Kansas City, Mexico, & Orient / Santa Fe 2-10-0 "Decapod" Locomotives of the USA

Class Details by Steve Llanso of Sweat House Media

Class 801 / 2565 (Locobase 466)

Data for this version originally taken from Santa Fe drawings (aka Kansas City, Mexico, & Orient 801-805) preserved at http://www.railroadingonline.net/railroads/atsf/drawings/index.shtml, last accessed 13 January 2010; that site ceased to exist. Data in the specification shown above from Santa Fe diagram on 186 at Kansas Memories Digital Archives at http://www.kansasmemory.org/item/221763/page/209, dated 15 January 1929, last accessed 8 December 2014 and DeGolyer, Volume 76, pp. 112+. See also E D Worley, Iron Horses of the Santa Fe (Dallas: Southwest Railroad Historical Society, 1976), p. 199. Works numbers were 58571-58575 in July 1925.

Five engines of Baldwin's standard catalog light 2-10-0 developed in the 1920s to put engines with this tractive effort on relatively light rails. E D Worley entered a delightful turn of phrase when he characterized this design as derived from the earlier Decapods meant for Russia, but "a different cup from the same samovar."

Piston valve diameter measured a relatively expansive 14" (356 mm). Superheater area was estimated at 721 sq ft (67 sq m), but was shown as 693 sq ft in 1929. Locobase notes that Baldwin measured the flue length as 17 ft 6 in, an outside length, while the Santa Fe calculated the length between tube sheets an inch shorter.

There was no mention of thermic syphons in the 1925 specs and the firebox's surface area was given as 203 sq ft (18.85 sq m). By the time the Santa Fe prepared a diagram dated 15 January 1929, however, firebox heating surface included 59.5 sq ft (5.5 sq m) in two syphons.

The KCM & O was absorbed by the Santa Fe in 1929.

Retired in 1953-55.

Class 987 (Locobase 5364)

Data from table in June 1906 AERJ. See also DeGolyer, Volume 24, pp. 258+. Works number was 20326 in April 1902.

At the time of its introduction, this four-cylinder tandem compound was the largest locomotive in the world. (The Santa Fe would break its own record within a year.). One 13 1/2" (343 mm) piston valve served both ends of the long cylinder.

987 saw service for less than a decade as a compound; she was simpled in 1911.

The design was then superheated; see Locobase 8259 for the final result.

Class 987 - superheated (Locobase 8259)

Data from AT&SF 9 -1920 locomotive diagrams supplied in May 2005 by Allen Stanley from his extensive Raildata collection. Information about how many, when, and by whom this class was supplied from http://atsf.railfan.net/atsfstea.html (accessed 6 Feb 2006), the Santa Fe All-Time Steam Roster maintained by Evan Werkema.

Locobase 5364 shows this decapod as originally delivered in a Vauclain tandem-compound arrangement. In August 1911, the railroad deleted the HP cylinders and bushed the LP cylinders to created a two-cylinder, simple-expansion layout. A few years later they added a superheater and shortened tubes and flues by several inches.

In this configuration, the 987 persisted in its pusher work until cut up for scrap in August 1933.

Class 988 (Locobase 465)

See also E D Worley, Iron Horses of the Santa Fe (Dallas: Southwest Railroad Historical Society, 1976); and http://atsf.railfan.net/snippets/locomotives.html (visited 23 July 2004), collection of newspaper clippings gathered by Ellington -- author of Steam Locomotives of the Santa Fe, A Former Shopman's Scrapbook --

Four-cylinder tandem compounds. These two were built by Alco-Schenectady after a single example from Baldwin was delivered. Simpled in 1911, retired in 1938.

Ellington quotes from the "TOPEKA STATE JOURNAL 2/24/1902:

New decapod work. One of the Santa Fe's new decapod engines, which are the heaviest engines in the world, made a record haul yesterday, says a Chicago paper. The engine pulled 703 tons up a grade 6 1/2 miles long, 158' to the mile. The track upon which the performance was made is known as the Cajon Pass, just west of the Sierra Nevada mountains. The load is the largest ever hauled by an engine up a 3% grade, but Vice President Kendrick expects to break this record. The management of the company is so pleased with the work of the decapod, that orders have been given for 75 of them at a cost of over $1,500,000 to be delivered by the latter part of August. Report of a test being made with the engines show that the wear upon the track is not so great as it is by many other, lighter engines. This is accounted for by the fact that the decapods have a rigid wheelbase of 20' and five sets of drivers, but while there are 232,000 lbs on the drivers, total, there are only 46,000 lbs. upon each set. This is less than that resting on the drivers of many passenger engines."

