuel capacity 6,275 US gal (23,750 l; 5,225 imp gal) Water cap 23,300 US gal (88,000 l; 19,400 imp gal) Firebox:  • Firegrate area 90.4 sq ft (8.40 m2) Boiler pressure 300 psi (2.07 MPa) Heating surface 4,887 sq ft (454.0 m2) Superheater: ​  • Heating area 2,086 sq ft (193.8 m2) Cylinders Two, outside Cylinder size 25 1⁄2 in × 32 in (648 mm × 813 mm) Valve gear Walschaerts Valve type Piston

Performance figures Maximum speed 110 mph (180 km/h) Tractive effort 64,800 lbf (288.24 kN), 78,000 lbf (346.96 kN) with booster

Career Operators Southern Pacific Company Class GS-4 Numbers 4430–4457 Locale California First run April 1941 Retired 1958 Preserved 1 Restored 1976 Disposition #4449 restored, remainder scrapped

The GS-4 is a streamlined 4-8-4 Northern type steam locomotive used on the Southern Pacific Company from 1941 to 1958. They were built by the Lima Locomotive Works and were numbered 4430 through 4457. GS stands for "Golden State" or "General Service."

Unlike the GS-3, the GS-4 had a dual-headlight casing (top headlight was a mars light) on the silver smokebox. Another change was the all-weather cab. It retained the skyline casing atop of the boiler, skirting on the sides, an air horn to supplement the whistle and teardrop classification lights. They carried the orange and red "Daylight" paint scheme.

The GS-4s were passenger engines capable of 110 mph (180 km/h), though timetable speed limit never exceeded 75 mph or 121 km/h. Southern Pacific's premier passenger trains were pulled by GS-4s, the Coast Daylight, San Joaquin Daylight, Lark, Cascade, Golden State and Sunset Limited. During wartime and in the first years after the war some of the GS-4 locomotives were painted black; by 1948 all had been repainted into Daylight colors. Starting in March 1950 most were painted black again and had their side skirts removed for easier maintenance, and were reassigned to the San Jose-San Francisco commuter trains, freight service and the occasional San Joaquin Daylight (steam locomotives remained on that train as late as 1956 which made the San Joaquin Daylight the last streamliner train to be pulled by steam on the Southern Pacific) until new diesels arrived and they were retired. The last GS-4 engines were deskirted and painted black in 1956; a GS-4 pulled its last passenger train in January 1957. All were retired by 1958. GS-4 number 4443 pulled one of the final steam excursions on the Southern Pacific in 1957, and appeared in the opening credits of the Frank Sinatra film Pal Joey.