Atchison, Topeka & Santa Fe 2-10-4 "Texas" Locomotives in the USA

Class 3829 (Locobase 8282)

Data from AT&SF 9 -1920 and 6 - 1927 locomotive diagrams supplied in May 2005 and August 2013, respectively, by Allen Stanley from his extensive Rail Data Exchange. All of Drawing Room Specification Book Number 61 of the DeGolyer Library's Baldwin collection is devoted to Santa Fe locomotive orders in the late 19teens and 1920s. The 3829's specs run from page 339 to 366. (Thanks to Chris Hohl for his 13 December 2020 email noting a key typographical error, and for pointing me to the 1927 set of diagrams that show later changes in this unique engine. Hohl also noted the difference in engine wheelbase measurements described below.) Works number was 52237 in August 1919.

This was a premature Texas arrangement, although clearly it was meant to solve the same problem. In fact, this engine was the first 2-10-4 that trailed a separate tender. When the 3829 was converted to oil-burning in the late 1930s, Chris Hohl noted, its tender held 7.234 US gallons (27,381 litres) of oil. Together with the 15,000 gallons of water, the new tender's weight rose to 375,700 lb.(170,415 kg) and extended the engine and tender wheelbase to 94 ft 1/2" (28.66 m).

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 (5,670 kg). This redistribution 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 four fewer flues than the Santa Fes. Chris Hohl noted that boiler pressure setting increased from the original 195 psi (13.4 bar) to 215 psi by 1927.

A roomy firebox's heating surface area included a combustion chamber and 37 sq ft (3.44 sq m) from four "fire brick" (i.e. arch) tubes.(Baldwin's estimate of 112 sq ft (10.41 sq m) in combustion chamber area seems high given the relatively short extension shown in the diagrams.) In addition to supplying more direct heating surface area, the combustion chamber allowed the tube and flue lengths to be limited to 21 feet each. 15" (381 mm) piston valves supplied steam to the cylinders. Elesco's open-type feed water heater appeared later.

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. The 1927 diagram contains a contradiction on engine wheelbase. The diagram give the 43 ft 10 in shown in Locobase's specs, but the table shows 45 ft 1 1/2" (13.75 sq m).

This was the Santa Fe's only 2-10-4 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 meantime.

Class 5000 (Locobase 457)

Data from 1930 Locomotive Cyclopedia and from diagram hosted on [], accessed 11 March 2007. See also extended set of specifications at DeGolyer, Volume 82, pp. 358+; and "Santa Fe Locomotive 5000 Tested", Railway Age, Volume 91, No22 (28 November 1931), pp. 829-832 (Thanks to Chris Hohl for his 2 July 2015 email pointing out the tender's original capacity.) Works number was 61524 in October 1930.

The original Baldwin specs show that three thermic syphons added 127 sq ft (11.8 sq m) to the firebox heating surface, which also comprised 130 sq ft (12.08 sq m) in combustion chamber and 22 sq ft (2.04 sq m) in two fire brick tubes. The firebox crown sheet and side sheet and the combustion chamber were made in one piece. Elesco supplied the K 50 E feed water heater. Later diagrams show that the fire brick tubes had been removed; superheat was then calculated at 2,550 sq ft (236.9 sq m). Piston valves measured 15" (381 mm) in diameter

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 dimensions for the Santa Fe's fleet of Texas engines: 5001-5010 (Locobase 458), and 5011-5035 (Locobase 91).

The Baldwin specs show that the adhesion weight forecasts fell short. Maximum axle load was supposed be 72,150 lb (32,727 kg) and total weight on the drivers should come to 349,910 lb (158,717 kg). Apparently the railroad recognized the difficulties inherent in predicting weights for such a new design as they did not refuse the engine as the specs suggested they should:"Locos. will not be accepted by Ry co if weight per axle varies more than 500 pounds above or below that specified."

Chris Hohl pointed out that this first locomotive came to the railroad trailing a tender with a 27-ton (24,494 kg) capacity.

Also found in the specs is a detailed justification by General Steel Castings Corp. for the cast-steel bed with cylinders cast integrally. "On the basis of the above locomotive bed with integral cylinder weights a saving of 4,550 pounds is indicated over the separate cylinder design." GSCC was established by Baldwin at its Eddystone Plant in 1928.

See Locobase 8282 for the earlier 3829, a 1919 singleton derived from the 3800 class of 2-10-2s, but fitted with a two-axle trailing truck. The Madame Queen's tests in July and August 1930 took the engine over the Pecos Division between Clovis and Belen, NM. The Santa Fe reported that when compared to the 3800 class 2-10-2s, the 5000 would handle "approximately 15% more toonage in 9% less time and with 17% less coal per 1,000 gross ton miles."

