my ESPEE MODELERS ARCHIVE

California's Railroad to the U.S. 1861 - 1996

28 units built

Delivered in two batches of 10 in 1923 and the other 18 in 1924.

Planned for use of passengers trains, they eventually ended up in every kind of service as more powerful engines were bought.

#4300-4310 had 120-C-2 tenders with 4 wheel trucks, in 1924 they received 120-C-3 tenders from 2-10-2's.

The unique 120-C-4 from 2-10-2 #5000 was used behind #4326 briefly from late 1929 to early 1930.

From Arnold Menke: Diebert & Strapac state correctly that many 4-8-2¹s got disc drivers, but most were Universal, not Boxpok. The name Boxpok was a General Steel Castings (Commonwealth) trademark. Universal discs were made by Locomotive Finished Material Co. and had much larger, and fewer holes than GSC's Boxpok¹s. 4326 was the only Mt-1 with Boxpok discs.

The Mt-1's came with type B (flat bottom) Feedwater Heaters. Subsequent Mt classes had type BL (with notch at front corner).

Many Mt¹s eventually received multiple bearing crossheads. Mt-2's, of course, were built with them. Disc main drivers were applied to many of the 4300's; these were mostly Universal discs, but 4326 was fitted with Boxpok discs. The installation of multiple bearing crossheads and disc wheels was not always simultaneous, some engines did not get both, and some got neither (4300, 4307, 4308, 4311, 4318, 4319). Only occasionally were disc drivers and multiple bearing crossheads added when the skyline case was installed. I have listed below known dates for application of this equipment taken from SP's Descriptive Record of Locomotive cards in CSRM. Application of disc main drivers and multiple bearing crossheads sometimes was not recorded on Descriptive Record of Locomotive cards. For these engines photographic evidence must be used. Whenever I have lacked such evidence I have given "no" with a question mark to indicate that verification is needed. First entry after the engine number is the date of application of multiple bearing crossheads. Second entry is date of application of disc main drivers. Except as indicated above, Universal discs were used.

References:

• A Century of SP Steam Locomotives - Guy L. Dunscomb
• SP Co. Steam Locomotive Compendium by Diebert & Strapac
• The 4300 4-8-2's Southern Pacific's Mt- Class Locomotives (Revised Edition) - by Robert J. Church
• Southern Pacific Steam Pictorial Vol.2 by Dunscomb, Dunscomb & Pecotich
• Volume 8 -- Southern Pacific Mountain 4-8-2 Pictorial - by Duane Karam Jr. & Jeff Ainsworth, Monte Vista Publishing