Southern Pacific Class AC-5

The Southern Pacific Railroad's AC-5 Class (meaning Articulated Consolidation) was the second class of cab forward 4-8-8-2 steam locomotives ordered by the Southern Pacific Railroad (SP). 16 of these engines were built by the Baldwin Locomotive Works between July and September 1929. They were numbered 4110-4125 and were placed into active service soon after construction. The AC-5 class was only slightly larger than the previous AC-4 Class.
These oil-fired engines had three ostensible disadvantages—and one big advantage—over conventionally laid-out locomotives. The disadvantages were the crew's vulnerability in a collision, the need to keep a high water level in the long boiler to account for grades, and an occasional back blast from the firebox from flameout and sudden relight caused by the long distance from tender to grate. (The fuel was helped through the lines by an 5-lb overpressure in the cylindrical tender.) The great advantage was the reduction of smoke in the cab when travelling through the miles of tunnels and snow sheds between Roseville, California and Sparks, Nevada.
The class were removed from active service by 1953 and were all scrapped by 1955. None of the members of the AC-5s were preserved.
==Stock list==
Image	Loco No.	Build date(s)	Builder 	Status
 	4110 	1929 	Baldwin Locomotive Works	Scrapped February 3, 1953. The first 4-8-8-2 cab forward locomotive to be scrapped.
 	4111 	1929 	Baldwin Locomotive Works	Scrapped
 	4112 	1929 	Baldwin Locomotive Works	Scrapped
 	4113 	1929 	Baldwin Locomotive Works	Scrapped
 	4114 	1929 	Baldwin Locomotive Works	Scrapped
 	4115 	1929 	Baldwin Locomotive Works	Scrapped
 	4116 	1929 	Baldwin Locomotive Works	Scrapped
 	4117 	1929 	Baldwin Locomotive Works	Scrapped
 	4118 	1929 	Baldwin Locomotive Works	Scrapped
 	4119 	1929 	Baldwin Locomotive Works	Scrapped
 	4120 	1929 	Baldwin Locomotive Works	Scrapped
 	4121 	1929 	Baldwin Locomotive Works	Scrapped
 	4122 	1929 	Baldwin Locomotive Works	Scrapped
 	4123 	1929 	Baldwin Locomotive Works	Scrapped
 	4124 	1929 	Baldwin Locomotive Works	Scrapped
 	4125 	1929 	Baldwin Locomotive Works	Scrapped
== Gallery ==
File:USA 034 Berkeley 3.jpg
File:4125.jpg
File:USA 023 Oakland 2.jpg
Category:Cab forward locomotives
Category:4-8-8-2 locomotives
Category:4-8-8-2 steam locomotives
Category:Scrapped locomotives
Category:Locomotives
Category:Unique locomotives
Category:Built in 1942
Category:Scrapped steam locomotives
Category:Cab forward steam locomotives
Category:Steam locomotives
Category:Tender locomotives
Category:American steam locomotives
Category:American locomotives
Category:Southern Pacific locomotives
Category:Standard gauge locomotives
Category:Standard gauge locomotives of the United States
Category:Baldwin locomotives
Category:Built in 1929
Category:Eight-coupled locomotives
Category:Articulated locomotives
Category:Mallet locomotives
Category:Articulated locomotives