Class 1 - Jacobs-Shupert (Locobase 8537)

Data from reproduction of the Frisco Man newsletter, Vol XI, # 7 (July 1917), pp. 13-16, found on the Frisco Lines history website -- http://198.209.8.207/lochist/frisco/magazines/fm_1917_07/fm_1917_07.pdf, accessed 4 July 2007, as supplemented by SL&SF All Time Loco Diagrams HS Pub supplied in May 2005 by Allen Stanley from his extensive collection.

These Santa Fes were delivered with combustion chambers that, the article noted, permitted an increase in "furnace volume" (firebox volume) while reducing the firetube length. The same 13" piston valves used in the newly minted 1601 Pacifics (Locobase 8535) served the larger cylinders on these 2-10-2s. Several other components were shared by the two classes including the Jacobs-Shupert bolted fireboxes (that leaked, alas), driving-axle journals, the trailing trucks, and identical-width locomotive frames. The front truck was equalized with the first two driving axles while the trailing truck equalized with the last three driving axles.

Almost all were later rebuilt with radial stay boilers and thermic syphons; see Locobase 8547.

Class 1 - radial-stay (Locobase 8547)

Data from SL&SF All Time Loco Diagrams HS Pub supplied in May 2005 by Allen Stanley from his extensive collection.

When the one and only class of Santa Fes was delivered to the St Louis-San Francisco beginning in November 1916 (see Locobase 8537), they were fitted with fireboxes designed by two Frisco engineers - Jacobs & Shupert -- that eliminated staybolts. Although staybolts were a big maintenance headache for all railroads, the J-S alternative didn't prove much more durable. Designed to be extremely rigid, the structures worked themselves loose under the wracks and strains of the forces generated by such big locomotives.

Some time later (Locobase's date is an estimate), all but 4 were rebuilt with radial-stay boilers with more conventional fireboxes. In the new vessels, the shops put 2 Nicholson thermic syphons. Other than the deletion of 8 fire tubes, the rest of the design was left pretty much as is. Over the course of their careers, nine (8, 23,29, 32, 33, 44, 45, 52, 53) were fitted with Walschaert valve gear.

34 were later described as having been rebuilt beginning in 1936 as 4-8-2s, but Jim Quarles in a 1996 article entitled "Those Magnificent, Distinctive, Homebuilt, Frisco Mountains" (published on the web at http://home.mchsi.com/~zquarles/friscomountains.htm, accessed 7 July 2007) argues that about all that was left of the 2-10-2 in the conversion was the original builder's plate. The others were all scrapped between November 1940 and May 1945.