St Louis Southwestern 2-8-0 "Consolidation" Locomotives in the USA


Class Details by Steve Llanso of Sweat House Media

Class G1 (Locobase 8474)

Data from StL&SW 1 - 1932 Folio 725 Locomotive Diagrams supplied in May 2005 by Allen Stanley from his extensive Rail Data Exchange. See also DeGolyer, Volume 30, p. 6 and Volume 32, p. 47. Joseph A Strapac, Cotton Belt Locomotives (Huntington, Calif: Shade Tree Books, 1977, reprinted in 1999 by Indiana University Press), p. 96. (Thanks to Chris Hohl for his 9 September 2016 email pointing out that most Cotton Belts engines were delivered as coal burners.) Works numbers were 29376-29377, 29407-29408, 29440-29441, 29447, 29497-29498, 29510 in November 1906.

Joe Strapac observed that "Despite their small size and unimpressive specifications", these engines began "...the fourth distinct generation of Cotton Belt motive power." They were delivered as coal-burners, as were most St Louis-Southwestern locomotives at the time. (By 1932, however, oil burners outnumbered coal burners by 3:1 in the locomotive diagram book referenced above.)

Strapac also noted that "[a]lthough Walschaerts [sic] valve gear was available, the 500-509 came with Stephenson link motion and slide valves and the almost inevitable spoked pilot wheels."

In the 1920s, the SSW superheated five of the locomotives in their original 2-8-0 layout; see Locobase 8475. Three more--504, 509, and 500--were converted to 0-8-0 switchers in 1928-1929. The other two, said Strapac, were to be converted as well and thus didn't receive the superheater upgrades, but the economic impacts of the Great Depression that began in late 1929 annulled those plans, leaving them essentially unchanged. 508 was scrapped in 1934 and 506 in 1937.


Class G1 - superheated (Locobase 8475)

Data from StL&SW 1 - 1932 Folio 725 Locomotive Diagrams supplied in May 2005 by Allen Stanley from his extensive Rail Data Exchange. See also Joseph A Strapac, Cotton Belt Locomotives (Huntington, Calif: Shade Tree Books, 1977, reprinted in 1999 by Indiana University Press), p. 96. (Thanks to Chris Hohl for his 9 September 2016 email commenting on valve gear that led to a review of this entry.)

Delivered in 1906 as saturated-steam locomotives (Locobase 8474), this class converted as shown beginning in 1925 (2), followed by 2 more in 1928, and the last to be modified in 1930.. The result is a powerful drag-freight locomotive with a decent level of superheat and relatively large 12" (305 mm) piston valves to deliver that dry steam to the cylinders. Moreover, unlike most such conversions, the total amount of heating surface remained almost the same.

Also unusual for conversions undertaken so late in the era, the shops dropped the boiler pressure. Since the increase in piston diameter meant no reduction in tractive effort, the designers might have seized an opportunity to reduce maintenance demands.

Note that 500, 504, and 509 also went through the boiler, cylinder, and valve gear upgrade, but lost their leading truck as part of a conversion in their role to heavy switching. They put substantially more weight on their drivers, increasing loaded weight to 213,000 lb (99,615 kg) and maximum axle loading to 55,900 lb (25,356 kg) and boiler pressure to 190 psi (13.1 bar) and thus tractive effort to 45,405 lb (20,595 kg or 201.97 kN).

At least one G1 (503) lost five tubes in order to accept a new firebox that was fitted with two Nicholson thermic syphons measuring a total of 43 sq ft. The result was a boiler with three more total sq ft of evaporative heating surface, but a firebox heating surface that had grown to 263 sq ft (24.45 sq m). The other four were equipped with brick arches.


Class G2 (Locobase 16158)

Data from StL&SW 1 - 1932 Folio 725 Locomotive Diagrams supplied in May 2005 by Allen Stanley from his extensive Rail Data Exchange. See also DeGolyer, Volume 30, p. 6 and Volume 32, p. 47. Joseph A Strapac, Cotton Belt Locomotives (Huntington, Calif: Shade Tree Books, 1977, reprinted in 1999 by Indiana University Press), p. 91. (Thanks to Chris Hohl for his 31 March 2015 and 12 March 2020 emails suggesting the inclusion of original coal capacity and tender weight.) G2 works numbers were 33182-33186, 33203, 33220-33221, 33226-33227 in February 1909; 34805-34807, 34856-34859, 34870-34871 in June; 34912 in July; 34805-34807, 34856-34859, 34870-34871 in June 1910; 34912 in July.

