Atlanta & West Point / Georgia Railroad / West Point Route / Western Railway of Alabama 4-6-2 "Pacific" Locomotives in the USA


Class Details by Steve Llanso of Sweat House Media

Class P (Locobase 7319)

Data from A & WP-WRA 11 - 1949 locomotive diagrams supplied in May 2005 by Allen Stanley from his extensive Rail Data Exchange. Works numbers were 54037-54038 in June 1913.

Although relatively small and possessing a modest amount of calculated tractive effort, this design seems to have struck a good balance between cylinder volume and boiler size. It was a light Pacific with passenger-train drivers that gave decades of good service.


Class P (Locobase 11418)

Data from "Locomotive Building," The Railroad Gazette, Vol XLII, No 23 (7 June 1907), p 784-785. The Western Railway of Alabama procured another Rogers Pacific at the same time; see Locobase 11419. Works number was 43024 in March 1907.

As the RG acknowledged, this locomotive had a big boiler for its cylinder volume, observing that the ratio of 287:1 was "...a figure which would indicate a large boiler capacity for sustained high speed." Accompanying the larger boiler was a large enough grate that "there should be no difficulty, with an average grade of bituminous coal, in generating plenty of steam without forcing the fire to an uneconomical rate of combustion."

The author helpfully "calls attention" to the flexible staybolts used along the front and top of the side sheets of the firebox, the forward slope of the tubesheet, as well as 38 sq ft of arch tubes, "... all indicative of current practice."

In 1922, the 250 was rebuilt with superheaters, piston valves, and Walschaert valve gear. Renumbered 251, the engine was sold to the Georgia Railroad in 1934, which reconditioned the engine in 1937, taking the opportunity to fit it with Southern valve gear, and renumbered it 254.


Class P (Locobase 11419)

Data from "Locomotive Building," The Railroad Gazette, Vol XLII, No 23 (7 June 1907), p 784-785. Works number was 43025 in March 1907.

See Locobase 11418 for details on this 2-locomotive class, one of which went to the West Point, the other to the WRA as shown in the specs. Alco-Richmond added the 151 in 1910 that was fitted with Walschaert gear from the beginning.

Like the 250 on the WPR, the 150 was updated with superheaters, piston valves, and Walschaert valve gear in 1922-1923. Renumbered 152, the engine was sold to the Georgia Railroad in 1934. 151 was sold to the GaR in 1936 - the locomotives were renumbered 252-253 and rebuilt one more time with 73" drivers. The two served out their time on the Georgia, retiring in 1953-1954.


Class P - updated (Locobase 7326)

Data from GA 5 - 1947 locomotive diagrams supplied in May 2005 by Allen Stanley from his extensive Rail Data Exchange.

This trio of light Pacifics originally were delivered to the Atlanta & West Point in 1907 by Rogers (works #43024) as 251 and as Western Railway of Alabama 150 (works #43025); 151 was delivered to the WRA in 1910 by Richmond (works #48868). The A & WP rebuilt 251 with piston valves and Walschaerts gear and later sold it to the GRR in 1934. WRA sold its 151 to the GRR in 1934 and added the 150 (by then renumbered 252) in 1936.

In 1938, the GRR reworked them yet again, fitting them with outside-journal trailing trucks and 254 was fitted with Southern valve gear.

This variegated threesome then served the Georgia RR until the demise of steam in 1954.


Class P-74 (Locobase 6953)

Data from locomotive diagram published by Bill Dennington on George Gelwood's [link] website accessed 21 September 2005. Supplemented by A&WP-WRA 10 - 1945 locomotive diagrams supplied in May 2005 by Allen Stanley from his extensive Rail Data Exchange. (Thanks to Chris Hohl for his 13 August 2018 email noting the updates to the 290 when she was restored to excursion-train service in 1990; and for his 7 September 2018 email noting the driver diameter difference.) Works numbers were 7008-7009 in March 1926.

Dennington explains that this two-locomotive order was split between the WPR constituents Atlanta & West Point (290) and the Western Railway of Alabama (190). The two covered the Southern System's Crescent from Atlanta to Montgomery, Ala. When delivered, the pair rolled on 73" (1,854 mm) drivers, but thicker tires soon raised the nominal diameter to the 74" shown.

His summary comment on this pair suffices: "The USRA design [Locobase 172] on locomotives was classic and beautiful. Lima built a very good version of the design when they built 290 and 190." Compared to the Southern's more famous Ps-4s, these engines had a higher superheater area and ratio and 14" piston (356 mm) valves. The diagram does not show if the P-74s had arch tubes. The boiler did have a combustion chamber, but Locobase doesn't know its dimensions.

Like the Ps-4s, the valves had outside lap of 1 1/4" (32 mm), full-gear lead of 1/4" (6.35 mm), but a total travel of 7" (178 mm), 1/2" (12.7 mm) less than the Ps-4. Dennington's comment, recorded below, that they handled heavy trains effortlessly stems in large part from having a large boiler, lots of cylinder volume with generous steam admission.

Both engines were retired in 1954 and the 190 went to the scrapyard. A quickly formed 290 Club persuaded the AW&P to place the 290 on display.

Chris Hohl notes the restoration of the 290 for operation on the New Georgia Railroad in 1989 included providing a much bigger tender that carried 9,500 gallons of water and 20 tons of coal; its original bearings were replaced by roller bearings and tender weight grew by 1,500 lb (680 kg). By 1994, the 290 needed repairs and opportunities for running the engine had dried up. It was placed in storage. A 10 April 2017 report by Kevin Keefe in Classic Trains Magazine that the Southeastern Railway Museum's cosmetic restoration but running gear repairs in the 2000s meant the locomotive could run again if a well-endowed group could support its operation.

