Class 3829 (Locobase 8282)

Data from AT&SF 9 -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 (accessed 6 Feb 2006), the Santa Fe All-Time Steam Roster maintained by Evan Werkema.

This was a premature Texas arrangement, although clearly it was meant to solve the same problem. Although the firebox dimensions were the same as the 3800 class of 2-10-2s from which this locomotive was extracted, the trailing truck's two axles bore 12,500 more pounds and allowed a somewhat lower axle loading on all of the driven axles. Also the boiler layout changed with this boiler having 20 more small tubes and 4 fewer flues than the Santa Fes. (The locomotive's Commonwealth trailing truck -- fitted after 1925 -- redistributed the weight more in line with the 3800 2-10-2s.) It was never altered to run as a 2-10-2 like her near-sisters.

This was the Santa Fe's only 2-10-2 for 11 years and the next one -- #5000 "Madame Queen" (Locobase 457) -- reflected the "superpower" revolution in large US locomotives that had occurred in the interim.

Class 5000 (Locobase 457)

Data from 1930 Locomotive Cyclopedia and from diagram hosted on http://www.railroadingonline.net/railroads/atsf/drawings/c5000.gif, accessed 11 March 2007.

Three thermic syphons totalling 127 sq ft in firebox

Madame Queen (# 5000), was a single locomotive produced in 1930. This was a path-breaking engine in its combination of high adhesion and relatively tall drivers supporting a very large boiler pressed to an unprecedented degree. Indeed, except for the 69" drivers, which were supplanted by 74" gliders, this design pretty well established the dimension for the Santa Fe's fleet of Texas engines: 5001-5010 (Locobase 458), and 5011-5035 (Locobase 91).

See Locobase 8282 for the earlier 3829, a 1919 singleton derived from the 3800 class of 2-10-2s, but fitted with a 2-axle trailing truck.

Class 5001 (Locobase 458)

Firebox heating surface included 168 sq ft of thermic syphons (3) and arch tubes.

Some confusion about this class but it appears to sort out as follows: Madame Queen", (# 5000), was a single locomotive produced in 1930 with 69" drivers. In 1938, 10 more -- 5 coal, 5 oil-burning -- were produced with 74" drivers and larger boilers. Finally, the last 25 (5011-5035) were built during WW II with roller bearings and the 16-wheel tenders (record 91). Cylinder HP was over 6,000 hp. The tall drivers were unusual for so large a freight engine.

Alfred Bruce (The Steam Locomotive in America, 1950, pp 311) observes that these locomotives developed probably the highest piston thrust ever recorded -- 219,000 lb. To absorb such loads, the driving axles measured 15" (381 mm) in diameter and the frames were 7" (178 mm) deep.

Class 5011 (Locobase 91)

Three thermic syphons measuring 30 sq ft in firebox

These were the last 25 2-10-4s built for the Santa Fe. Built during WW II as oil burners, they represented the peak of rigid-wheelbase freight locomotive design (although their unusually tall drivers allowed their use, quite successfully, in passenger service).

As steam producers, these engines had few peers. Cylinder HP was over 6,000 hp. Regard the high percentage of combined heating surface devoted to superheating and the very large ratio of tube and flue cross-sectional area to grate area. Even as large a grate as had these Texas engines couldn't choke its massive boiler.

Timken roller bearings applied to all axles (including the tender trucks). Worthington 6SA feedwater heater, cast-steel bed with integral cylinders, lightweight rods were among the other features of this awesome locomotive design.