These coal-burning Consolidations were delivered in 1909-1910 as slightly modified variants of the G1s produced three years earlier (Locobase 8474). They had the same diameter cylinders, but a two-inch (50.8 mm) longer stroke.

When delivered, the 2-8-0s were relative lightweights. They carried saturated boilers and admitted steam to the cylinders through Richardson balanced slide valves. Their tenders carried 15 tons (13.65 metric tons) of coal and weighed 160,000 lb (72.575 kg) loaded.

Note that the design retained the narrow firebox between the drivers.

Locobase describes the superheated G2s in Locobase 8476.


Class G2 - superheated (Locobase 8476)

Data from StL&SW 1 - 1932 Folio 725 Locomotive Diagrams supplied in May 2005 by Allen Stanley from his extensive Rail Data Exchange. Works numbers were 33182-33186, 33203, 33220-33221, 33226-33227 in February 1909; 34805-34807, 34856-34859, 34870-34871 in June; and 34912 in July.

These Consolidations were delivered in 1909-1910 (Locobase 16158) as slightly modified variants of the G1s produced three years earlier (Locobase 8474). Like those engines, this class was soon superheated, the fitting of bigger cylinders being a relatively unusual change. The greater volume and slightly higher boiler pressure meant still more power for the grade. Capable of a substantial level of superheat and fitted with relatively large 12" (305 mm) piston valves to deliver that dry steam to the cylinders, these were even more powerful. (514 and 519 were fitted with a "Simplified" steam chest in which the slide valve was replaced by a 10"/254 mm piston valve.)

At least three G2 (510-511, 513) lost some 2" tubes in order to accept a new firebox that was fitted with two Nicholson thermic syphons measuring a total of 43 sq ft (4 sq m). The result was a boiler with 6 more total sq ft of evaporative heating surface, but a firebox heating surface that had grown to 280 sq ft(26.01 sq m).

524 & 526 were later converted to 0-8-0 switchers. Six were sold to the S P de M in Mexico in 1947 and the rest were retired between 1945 and 1953.


Class K-1 - 771 (Locobase 409)

Data from StL&SW 1 - 1945 Folio 725 Locomotive Diagrams supplied in May 2005 by Allen Stanley from his extensive Rail Data Exchange. See also DeGolyer, Vol 68, pp. 345+. Works numbers were 56513-56517, 56588-56597 in May 1923.

This last set of Consolidations continued the general line of 25"x 30" 2-8-0s that Baldwin supplied to the St Louis-Southwestern over a 10-year period. By now boiler pressure had crept to 200 psi, but many other characteristics were essentially unchanged. In the case of this 15-engine batch, however, there was a slight decrease in heating surface and in the 53 sq ft (4.9 sq m) of surface area contained in the two Nicholson thermic syphons that would be added soon after delivery. Piston valves measured 14" (356 mm) in diameter.

By the 1940s, the locomotives sported cross-balanced, disc drivers. Only the 764 failed to last until the 1950s; it suffered an explosion in December 1945. All of the others were sold for scrap between February 1952 and May 1956.


Class K1 (Locobase 8477)

Data from StL&SW 1 - 1932 Folio 725 Locomotive Diagrams supplied in May 2005 by Allen Stanley from his extensive Rail Data Exchange. See also "Ten-Wheeler Locomotive for the St Louis Southwestern", Railway and Locomotive Engineering, Volume 26, No. 9 (September 1913), pp. 312-313; and DeGolyer, Volume 48, pp. 69+ and pp. 81+. (Thanks to Chris Hohl for his 31 March 2015 and 12 March 2020 emails suggesting the inclusion of original coal capacity and tender weight.) Works numbers were 38341-38344, 38353, 38393-8395 in September 1912; 38434-38437, 38517-38522 in October; 40059-40064 in June 1913; and 40158-40160, 40214 in July.

Baldwin began delivery of this large class of coal-burning Consolidations in 1912. Compared to earlier StL-SW 2-8-0s, this class had wider grates but, surprisingly, less firebox heating surface. A principal change was the inclusion of a superheater, whose hotter steam served larger cylinders. Also, K1s were equipped with 14" (356 mm) piston valves and Walschaert gear from the beginning. All in all, it was a scaled-up version of the G2 (Locobase 8476) in which the boiler's size compared to the cylinder volume remained about the same but the grate grew substantially.

In its initial configuration, the design's tender carried 15 tons (13.65 metric tons) of coal and weighed 171,700 lb (77,882 kg).