Dennington's experience on the 290 in 1992 as she pulled the Southern Crescent was ".... a real thrill ...290 could easily handle 16 to 18 heavy-weight coaches. She was a powerful engine. Running at fifty and sixty mph seemed to be effortless and she rode well at those speeds." He noticed that her stack talk revealed "... a fairly loud exhaust, although deeper and more resonant than the bigger Freedom Train engines."

Principal Dimensions by Steve Llanso of Middle Run Media
ClassPPPP - updatedP-74
Locobase ID7319 11418 11419 7326 6953
RailroadAtlanta & West Point (WPR)Atlanta & West Point (WPR)Western Railway of Alabama (WPR)Georgia Railroad (WPR)West Point Route (WPR)
CountryUSAUSAUSAUSAUSA
Whyte4-6-24-6-24-6-24-6-24-6-2
Number in Class21122
Road Numbers280-281250150253-255290, 190
GaugeStdStdStdStdStd
Number Built2112
BuilderAlco-BrooksAlco-RogersAlco-RogersshopsLima
Year19131907190719381926
Valve GearBakerStephensonStephensonWalschaertBaker
Locomotive Length and Weight
Driver Wheelbase (ft / m)13 / 3.9612.67 / 3.8612.67 / 3.8612.67 / 3.8614 / 4.27
Engine Wheelbase (ft / m)33.25 / 10.1332.46 / 9.8932.46 / 9.8933.79 / 10.3037 / 11.28
Ratio of driving wheelbase to overall engine wheelbase 0.39 0.39 0.39 0.37 0.38
Overall Wheelbase (engine & tender) (ft / m)68.46 / 20.8760 / 18.2960 / 18.2969.17 / 21.0872.44 / 22.08
Axle Loading (Maximum Weight per Axle) (lbs / kg)54,400 / 24,67552,200 / 23,67864,500 / 29,257
Weight on Drivers (lbs / kg)163,000 / 73,936130,000 / 58,967130,000 / 58,967151,300 / 68,629192,500 / 87,317
Engine Weight (lbs / kg)258,000 / 117,027212,000 / 96,162212,000 / 96,162248,600 / 112,763303,500 / 137,665
Tender Loaded Weight (lbs / kg)196,300 / 89,040133,000 / 60,328133,000 / 60,328181,100 / 82,146200,500 / 90,945
Total Engine and Tender Weight (lbs / kg)454,300 / 206,067345,000 / 156,490345,000 / 156,490429,700 / 194,909504,000 / 228,610
Tender Water Capacity (gals / ML)10,000 / 37.887000 / 26.527000 / 26.5210,000 / 37.8811,000 / 41.67
Tender Fuel Capacity (oil/coal) (gals/tons / Liters/MT)17 / 1612 / 1112 / 1115 / 1415 / 14
Minimum weight of rail (calculated) (lb/yd / kg/m)91 / 45.5072 / 3672 / 3684 / 42107 / 53.50
Geometry Relating to Tractive Effort
Driver Diameter (in / mm)74 / 188072 / 182972 / 182973 / 185474 / 1880
Boiler Pressure (psi / kPa)200 / 1380200 / 1380200 / 1380200 / 1380200 / 1380
High Pressure Cylinders (dia x stroke) (in / mm)24" x 28" / 610x71122" x 28" / 559x71122" x 28" / 559x71123" x 28" / 584x71127" x 28" / 686x711
Tractive Effort (lbs / kg)37,051 / 16806.0731,998 / 14514.0731,998 / 14514.0734,494 / 15646.2346,892 / 21269.88
Factor of Adhesion (Weight on Drivers/Tractive Effort) 4.40 4.06 4.06 4.39 4.11
Heating Ability
Tubes (number - dia) (in / mm)191 - 2.25" / 57278 - 2.25" / 57278 - 2.25" / 57142 - 2.25" / 57190 - 2.25" / 57
Flues (number - dia) (in / mm)32 - 5.5" / 14028 - 5.5" / 14045 - 5.5" / 140
Flue/Tube length (ft / m)20 / 6.1020 / 6.1020 / 6.1020 / 6.1019 / 5.79
Firebox Area (sq ft / m2)273 / 25.37276 / 25.65276 / 25.65271 / 25.19327 / 30.38
Grate Area (sq ft / m2)56.55 / 5.2655 / 5.1155 / 5.1154 / 5.0270.80 / 6.58
Evaporative Heating Surface (sq ft / m2)3458 / 321.383532 / 328.253532 / 328.252737 / 254.373669 / 340.86
Superheating Surface (sq ft / m2)894 / 83.09894 / 83.09990 / 91.97
Combined Heating Surface (sq ft / m2)4352 / 404.473532 / 328.253532 / 328.253631 / 337.464659 / 432.83
Evaporative Heating Surface/Cylinder Volume235.88286.69286.69203.34197.68
Computations Relating to Power Output (More Information)
Robert LeMassena's Power Computation11,31011,00011,00010,80014,160
Same as above plus superheater percentage13,68511,00011,00013,50017,134
Same as above but substitute firebox area for grate area66,06655,20055,20067,75079,134
Power L121,6539569956921,94318,891
Power MT878.59486.83486.83959.21649.05

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