Southern Pacific / Texas & New Orleans 4-4-2 "Atlantic" Locomotives in the USA

Class A-1 (Locobase 10786)

Data from Baldwin Locomotive Works, Record of Recent Construction ((1903), No. 39, p. 260-261; and DeGolyer, Volume 25, p.6. 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 ten that served the Southern Pacific itself and the six that went to its Texas-based subsidiaries Texas & New Orleans (3) and Galveston, Harrisburg & San Antonio. (3); they were numbered 273-278. The Baldwin spec said that the class's service was to "haul heavy trains at high speed on comparatively level track." It also showed estimated weights of "about 100,000 lb [45,359 kg]" on the drivers and "about 181,000 lb [82,100 kg)". As Baldwin's own "Recent Record" shows, the builder missed its target by almost 5 tons. A note added to the 1903 order and described in Locobase 5314, advising the company to reduce weight, suggests that this overshoot didn't meet with company approval.

One piston valve 15" (381 mm) in diameter distributed steam to both the HP and LP cylinders on each side of the smokebox.

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 (Locobase 8658)

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

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 two-276-277 then attributed to the Galveston, Harrisburg & San Antonio) and superheated them, completing their transitions to local passenger engines. To achieve greater starting power, the class were fitted with 75% cutoff boosters, all but 274 (C-1) using C-2s.

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 - 278 (Locobase 8659)

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

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-2 (Locobase 5314)

Data from table in July 1904 AERJ; and DeGolyer, Volume 25, pp. 273. See also Angus Sinclair, Twentieth Century Locomotives (New York: Railway and Locomotive Engineering, 1904), pp. 505-506 and "Baldwin Passenger Oil Burner for the Southern Pacific", Railway and Locomotive Engineering, Volume XVI [16], No. 8 (August 1903), p. . Works numbers were 22096, 22110, 22124-22125, 22130, 22151-22152, 22205, 22212 in May 1903.

Drury (1993) notes that these Vauclain compound Atlantics had oil-burning Vanderbilt boilers, which had cylindrical corrugated fireboxes and relatively low firebox heating surface. The firebox's dimensions were stated to be 121" (3,073 mm) long and a diameter of 63 3/8" (1,610 mm).

(Four more built for Texas & Louisiana had conventional boilers). They were based on the A-1s, delivered in 1902 (Locobase 10786). Like those compounds of the time, these engines had two 15" (381 mm) piston valves, each of which served a set of one HP and one LP cylinders on each side of the smokebox.

The spec called for an adhesion weight of 113,000 lb (51,256 kg), but a 15 January 1903 letters asked the Philadelphia builder to "modify design to decrease weight ...except no change to diameter of boiler, which is to remain as originally designed."

Commenting on their looks, Angus Sinclair observed: "The absence of any grate or ash pan gives this engine a clear-cut appearance at the back, and the general design suggests a 'high stepper.' The cab is made of steel plate and the window arrangement looks as if the comfort of the engineer had been taken into consideration."

In any case, these clearly were not the answer as they had been retired by 1915-1918.

Class A-3 (Locobase 1431)

Data from "Engines for the Associated Lines," Railway and Locomotive Engineering, Volume 21, No 12 (December 1908), p. 524-525. See also DeGolyer, Volume 30, pp. 32+; and from"Report of Committe on Power-Chicago, Rock Island & Pacific Railway-Descriptions of Standard Types of Locomotives," American Engineer and Railroad Journal, Volume 79 ( March 1905), pp. 84-86; and "Standard Harriman Pacific Locomotive", American Engineer & Locomotive Journal, Volume 80 , No 3 (March 1906), p. 104. (Thanks to Chris Hohl for his 18 March 2017 email pointing out the oil-burning and coal-burning subclasses and their differing tender capacities and weights as well as the initial boiler pressure setting.).

This was the most numerous sub-class of the Espee A-class 4-4-2 series and were Harriman Common Standard engines. Chris Hohl's investigation of the Baldwin specs established that only two of the dozen engines were coal burners. Although all twelve Vanderbilt tenders carried 7,000 US gallons of water, coal tenders carried 14 tons of coal (12.7 metric tons) and were estimated by Baldwin to weigh 139,716 lb (63,374 kg). (Note: in the Baldwin specs, and presumably calcuated by the Espee, each oil gallon weighed 8 lb (3.63 kg) for a full fuel load of 23,520 lb (10,672 kg).

The 1906 article provides a detailed summary of the parts common to all HCS "Atlantic, Pacific, Consolidation and switch engines". Note the willingness to fix dimensions for relatively large components such as grates, boilers, driver diameters as well as many smaller parts "with exceptions as noted."

Eccentrics: cross heads, piston valves, except switch engines:

driving boxes, except main, which is common to consolidation and Pacific type;

truck wheels, except consolidation, four-wheel engine truck; truck axles;

smokebox arrangements; exhaust nozzle; petticoat pipe;

general design of cab;

grates; grate castings;

boiler diameter, except consolidation; size of firebox, except switcher;

general design of frame and cylinders:

general design of wheel centers

and also boiler and engine fittings as far as possible."

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 mated to relatively small 12" (305 mm) piston valves with 6" (152 mm) travel, one wonders if the shortness of breath might have also derived 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 Rail Data Exchange.

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 Rail Data Exchange. See also Gerald M Best, "Locomotives of the Southern Pacific Company" (Boston, Mass: Railway and Locomotive Historical Society, Baker Library, Harvard business school, 1941). (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 .)

A-6s were rebuilt from four Alco- and Baldwin-built A-3s (Locobase 1431). Frames were reinforced. Fitted with 11,520-lb (5,225 kg) booster on trailing truck, which was modified to outside bearings. Also equipped with a Worthington 3-BL feedwater heater on the left side.

The 3000-3001 (originally Baldwins numbered 3058 and 3063, respectively) were turned out of the shops in August 1927. They later flaunted the Daylight livery on the cab sides and tenders as they pulled the Sacramento Daylight from Lathrop to Sacramento. 3002-3003 originally entered service as Schenectady-built 3031 and Baldwin 3058 and were rebuilt in October 1928. They were always black.

G M Best noted that the rebuild was a success, creating "powerful and speedy" locomotives that were used "a great deal in the valley."

Class A-81 / A-3 (Locobase 4790)

Data from Baldwin Specifications, DeGolyer, Vol 26, pp. 190. See also data from"Report of Committe on Power-Chicago, Rock Island & Pacific Railway-Descriptions of Standard Types of Locomotives," American Engineer and Railroad Journal, Volume 79 ( March 1905), pp. 84-86.Works number was

292 was the single A, Harriman-design Atlantic obtained by the Chicago & Alton after its appearance at the 1904 St Louis Exposition. Like the other HCS Atlantics, steam entered the cylinders through 12" balanced piston valves.

The 292 never actually operated on the C&A's, going into service instead with the Texas & New Orleans subsidiary of the Southern Pacific, where it joined three other Alco-built Atlantics. The 291 came from the Louisiana Western while the 289-290 were originally delivered to the Morgan's Louisiana & Texas Railroad.

The class was later superheated; see Locobase 8660.

NB: Thanks to Gunnar Henrioulle, who wrote to Locobase in July 2012, Locobase determined that the original 4-4-2 entry found in Locobase 4790 was based on inaccurate information. The article "The Modern High Speed Passenger Locomotive", Scientific American - New York, Vol XCII, No 20 (20 May 1905), p 402, reported these data, but described the locomotive as an Atlantic (4-4-2). This put the adhesion weight on two axles, which resulted in a much-too-high axle loading.