Greater success than the Santa Fe Class 3000 was the Virginian Class AE, which a few years later was also built exactly ten times. It was about 70,000 pounds heavier and was factory built as a Mallet locomotive. To avoid the problems of an overly long boiler, the boiler was designed with the largest possible diameter and moderate length to get better proportions. With a diameter of almost ten feet, it is considered the widest locomotive boiler of all time. The low-pressure cylinders also set new standards with a diameter of 48 inches and a volume of nearly 58.000 cubic inches each.
At just over 135.000 pounds, the normal starting tractive effort in compound operation already reached a very impressive value. Like many Mallet locomotives, the AE also had a special starting valve that made it possible to direct the live steam into the low-pressure cylinders if the wheels were in an unfavorable position. This resulted in a starting tractive effort of 162.000 pounds using the calculation method used in Anglo-American countries.
Schematic drawing with dimensions
Locomotive Magazine, April 1919
Due to the dimensions of the locomotives, it was necessary to deliver them without a driver's cab and low-pressure cylinders and only to assemble them in the area of operation, where operation of the locomotives without colliding with obstacles on the track was guaranteed. A relatively short variant was selected as the tender so that existing turntables could also be used. Although these locomotives also had to struggle with steam production as the speed increased, they are considered to be more successful than the ATSF 3000. They were mostly used as pusher locomotives for heavy coal trains, which often only moved at around 8 mph at the ramps and did not overload the boiler of the AE. There are also reports of locomotives pulling trains weighing over 17,000 tons alone. They remained in service for almost 30 years and were eventually replaced on the steepest inclines by electric locomotives.