I was reading a reprint of a 1946 Union Pacific publication that lists every inch of track, road crossing and railroad crossing, every station building, and every crane, outhouse, wye, siding, junction ... you name it, and then all of the engines, cars, and maintenance-of-way equipment. In the locomotive portion, "MacArthur" is listed as a wheel arrangement. What is that? Is it akin to the different names given by some carriers to the 4-8-4 wheel arrangement, which usually was "Northern?" "MacArthur" can't be a Northern, because UP listed that wheel arrangement. - Richard Copeland, Janison, Pa.A
The date of your list is the key. A "MacArthur" was a 2-8-2, usually a "Mikado" but which was renamed by some carriers for Gen. Douglas MacArthur during the World War II era, when anything indicating a Japanese connection was considered not in good taste.
Historically, the new 2-8-2 name never took hold, and they remained "Mikados" or "Mikes" for short. According to Kalmbach's Guide to North American Steam Locomotives
(Kalmbach, 1993) by George Drury, the Mikado name originated in 1897 when Baldwin built some 2-8-2s for the Nippon Railway of Japan. The first true 2-8-2 for U.S. service was built in 1901.
You are right about 4-8-4s. According to Drury, the 4-8-4 type had more U.S. nicknames than any other steam wheel arrangement. Northern Pacific had the first, in 1926, hence the popular label.
Other 4-8-4 names included Golden State or General Service (Southern Pacific); Greenbrier (Chesapeake & Ohio); Dixie (Nashville, Chattanooga & St. Louis); Niagara (New York Central); Pocono (Lackawanna); Potomac (Western Maryland); and Wyoming (Lehigh Valley). - J. David Ingles