Among the first of the Atchison, Topeka & Santa Fe Mikados, these were free-steamers by the looks of the numbers. In terms of weight, the Santa Fe engines were about at the median for US 2-8-2s of the pre-USRA era. Part of the firebox heating surface included 4 arch tubes comprising 25.4 sq ft.
Data also from AT&SF 7 -1920 locomotive diagrams supplied in May 2005 by Allen Stanley from his extensive collection. Information about how many, when, and by whom this class was supplied from http://atsf.railfan.net/atsfstea.html (also visited 6 Feb 2006), the Santa Fe All-Time Steam Roster maintained by Evan Werkema.
Similar to the 3100 class that immediately preceded them, these 30 Mikes were delivered with 57" drivers. The 200-psi boiler increased pulling power. Like the 3100s, these engines saw out steam, retiring in 1948-1954.
3160-3187 had Baker gear; 3188-3257 had Walschaerts. As the data shows, these Mikes were considerable larger than the 3129s that immediately preceded them. If, as Drury (1993) notes, the 3129s were akin to the USRA's light Mikados, then these were the Heavies. They came in two subclasses -- the last 30 apparently being strictly coal burners while the first 98 were a mixture of coal- and oil-burning engines.
No matter, the class was big in both senses and performed throughout the system until 1950-1956. Also, the Santa Fe was sufficiently pleased with the design to go back to Baldwin for 101 more after the USRA era ended; see Locobase 2.
Boiler had feedwater heater
Looks to have been based on the USRA Mikado design, but according to Wes Barris --http://www.steamlocomotive.com/mikado/atsf.shtml, accessed 21 June 2006 -- these were repeats of the 1917 3160 class (Locobase 5499). And in fact the design had the same firebox and only minor tweaks to the heating surface, which increased the superheat percentage.
At the same time Baldwin constructed the first-ever 2-10-2s for any railroad (Locobase 463), the builder produced these very similar Vauclain 4-cylinder compound designs, but ones in which the high-pressure cylinders lay inside of the frame and the low-pressure cylinders outside.
Confusion sets in when one looks at the 1901 diagram, which shows this class as 900-914; obviously the 1902 renumbering must have taken care of that and made room for the class 900 Santa Fes. Locobase doesn't know which way the emulation flowed, but notes that these Mikes (which were early examples of that arrangement as well) had more tubes stuffed into the same boiler barrel and consequently more heating surface.
Such a big engine couldn't be left a compound. Moreover, it needed superheat. So some time later the Santa Fe simpled and superheated this class; see Locobase 8250.
Locobase 8249 described the 885s in their saturated, compound-working original state. It wasn't too long before the Santa Fe was simplifying the layout and not too long after that they installed a superheater. It's odd that so packed a boiler would yield 230 small tubes to allow for 40 large ones, but the total loss in heating surface wasn't extreme.
| Specifications | ||||||
|---|---|---|---|---|---|---|
| Class | 3100 | 3129 | 3160 | 4000 | 885 | 885 - superheated |
| Locobase ID | 5442 | 5498 | 5499 | 2 | 8249 | 8250 |
| Railroad | Santa Fe (ATSF) | Santa Fe (ATSF) | Santa Fe (ATSF) | Santa Fe (ATSF) | Santa Fe (ATSF) | Santa Fe (ATSF) |
