| Milwaukee Road class A2 | |
|---|---|
| Power type | Steam |
| Builder | Baldwin Locomotive Works |
| Build date | 1901–1909 |
| Configuration | 4-4-2 |
| UIC classification | 2′B1′ v4 |
| Gauge | 4 ft 8 1⁄2 in (1,435 mm) |
| Driver diameter | 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 size |
15 × 28 in (381 × 711 mm) |
| Low-pressure cylinder size |
25 × 28 in (635 × 711 mm) |
| Tractive effort | 20,420–22,190 lbf (90.83–98.71 kN) |
| Career | Milwaukee Road |
| Class | A2, A2-a, A2-b, A2-c, A2 |
| Number in class | 47 |
| Scrapped | 1927–1930 |
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.
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.