The SP cab forward 4-8-8-2 Class AC-7 was a steam locomotive used in the United States of America during the first half of the 20th century. This was one of many types of massive oil-burning, cab-forward, steam machines, which were produced by Baldwin Locomotive Works for the Southern Pacific mountain service.
In contrast with early cab-forward types, the Class AC-7 locomotives used a simple articulated design, with high pressure to all cylinders. It was built for standard gauge tracks. In 1937, a series of photographic works was done at Eddystone. Despite their efficiency, all cab forward 4-8-8-2 Class AC-7 steam machines were completely removed from service as they were replaced with diesel locomotives.
Specifications
Type: steam engine
Whyte Configuration: 4-8-8-2
Gauge: 1.435 meters (standard)
Weight: 290,200 kg
Cylinder Size: 610 mm x 813 mm (24 in x 32 in)
Boiler Pressure: 250 psi.
Photo of the SP cab forward 4-8-8-2, Class AC-7, No 4153, taken in 1937.
