Class A (Locobase 4790)

Data from Scientific American - New York, May 20, 1905

story on modern high-speed engines.

292 was the single A, Harriman-design Atlantic obtained by the Chicago & Alton after its appearance at the 1904 St Louis Exposition. It quickly left C&A's employ, going into service with the Texas & New Orleans subsidiary of the Southern Pacific, where it joined three other Baldwin-built Atlantics. Drury (1993) describes the sale, but doesn't show the locomotive in his SP rosters.

It's larger than the other Harriman A-3 Atlantics. http://espee.railfan.net/sp_steam_a-03.html notes that this class received 77" drivers later in their careers and all were scrapped in 1937.

Class A-1 (Locobase 8658)

Data from T&NO 3 - 1932 Locomotive Diagrams supplied in May 2005 by Allen Stanley from his extensive collection.

This class went into service as six of the Southern Pacific's 16-locomotive A-1 Vauclain Compound Atlantics; see Locobase 10786.

They were sold to the T & NO. (1 in 1906, 1 in 1908, 2 in 1912, and 1 in 1913). The last of the six suffered a boiler explosion in 1913 and was rebuilt; see Locobase 8659.

In 1925, the T & NO took the quintet (which included 2 then attributed to the Galveston, Harrisburg & San Antonio) and superheated them, completing their transitions to local passenger engines. So modified, they served the T & NO through World War II before heading to the scrapyard in the period between September 1946 and May 1947.

Class A-1 (Locobase 10786)

Data from Baldwin Locomotive Works, Record of Recent Construction ((1903), No. 39, p. 256-257. Works numbers were 20795-20798, 20801-20806, 20844, 20852-20855 in August 1902 and 20936 in September 1902.

The first of the Espee's Atlantics, this class of Vauclain compounds was divided into the 10 that served the Southern Pacific itself and the 6 that went to its Texas-based subsidiary, the Texas & New Orleans. Some of these were lettered for the Galveston, Harrisburg & San Antonio.

The Southern Pacific engines were never rebuilt as simple-expansion locomotives and were scrapped in 1923-1930. The T & NO sextet did jettison their compound system and were superheated in 1925; see Locobase 8658.

Class A-1 - 278 (Locobase 8659)

Data from T&NO 3 - 1932 Locomotive Diagrams supplied in May 2005 by Allen Stanley from his extensive collection.

After the Southern Pacific sold several of its A-1 Vauclain Compound Atlantics to the T & NO, this engine suffered a boiler explosion in July 1913. The railway rebuilt it to the specs shown, a design that retained the high-speed aspirations of the original class (albeit with a reduction in driver diameter) but adopted simple-expansion and superheating.

This single-engine class carried on for the T & NO until April 1941.

Class A-3 (Locobase 1431)

Data from "Engines for the Associated Lines," Railway and Locomotive Engineering, Vol 21, No 12 (December 1908), p. 524-525. Most numerous sub-class of the Espee A-class 4-4-2 series, these were Harriman Common Standard engines. Built by Alco (Schenectady and Brooks) and Baldwin from 1904 to 1908.

Westcott (1960) says HCS Atlantics "were good performers, but slippery when starting and a little short on steam on sustained climbing." Given the relatively large boiler and 12" piston valves with 6" travel, one wonders if the shortness of breath could have come instead from the tall drivers. These would have allowed less steam per mile admitted to the cylinders than smaller-drivered engines.

Westcott notes also that these engines could pull the Daylight Limited from Los Angeles to San Luis Obispo (223 miles) without refueling

All were superheated in the 1920s; see Locobase 8660. Almost all received feedwater heaters or cast trailing trucks with starting booster engines. Unusually for modified engines, however, this class retained its inside Stephenson link motion. Four were modified by the railroad as A-6s; see Locobase 111.

Class A-3 - superheated (Locobase 8660)

Data from T&NO 3 - 1932 Locomotive Diagrams supplied in May 2005 by Allen Stanley from his extensive collection.

Superheating the Harriman Atlantics took several forms, including this variation by the T & NO's shops. This set of 4, which bore heralds from the Galveston, Harrisburg & San Antonio (290), Louisiana Western (291), and the Texas & New Orleans itself (289, 292), had fewer tubes than the A-5/A-6 (Locobase 6549 & 111, respectively) and had shorter drivers.

Class A-6 (Locobase 111)

Data from SP Menke All-Time Steam Loco Diagrams supplied in May 2005 by Allen Stanley from his extensive collection.

A-6s were rebuilt from 4 Alco- and Baldwin-built A-3s (Locobase 1431). Fitted with 11,500-lb booster on trailing truck, which was modified to outside bearings. Also equipped with a Worthington feedwater heater.

Class Nc / A-3 / A-5 (Locobase 6549)

Data from SP Menke All-Time Steam Loco Diagrams supplied in May 2005 by Allen Stanley from his extensive collection. See also "Engines for the Associated Lines," Railway and Locomotive Engineering, Vol 21, No 12 (December 1908), p. 524-525. Baldwin works numbers for a follow-on batch were 36214-36218 in March 1911.

The article notes that the big 1908 Alco production for the Associated Lines included 30 Moguls, 10 Atlantics, 24 Ten-wheelers, 43 Consolidations, and 18 switchers. It describes the Harriman Common Standard Atlantics and Moguls in detail, particularly noting all of the components they shared. In the case of these two arrangements, the designers were able to use the same cylinder volume and the same boiler and grate, the principal differences lying in 3 ft 4 in longer tubes and a slightly deeper firebox in the Atlantic.

Of the 1908 order, at least 2 were built for the FC de Sonora of the Mexican lines portion of the SP and 3 went to the Cananea, Rio Yaqui & Pacific. Baldwin's 1911 order supplied 3 more to the CRY &P and 2 more to the FC de Sonora.

They were virtually identical to the A-3s built for the Espee in 1904-1908 (Locobase 1431).

Of the 1911 Baldwins, the first 2 stayed in Mexico, where they operated until being retired in 1934 and scrapped in 1938. The other three moved across the border to the Arizona Eastern, and wound up on the Espee's Pacific Lines in 1924, where they ran until 1935.