Southern Pacific class AC-1

Southern Pacific class AC-1

Southern Pacific 4002
Type and origin
Power type Steam
Specifications
Gauge 4 ft 8 12 in (1,435 mm)
Driver diameter 57 in
Weight on drivers 440,800 lb
Locomotive weight 481,200 lb
Boiler pressure 210 psi
Feedwater heater 4¼-BL Worthington
Cylinder size 22 in dia × 30 in stroke
Performance figures
Tractive effort 90,940 lbf
Career
Operator(s) Southern Pacific Railroad
Class AC-1
Number in class 15
Number(s) 4000 4010, 4012, 4014 4016
Retired 1947 1948
Disposition scrapped

Southern Pacific Railroad's AC-1 class of cab forward steam locomotives consisted of locomotives rebuilt from MC-1 and MC-2 class locomotives that were originally built by Baldwin Locomotive Works in 1909. The MC-2 class was the first class of locomotives built and delivered to SP as cab forward locomotives. The AC-1 class was the first of the successful AC series of cab forward locomotives that numbered nearly 200 in total on the SP.

Their rebuilds into class AC-1 occurred around 1930; SP used the rebuilt locomotives through the traffic rush of World War II, then removed them from the roster soon after the war. They were all retired from active service by 1949 and were scrapped soon after their retirement. The last locomotive of this class that was scrapped was number 4014 on April 12, 1949.

References