Southern Pacific class AC-11

Infobox Locomotive
name=Southern Pacific class AC-11
powertype=Steam
railroad=Southern Pacific Railroad
gauge=4 ft 8½ in (1435 mm)
railroadclass=AC-11
driversize=63 in diameter
cylindersize=24 in dia × 32 in stroke
weight=657,900 lb
weightondrivers=531,700 lb
boilerpressure=250 psi
tractiveeffort=124,300 lbf
feedwaterheater=6SA Worthington
roadnumber=4245 – 4274
builder=Baldwin Locomotive Works
serialnumber=64677 – 64706
builddate=November 1942 – April 1943
firstrundate=November 24 1942
retiredate=1954 – 1958
disposition=scrapped
whytetype=4-8-8-2

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caption=SP 4274 leading an excursion train out of Reno, Nevada, on December 1 1957.

Southern Pacific Railroad's AC-11 class of cab forward steam locomotives was the seventh class of 4-8-8-2 locomotives ordered by Southern Pacific (SP) from Baldwin Locomotive Works; SP was so pleased with the AC-10 class built a year earlier that the railroad began placing orders for AC-11s while the AC-10s were still being built and delivered. They were built between November 1942 and April 1943, closely resembling the AC-10s.

The first AC-11, number 4245, entered service on November 24 1942, and the last, 4274, on May 9 1943. SP used these locomotives for between 12 and 15 years, with the last retirements from this class occurring on September 24 1958. Shortly after their retirement, the AC-11s were scrapped, with the last, number 4262, on August 27 1959.

References

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