| Whyte | 2-8-2 | 2-8-2 | 2-8-2 | 2-8-2 | 2-8-2 | 2-8-2 |
| Road Numbers | 3100-3128 | 3129-3158 | 3160-3287 | 4000-4100 | 855-899 | 855-899 |
| Gauge | Std | Std | Std | Std | Std | Std |
| Builder | Baldwin | Baldwin | Baldwin | Baldwin | Burnham, Williams & Co | Santa Fe |
| Year | 1913 | 1916 | 1917 | 1921 | 1902 | 1919 |
| Valve Gear | Walschaert | Baker | Baker or Walschaert | Walschaert | Stephenson | Baker |
| Locomotive Length and Weight | ||||||
| Driver Wheelbase | 16' | 16' | 16.50' | 16.50' | 16' | 16' |
| Engine Wheelbase | 34.08' | 34.08' | 35.08' | 35' | 31.54' | 31.54' |
| Ratio of driving wheelbase to overall engine wheebase | 0.47 | 0.47 | 0.47 | 0.47 | 0.51 | 0.51 |
| Overall Wheelbase (engine & tender) | 66.02' | 69.39' | 79.15' | 79.10' | 59.46' | 62.28' |
| Axle Loading (Maximum Weight per Axle) | 54300 lbs | 57800 lbs | 66500 lbs | 53560 lbs | 59400 lbs | |
| Weight on Drivers | 218900 lbs | 226300 lbs | 259000 lbs | 260200 lbs | 199670 lbs | 213000 lbs |
| Engine Weight | 284100 lbs | 295000 lbs | 348400 lbs | 342000 lbs | 261720 lbs | 271730 lbs |
| Tender Light Weight | 170900 lbs | 221000 lbs | 277200 lbs | 298500 lbs | 136000 lbs | 165800 lbs |
| Total Engine and Tender Weight | 455000 lbs | 516000 lbs | 625600 lbs | 640500 lbs | 397720 lbs | 437530 lbs |
| Tender Water Capacity | 8500 gals | 10000 gals | 15000 gals | 15000 gals | 7000 gals | 8500 gals |
| Tender Fuel Capacity (oil/coal) | 12 tons | 3300 gals | gals | 5000 gals | 11 tons | 13.5 tons |
| Minimum weight per yard of rail on which locomotive could run | 91.21 lb rail | 94.29 lb rail | 107.92 lb rail | 108.42 lb rail | 83.20 lb rail | 88.75 lb rail |
| Geometry Relating to Tractive Effort | ||||||
| Driver Diameter | 57" | 58" | 63" | 63" | 57" | 57" |
| Boiler Pressure | 170 psi | 200 psi | 200 psi | 200 psi | 225 psi | 200 psi |
| Cylinders (dia x stroke) | 25" x 32" | 25" x 32" | 27" x 32" | 27" x 32" | 18" x 32" | 25" x 32" |
| Low Pressure Cylinders (dia x stroke) | " x " | " x " | " x " | " x " | 30" x 32" | " x " |
| Tractive Effort | 50702 lbs | 58621 lbs | 62949 lbs | 62949 lbs | 51158 lbs | 59649 lbs |
| Factor of Adhesion (Weight on Drivers/Tractive Effort) | 4.32 | 3.86 | 4.11 | 4.13 | 3.90 | 3.57 |
| Heating Ability | ||||||
| Firebox Area | 262 sq. ft | 237 sq. ft | 278 sq. ft | 278 sq. ft | 210 sq. ft | 210 sq. ft |
| Grate Area | 58.50 sq. ft | 58.50 sq. ft | 66.80 sq. ft | 66.80 sq. ft | 58.50 sq. ft | 58.50 sq. ft |
| Evaporative Heating Surface | 4111 | 4086 | 4516 | 4553 | 5366 | 3862 |
| Superheating Surface | 880 | 880 | 1084 | 1143 | 850 | |
| Combined Heating Surface | 4991 | 4966 | 5600 | 5696 | 5366 | 4712 |
| Evaporative Heating Surface/Cylinder Volume | 226.12 | 224.75 | 212.96 | 214.71 | 569.35 | 212.43 |
| Computations Relating to Power Output (More Information) | ||||||
| Robert LeMassena's Power Computation | 9945 | 11700 | 13360 | 13360 | 13162.50 | 11700 |
| Same as above plus superheater percentage | 11698.48 | 13773.30 | 15946.11 | 16040.91 | 13162.50 | 13810.57 |
| Same as above but substitute firebox area for grate area | 52393.18 | 55799.52 | 66362.57 | 66757.09 | 47250 | 49576.40 |
| Power L1 | 11850.99 | 14027.44 | 15510.04 | 16072.53 | 5238.44 | 13128.23 |
| Power MT | 477.42 | 546.62 | 528.09 | 544.72 | 231.36 | 543.53 |
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