Southern Pacific class AC-6

From TrainSpottingWorld, for Rail fans everywhere
Southern Pacific class AC-6
Power type Steam
BuilderBaldwin Locomotive Works
Serial number61353, 61354, 61382-61389, 61416, 61426-61429, 61491-61494, 61535-61538, 61543, 61544
Build dateMay-December 1930
Configuration4-8-8-2
Gaugeft 8½ in (1435 mm)
Driver size63 in diameter
Weight on drivers517,000 lb
Total weight639,500 lb
Boiler pressure250 psi
Feedwater heater6S Worthington
Cylinder size24 in dia × 34 in stroke
Tractive effort124,300 lbf
CareerSouthern Pacific Railroad
ClassAC-6
Number in class25
Number4126 – 4150
First runJuly 10 1930
Retired19531955
Dispositionscrapped

Southern Pacific Railroad's AC-6 class of steam locomotives was the third of the railroad's classes built with a 4-8-8-2 wheel arrangement. Like the earlier AC-4 and AC-5 classes, the AC-6 class were cab forward locomotives. The AC-6 was slightly larger than the previous classes with a higher boiler pressure and tractive effort rating.

In 1947 and 1948 this class was rebuilt with cast steel frames, increasing the overall weight to 648,000 lb (with 523,600 lb on the drivers). At this time most of the locomotives in the class were also equipped with larger cab windows that became standard for SP's cab forward locomotives beginning with the AC-8 class.

This class was removed from active service between 1954 and 1955 and they were all scraped by March 1956.

References

  • Diebert, Timothy S. and Strapac, Joseph A. (1987). Southern Pacific Company Steam Locomotive Conpendium. Shade Tree Books. ISBN 0-930742-12-5. 
Cab forward steam locomotives of Southern Pacific Railroad
2-6-6-2: MM-2 (rebuilt as 4-6-6-2)
2-8-8-2: MC-1 · MC-2 · AC-1 · MC-4 · AC-2 · MC-6 · AC-3
4-8-8-2: AC-4 · AC-5 · AC-6 · AC-7 · AC-8 · AC-10 · AC-11 · AC-12
Preserved: SP 4294 (AC-12)