By the mid-1900s, the Norfolk and Western Railway (N&W) primarily relied on 2-8-0 "Consolidation" type locomotives to pull the company's heavy freight trains.

375-449) were delivered from the American Locomotive Company's (ALCO) Richmond, Virginia works from June 1906 to February 1907, and 50 (Nos.

[1] The M class would prove to be a mainstay of N&W motive power, working in mainline, transfer, switching, and branch line service.

Popular in service, crews would come to affectionately nickname the locomotives “Mollies,” a moniker which stuck until their retirement in the late 1950s.

Though utilizing a larger boiler than either the Ms or M1s, the M2s possessed a relatively small heating surface area in the firebox, resulting in considerable difficulty in maintaining steam.

In spite of the issues (along with subsequent unsuccessful modifications), the M2s lasted in service for considerably longer than the M1s, being among the few larger examples of non-articulated freight power owned by the N&W.

After World War II, however, the N&W began exploring potential replacements, as many of the M’s had begun to show their age; the locomotives also failed to meet smoke abatement laws in many of the cities along the N&W network.

Induced draft fans, driven by steam turbines, were installed, along with mechanical stokers and water level controls; these were added so the locomotives could be left alone for long periods of time and gave rise to the nickname "Automatic Switcher”.

Both locomotives were also fitted out with mechanical lubrication and modified tenders, providing an increase in water and coal capacity.

The issues encountered in the experiment and the advent of more modern motive power in the form of 0-8-0 switchers (both acquired secondhand from the Chesapeake and Ohio Railway and built in the N&W’s own Roanoke Shops) did little to prolong the service lives of the already subpar M2’s.