The design's impact on operations was assessed as follows: "The resultant marked reduction in train-hours per ton handled, tendency to eliminate overtime, and minimizing labor and fuel costs due to delays will have a highly favorable effect upon operating expenses." A key additional benefit: "in addition, the important objective will be achieved of giving better service to shippers.

Class 5001 (Locobase 458)

Data from tables in 1947 Locomotive Cyclopedia, supplemented by Alfred W Bruce, The Steam Locomotive in America - Its development in the twentieth century (New York: W W Norton, 1952), p 311; " and "New Steam Locomotives for the Santa Fe", Baldwin Locomotives Magazine, Volume 17, No 1 (July 1938), pp. 14-15. See also "Atchison, Topeka and Santa Fe steam engine diagrams and blueprints," Kansas Memory, a website of the Kansas Historical Society, diagram at [] . (Thanks to Chris Hohl for his 24 October 2015 email pointing out the oil-burners' tender data.) Works numbers were 62153-62162 in 1938.

Madame Queen", (# 5000), was a single locomotive produced in 1930 with 69" drivers; see Locobase 457. In 1938, ten more --five coal (5001-5005), five oil-burning (5006-5010) -- were produced with 74" drivers and larger boilers; these are described in this entry.

Firebox heating surface included 168 sq ft (15.6 sq m) from three thermic syphons and arch tubes. The class also had Worthington Type 6-SA feed water heaters and an American multiple throttle. (A 1929 committee summary of locomotive appliances noted that the multiple throttle placed in the smokebox made the best use of the superheated steam to supply auxiliaries while reducing slipping. Such an installation had also eliminated superheater dampers.)

A one-piece bed formed the backbone with cylinders (including the back cylinder heads) cast integral. Shipping weight for this component came to 87,128 lb (39,521 kg).

The oil-burners' tenders carried 20,000 US gallons (75,700 litres) and 7,000 gallons (26,495 litres) of fuel oil; empty weight was 171,800 lb (77,927 kg) and weight fully loaded reached 394,600 lb (178,987 kg). They rolled on either two six-wheel trucks; each Buckeye truck's wheel base was 100"(2.54 m), the Pullman trucks stretched to 150" (3.81 m) each.

Finally, the last 25 (5011-5035) were built during WW II with roller bearings and the 16-wheel tenders (See Locobase 91).

Cylinder HP was over 6,000 hp. The tall drivers were unusual for so large a freight engine.

Bruce observed that these locomotives developed probably the highest piston thrust ever recorded -- 219,000 lb (99,337 kg) . To absorb such loads, the driving axles measured 15" (381 mm) in diameter and the frames were 7" (178 mm) deep. This class was later refitted with 105 sq ft (9.75 sq m) of security circulators in place of the thermic syphons; total firebox heating surface decreased to 569 sq ft (52.85 sq m).

Class 5011 (Locobase 91)

Data from tables and diagrams in 1947 Locomotive Cyclopedia. See also "Atchison, Topeka and Santa Fe steam engine diagrams and blueprints," Kansas Memory, a website of the Kansas Historical Society, diagram at []; and "New Locomotives on the Santa Fe", Baldwin Locomotive Magazine, Volume 1, No 3 ( Third Quarter, 1944), pp. 24-25. (Many thanks to Chris Hohl for his 22 September 2017 email reporting unlikely boiler pressure values for 177 entries. A Locobase macro caused the error .Hohl's 9 January 2022 email noted slight differences in engine weight, maximum axle loading, wheel bases, tube length, and superheater area) Baldwin works numbers were 70817-70841 in 1944.

These were the last twenty five 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).

Thermic syphons contributed 30 sq ft (2.78 sq m) to firebox heating surface. (Locobase is puzzled by the much smaller area shown for this class compared to earlier Santa Fe 2-10-4s. He wonders if the smaller firebox reflected a scarcity of the metals that would have been used to construct them.) Piston valves measured 15 inches (381 mm) in diameter.

As delivered, the 5011's loaded tender weight came to 369,690 lb (167,689 kg). Even then, they were credited with almost exactly the same capacities as later tenders shown in the specifications.

Their capabilities were prodigious, a combination of speed and hauling ability that underscored the "superpower" ideal. Baldwin's house organ described some feats by the class leader in late 1944. 5011 took on Cordy Hill, a five-mile stretch on the Missouri Division (Argentine, Kan and Shopton, Ia). Ruling grade of 0.8% and the locomotive entered the list pulling 5,441 tons of train in 94 cars at 56 mph (90 kph) and summited the grade at 18 mph (29 kph). On another 0.8% that ran for only two miles, 5011 hauled 121 cars beginning at 52 mph and dropping no lower than 40 mph.

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 firebox as had these Texas engines was only just big enough to service the immense boilers.

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. As with the earlier Texas engines, this class had Worthington 6-SA feed water heaters and American multiple throttles.