The Milwaukee Road's A2 class comprised 47

compound Compound may refer to: Architecture and built environments * Compound (enclosure), a cluster of buildings having a shared purpose, usually inside a fence or wall ** Compound (fortification), a version of the above fortified with defensive struct ...

steam locomotive A steam locomotive is a locomotive that provides the force to move itself and other vehicles by means of the expansion of steam. It is fuelled by burning combustible material (usually coal, oil or, rarely, wood) to heat water in the locomot ...

s of the 4-4-2 or 'Atlantic' configuration. The

Milwaukee Road The Chicago, Milwaukee, St. Paul and Pacific Railroad (CMStP&P), often referred to as the "Milwaukee Road" , was a Class I railroad that operated in the Midwestern United States, Midwest and Pacific Northwest, Northwest of the United States fr ...

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 The Baldwin Locomotive Works (BLW) was an American manufacturer of railroad locomotives from 1825 to 1951. Originally located in Philadelphia, it moved to nearby Eddystone, Pennsylvania, in the early 20th century. The company was for decades t ...

, and were

Vauclain compound The Vauclain compound was a type of compound steam locomotive that was briefly popular circa 1900. Developed at the Baldwin Locomotive Works, it featured two pistons moving in parallel, driving a common crosshead and controlled by a common valve ...

locomotives with drivers. The third batch (A2-b) of five locomotive was built by the Milwaukee Road in its

Milwaukee, Wisconsin Milwaukee ( ), officially the City of Milwaukee, is both the most populous and most densely populated city in the U.S. state of Wisconsin and the county seat of Milwaukee County, Wisconsin, Milwaukee County. With a population of 577,222 at th ...

shops with drivers. The fourth batch (A2-c) of 12 engines was built by Baldwin as Vauclain compounds with 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 1927–30.

References

*{{Cite journal , last=Edson , first=William D. , title=Milwaukee Road Locomotives , date=Spring 1977 , journal=

Railroad History ''Railroad History'' (initially, ''The Railway & Locomotive Historical Society Bulletin'') is a biannual peer-reviewed academic journal published by the Railway & Locomotive Historical Society since 1921. ''Railroad History'' consists primarily ...

, publisher=Railway and Locomotive Historical Society , location=Boston, Mass. , volume=136 , pages=28–129 , jstor=43523968 A2 Baldwin locomotives 4-4-2 locomotives Vauclain compound locomotives Steam locomotives of the United States Railway locomotives introduced in 1901 Scrapped locomotives