Ellington note: Only three of these decapods were ultimately acquired, derailing difficulties when backing, (among other operating problems), signalled the cancellation of the order for 75 additional copies, and served to introduce the following 2-10-2 type wheel arrangement; addition of a final pair of 'trailing' wheels largely solved the backing difficulties."

Class 988 - superheated (Locobase 8264)

Data from AT&SF 9 -1920 locomotive diagrams supplied in May 2005 by Allen Stanley from his extensive Raildata collection. Information about how many, when, and by whom this class was supplied from http://atsf.railfan.net/atsfstea.html (accessed 6 Feb 2006), the Santa Fe All-Time Steam Roster maintained by Evan Werkema.

Locobase 465 describes the delivery of these four-cylinder tandem compounds and notes that procurement of the remainder of a large order was cut off because these decapods derailed easily when backing up.

Even though they were now orphans together with 987 (Locobase 463), the Santa Fe went ahead with simpling and superheating. 989 was simpled in 1911, 988 in 1915. Note that although the railroad dropped the 988-class's boiler pressure considerably when they superheated the boiler (a frequent tradeoff for such conversions), they managed to retain almost all of the combined heating surface area.

In their altered states, this pair carried on until 1938 -- probably going forward most of the time.

Specifications by Steve Llanso of Sweat House Media
Class801 / 2565987987 - superheated988988 - superheated
Locobase ID466 5364 8259 465 8264
RailroadKansas City, Mexico, & Orient (ATSF)Santa Fe (ATSF)Santa Fe (ATSF)Santa Fe (ATSF)Santa Fe (ATSF)
Number in Class51122
Road Numbers801-805/2565-2569940 / 987987988-989988-989
Number Built512
BuilderBaldwinBurnham, Williams & CoSanta FeAlco-SchenectadySanta Fe
Valve GearWalschaertWalschaertWalschaertWalschaertWalschaert
Locomotive Length and Weight
Driver Wheelbase20'20.33'20.33'20'20'
Engine Wheelbase28.90'29.83'29.83'28.92'28.92'
Ratio of driving wheelbase to overall engine wheebase 0.69 0.68 0.68 0.69 0.69
Overall Wheelbase (engine & tender)65.14'59.50'59.50'62'62.10'
Axle Loading (Maximum Weight per Axle)46600 lbs
Weight on Drivers227060 lbs237800 lbs237000 lbs232000 lbs232000 lbs
Engine Weight253730 lbs267800 lbs266500 lbs259800 lbs260000 lbs
Tender Light Weight165690 lbs132000 lbs132000 lbs135000 lbs130000 lbs
Total Engine and Tender Weight419420 lbs399800 lbs398500 lbs394800 lbs390000 lbs
Tender Water Capacity8500 gals8500 gals7000 gals7000 gals7000 gals
Tender Fuel Capacity (oil/coal)3500 gals14 tons11 tons tons11 tons
Minimum weight of rail (calculated)76 lb/yard79 lb/yard79 lb/yard77 lb/yard77 lb/yard
Geometry Relating to Tractive Effort
Driver Diameter57"57"57"57"57"
Boiler Pressure215 psi210 psi190 psi225 psi180 psi
High Pressure Cylinders (dia x stroke)25" x 30"19" x 32"28" x 32"17.5" x 34"26" x 34"
Low Pressure Cylinders (dia x stroke)32" x 32" (2)30" x 34" (2)
Tractive Effort60115 lbs53493 lbs71083 lbs52133 lbs61694 lbs
Factor of Adhesion (Weight on Drivers/Tractive Effort) 3.78 4.45 3.33 4.45 3.76
Heating Ability
Firebox Area298.50 sq. ft234.20 sq. ft234.20 sq. ft205.40 sq. ft206 sq. ft
Grate Area64.70 sq. ft58.50 sq. ft58.50 sq. ft59.50 sq. ft59.50 sq. ft
Evaporative Heating Surface3159 sq. ft5390 sq. ft3888 sq. ft4682 sq. ft3730 sq. ft
Superheating Surface721 sq. ft850 sq. ft854 sq. ft
Combined Heating Surface3880 sq. ft5390 sq. ft4738 sq. ft4682 sq. ft4584 sq. ft
Evaporative Heating Surface/Cylinder Volume185.34513.28170.48494.65178.53
Computations Relating to Power Output (More Information)
Robert LeMassena's Power Computation1391112285111151338810710
Same as above plus superheater percentage1655312285131161338812745
Same as above but substitute firebox area for grate area7637149182525084621544125
Power L113350439410059438710186
Power MT648.10203.68467.85208.44483.97


If you have any railroad data such as diagram books, rail station plans or anything else that you would be willing to share, please contact us.