Baldwin's spec includes a "For Hereafter note that lists the complaints registered in a 16 December 1912 letter from the Cotton Belt's superintendent of motive power T E Adams. None of the defects seem significant to the casual reader, but the railroad spend good money and these were the items that failed to satisfy:

"Driving spring equalizer bearings and pin holes not bushed

Omission of flange on bottom of ash-pan doors

Blow-off cock 1 1/2" instead of 2"

Front end netting not in accordance with specifications

Uncoupling lever brackets not in accordance with specifications

Omission of cast iron tender steps.

The note adds that Baldwin replied on 3 January 1913 and refers to "other BLW correspondence accompanying Mr Adams letter."

Beginning in 1917, tweaks to the design created a variant deserving its own entry (Locobase 8478).


Class K1 - 61 (Locobase 8478)

Data from StL&SW 1 - 1932 Folio 725 Locomotive Diagrams supplied in May 2005 by Allen Stanley from his extensive Rail Data Exchange. See also DeGolyer, Volume 55, pp. 218+. Works numbers were 44572-44576, 44632-44634, and 44677-44680 in December 1916.

Although as delivered, these dozen Consolidations were appreciably different from the earlier K1s in only three minor respects: driver diameter, which grew by 2" (51 mm), driving wheelbase, which came a foot longer, and boiler pressure, which swelled by only 5 psi. They still had the same 14" (356 mm) piston valves, 29 sq ft (2.7 sq m) of arch tubes contributing to firebox heating surface, and the same boiler.

Locobase has chosen to document the three class members that were given two Nicholson thermic syphons each in place of the arch tubes. While they lost 15 sq ft (1.4 sq m) of arch tubes and 35 sq ft (3.25 sq m) in tube heating surface area, they gained 61 1/2 sq ft (5.7 sq m) in direct heating surface in a form that had been shown to convey significantly more heat to water per unit of area.


Class K1 - 750 (Locobase 8480)

Data from StL&SW 1 - 1945 Folio 725 Locomotive Diagrams supplied in May 2005 by Allen Stanley from his extensive Rail Data Exchange. See also DeGolyer, Volume 61, pp. 367+. (Thanks to Chris Hohl for his 31 March 2015 and 12 March 2020 emails suggesting the inclusion of original coal capacity and tender weight.) Works numbers were 53483 in July 1920; 53532, 53561-53562 in August; 53620-53621, 53652-53653, 53690-53691 in September; 54240, 54377-54380, 54447, 54488-54492 in January 1921.

Baldwin added more K1 Consolidations after World War I that were virtually identical to those supplied before the Great War (Locobase 8478), although now they used Baker radial valve gear to actuate their 14"(356 mm) diameter piston valves. Originally delivered as coal burners, this batch trailed tenders carrying 14 tons () of coal and weighing 178,000 lb (80,740 kg).

The original firebox had 214.6 sq ft (19.9 sq m), of which 28.6 sq ft (2.65 sq m) came from two arch tubes. Only the arch tubes were installed by Baldwin; the Cotton Belt added the brick arch in its own shops. By the 1940s, most of the class had been fitted with 62 sq ft of Nicholson thermic syphons (two) and this is represented in the specs.

See Locobase 409 for the 1923 Baldwins, which had some differences from this batch.

When the Cotton Belt began jettisoning its steam fleet, it found two principal buyers. The FerroCarril de Pacifico took twelve of the class (750, 752, 754, 756-757, 760-761, 763, 765-766, 769-770), most of which it scrapped in the mid-to-late 1950s. One -- 638 (ex-756) -- survived to be classed GR-52 by the Nacional de Mexico. The Espee took four as their class C-11 -- 751, 753, 755, 768 -- and renumbered them 2861-2864. 2863 was scrapped first in March 1960. The other 3 were broken up in April 1961.

