SP Pages

4-6-6-2's on
"The Altamont"

Photograph by (as it turns out) the late Fred Stoes; a small version of this photo appears in John Signor's Signature Press book Southern Pacific's Western Division.

1937 Altamont Pass & Vicinity Map
(opens in new window)

According to Guy Dunscomb's book, A Century of Southern Pacific Steam Locomotives, SP's AM-2's led a rather checkered life, starting out as compound 2-6-6-2 Class MM-2's 4200-4211. Unfortunately, one of the class's lead truck derailed, putting a passeneger train into the ditch. Thus, in quick succession, they were modified with four-wheel lead trucks; demoted to freight service; and set aside by the mid-1920's. Just before the Depression, three were simpled and reclassed as AM-2. The rest languished in Dunsmuir and Sacramento dead lines until the economy picked-up in 1935-36, when they too were simpled and returned to service. In 1938, SP renumbered them as 3900-3911 to make numerical room for more 4-8-8-2's.

What Dunscomb didn't mention was that many (all?) of the AM-2's were Western Division engines until about the outbreak of WWII, when SP assigned the class to the Portland Division, where they roamed the main to Eugene, and the Siskiyou Branch as far as Ashland.

I found the above photo at the bottom of an untouched-for-25-years file drawer, and as it turns out after some discussion at Yahoo's Espee Group, the shot was the work of the late Fred Stoes, although I don't think that Fred gave it to me.

Said photo records eastbound 3901 and 3907 on train 406 approaching Altamont station not too far behind Fred's back. Train 406 was a second class manifest sheduled (in 1937) to run from Newark to Tracy in a rather zippy 2'10". Given the Dunscomb info, the picture dates to the 1938 - 41 era.

"SP rated the 3900's at 4150 "M's", units of 1000 pounds, eastbound over The Altamont" (Altamont Pass), so the pictured doubleheader was good for 4150 tons. You can check for yourself in the 1937 timetable's Rating of Locomotives - Western Division chart (opens in a new window). Interestingly, Western Division Timetable 243 of July 6, 1947 allows the AM-2's a derated 3700 tons, purely academic, since the engines never returned to "The Western" and were all gone by September, 1948, when obsolescense finally caught up with the last of the bunch - the road (second) engine in the above photo.

An aside: The 1937 TT does not give ratings for E-23 4-4-0's, but the 1947, the 1500 & 1502 did appear in the chart. In 1947, the E-23's were good for 525 tons eastbound and 500 tons the other way. I doubt that they strayed that far from the Oakdale and other San Joaquin Valley branches, though.