Help the old steam guy out here, folks. The Kalmbach special "Diesel Victory" has a lot of stuff about how diesels displaced steam, and some comments about EMD's switchers. Now I can understand that SW meant "SWitcher", but then they came up with NW models. Northwest?? And why the myriad of dash numbers. Did each one mean an increase in HP? Is there a logical explanation to all of this? Why is an SW-2 not an NW-whatever?
NW means Nine hundred horsepower; Welded frame. SW means six hundred horsepower; welded frame. I guess the SW stayed with the series. This is discussed in the kalmbach Model Railroader Locomotive Cyclopedia, Vol 2. Diesel Locomotives, page 34. [ November 29, 2005, 06:47 PM: Message edited by: sapacif ]
Still, I assure you the nomenclature is correct. How about the SW1? Was it Six hundred horsepower? It's just those marketing guys! What do they know? This information is on page 34 of the Model Railroader Cyclopedia Vol. 2; Diesel Locomotives. There was also an SC model comparable to the SW1. The "C" stood for the cast frame. The SWs have a fillet in the ends of the frame and fill in there at about a 45 degree angle. The SCs do not have that. In the SC list, I see a Boston and Maine #1103, made in 1936. As I am looking at them here, the SC and SW models look pretty much alike. It looks like the early engines were numbered for models, ie, 1,2,3,etc. later on, the number stood for the horsepower, ie, SW600, SW900, SW8. Also, "The SW and SC models were manufactured from 1936 to 1938." That seems a lot older than the engines I refer to as SW, so I am pretty sure the nomenclature just stayed with the switcher engines. More info: http://www.alaskarails.org/terminology/loco-terms.html http://www.trains.com/Content/Dynamic/Articles/000/000/003/078yguuo.asp [ November 29, 2005, 07:35 PM: Message edited by: sapacif ]
Because originally there were two models, the SW and NW. The "NW2" would be the slightly higher horsepower, improved version of the original. Besides, who sez model designations have to make sense?
According to the Sources I have the SW1 was produced starting in 39,same with the NW2, but that has to just be the EMD version not the EMC version.
The reason behind offering the same switcher with either a cast frame or a welded frame was due to some railroads not trusting the welding technology, electric welding being in it's infancy at the time. NW-2's actually had welded frames, with what have become refered to as "falsies" welded on the frames next to the step wells to give the impression of cast frames The reason for the "NW" instead of "TW" as a model designation is due to the prime mover originally developing 900 hp, and then being raised to 1000 hp. EMD originally started out designating new models by horsepower SW= 600hp, NW= 1000hp), then by production sequence (SW-7, 8, 9), and then returned to horsepower, SW1200, 1500, ect. Tom
