Southern Pacific class AC-7

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Southern Pacific class AC-7
Power type Steam
Builder Baldwin Locomotive Works
Serial number 61952-61963, 62038-62051
Build date January-August 1937
Configuration 4-8-8-2
Gauge ft 8½ in (1435 mm)
Driver size 63 in diameter
Weight on drivers 514,800 lb
Total weight 639,800 lb
Boiler pressure 250 psi
Feedwater heater 6SA Worthington
Cylinder size 24 in dia × 32 in stroke
Tractive effort 124,300 lbf
Career Southern Pacific Railroad
Class AC-7
Number in class 26
Number 4151 – 4176
First run February 8, 1937
Retired 1954 – 1958
Disposition scrapped

Southern Pacific Railroad's AC-7 class of cab forward steam locomotives was the fourth class of the 4-8-8-2 locomotives purchased by Southern Pacific (SP). The locomotives were built by Baldwin Locomotive Works and shared many of the same characteristics of previous AC class locomotives.

The AC-7s were only slightly larger than their AC-6 predecessors, but they included larger tenders and a beveled cab front in contrast to the earlier classes' flat cab front. In the early 1940s, the majority of the class received larger cab windows of a design that would become standard with the AC-8 class.

In April 1937, locomotive number 4162 was pulled aside for a series of publicity photos at SP's Sacramento, California, shops. It was posed alongside the railroad's first locomotive, C. P. Huntington a diminutive 4-2-4T, especially when compared to 4162.

The AC-7 class locomotives were all removed from active service between 1954 and 1958, and they were all scrapped shortly after their removal from service. The first to be scrapped was 4155 on November 26, 1954, while the last was 4172 on April 24, 1959.

[edit] 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)