Milwaukee Road class A2

The Milwaukee Road's A2 class comprised 47 compound steam locomotives of the 4-4-2 or 'Atlantic' configuration. The Milwaukee Road acquired them in five batches.

Milwaukee Road class A2
Type and origin Power type Steam Builder Baldwin Locomotive Works Build date 1901–1909
Specifications Configuration: ​  • Whyte 4-4-2  • UIC 2′B1′ v4 Gauge 4 ft 8+1⁄2 in (1,435 mm) Driver dia. 84–85 in (2,134–2,159 mm) Boiler pressure 200–220 lbf/in2 (1.38–1.52 MPa) Cylinders 4 (Vauclain compound) High-pressure cylinder 15 in × 28 in (381 mm × 711 mm) Low-pressure cylinder 25 in × 28 in (635 mm × 711 mm)
Performance figures Tractive effort 20,420–22,190 lbf (90.83–98.71 kN)
Career Operators Milwaukee Road Class A2, A2-a, A2-b, A2-c, A2 Number in class 47 Scrapped 1927–1930

The first two batches of 9 and 19 locomotives (classes A2 and A2-a) were built by Baldwin Locomotive Works, and were Vauclain compound locomotives with 84 inches (2.13 m) drivers. The third batch (A2-b) of five locomotive was built by the Milwaukee Road in its Milwaukee, Wisconsin shops with 85 inches (2.159 m) drivers. The fourth batch (A2-c) of 12 engines was built by Baldwin as Vauclain compounds with 85 inches (2.159 m) drivers, while the last batch (A2) was for a pair of engines built by Baldwin as balanced compounds. All members of the class were scrapped between 1927 and 1930.