Principal Dimensions by Steve Llanso of Middle Run Media
ClassG1G1 - superheatedG2G2 - superheatedK-1 - 771
Locobase ID8474 8475 16158 8476 409
RailroadSt Louis Southwestern (Cotton Belt)St Louis Southwestern (Cotton Belt)St Louis Southwestern (Cotton Belt)St Louis Southwestern (Cotton Belt)St Louis Southwestern (Cotton Belt)
CountryUSAUSAUSAUSAUSA
Whyte2-8-02-8-02-8-02-8-02-8-0
Number in Class105202015
Road Numbers500-509501-503, 505, 507510-529510-529771-785
GaugeStdStdStdStdStd
Number Built102015
BuilderBaldwinCotton BeltBaldwinCotton BeltBaldwin
Year1906192519091923
Valve GearStephensonWalschaertStephensonWalschaertBaker
Locomotive Length and Weight
Driver Wheelbase (ft / m)16 / 4.8816 / 4.8816 / 4.8816 / 4.8817.50 / 5.33
Engine Wheelbase (ft / m)24.50 / 7.4724.50 / 7.4724.50 / 7.4724.50 / 7.4726.50 / 8.08
Ratio of driving wheelbase to overall engine wheelbase 0.65 0.65 0.65 0.65 0.66
Overall Wheelbase (engine & tender) (ft / m)58.23 / 17.7558.27 / 17.7658.23 / 17.7558.02 / 17.6863.38 / 19.32
Axle Loading (Maximum Weight per Axle) (lbs / kg)44,500 / 20,18545,250 / 20,52544,500 / 20,18546,250 / 20,97956,895 / 25,807
Weight on Drivers (lbs / kg)169,000 / 76,657178,000 / 80,740173,000 / 78,472182,000 / 82,554213,745 / 96,953
Engine Weight (lbs / kg)190,000 / 86,183201,000 / 91,172195,000 / 88,451206,000 / 93,440243,775 / 110,575
Tender Loaded Weight (lbs / kg) / 70,035158,035 / 71,684154,400 / 70,035164,000 / 74,389195,000 / 88,451
Total Engine and Tender Weight (lbs / kg) / 156,218359,035 / 162,856349,400 / 158,486370,000 / 167,829438,775 / 199,026
Tender Water Capacity (gals / ML)7000 / 26.527000 / 26.527000 / 26.527500 / 28.419000 / 34.09
Tender Fuel Capacity (oil/coal) (gals/tons / Liters/MT) / 123250 / 12,3013250 / 12,3013350 / 12,6803500 / 13,248
Minimum weight of rail (calculated) (lb/yd / kg/m)70 / 3574 / 3772 / 3676 / 3889 / 44.50
Geometry Relating to Tractive Effort
Driver Diameter (in / mm)55 / 139755 / 139755 / 139755 / 139761 / 1549
Boiler Pressure (psi / kPa)200 / 1380175 / 1210200 / 1380180 / 1240200 / 1380
High Pressure Cylinders (dia x stroke) (in / mm)22" x 28" / 559x71123.5" x 28" / 597x71122" x 30" / 559x76223.5" x 30" / 597x76225" x 30" / 635x762
Tractive Effort (lbs / kg)41,888 / 19000.1041,820 / 18969.2644,880 / 20357.2546,088 / 20905.1952,254 / 23702.04
Factor of Adhesion (Weight on Drivers/Tractive Effort) 4.03 4.26 3.85 3.95 4.09
Heating Ability
Tubes (number - dia) (in / mm)346 - 2" / 51206 - 2" / 51346 - 2" / 51206 - 2" / 51232 - 2" / 51
Flues (number - dia) (in / mm)32 - 5.375" / 13732 - 5.375" / 13732 - 5.375" / 137
Flue/Tube length (ft / m)14.10 / 4.3013.42 / 4.0914.12 / 4.3013.42 / 4.0915 / 4.57
Firebox Area (sq ft / m2)224 / 20.81222 / 20.62224 / 20.81239 / 22.20239 / 22.20
Grate Area (sq ft / m2)32.70 / 3.0432.70 / 3.0432.70 / 3.0432.70 / 3.0452.50 / 4.88
Evaporative Heating Surface (sq ft / m2)2761 / 256.502257 / 209.762761 / 256.602274 / 211.342748 / 255.39
Superheating Surface (sq ft / m2)530 / 49.26530 / 49.26591 / 54.93
Combined Heating Surface (sq ft / m2)2761 / 256.502787 / 259.022761 / 256.602804 / 260.603339 / 310.32
Evaporative Heating Surface/Cylinder Volume224.11160.53209.17151.00161.27
Computations Relating to Power Output (More Information)
Robert LeMassena's Power Computation654057236540588610,500
Same as above plus superheater percentage654068106540700412,390
Same as above but substitute firebox area for grate area44,80046,23244,80051,19456,404
Power L1577592845390902711,052
Power MT301.34459.95274.75437.39455.97

Principal Dimensions by Steve Llanso of Middle Run Media
ClassK1K1 - 61K1 - 750
Locobase ID8477 8478 8480
RailroadSt Louis Southwestern (Cotton Belt)St Louis Southwestern (Cotton Belt)St Louis Southwestern (Cotton Belt)
CountryUSAUSAUSA
Whyte2-8-02-8-02-8-0
Number in Class281235
Road Numbers550-577578-590750-770
GaugeStdStdStd
Number Built281235
BuilderBaldwinBaldwinBaldwin
Year191319161920
Valve GearWalschaertWalschaertBaker
Locomotive Length and Weight
Driver Wheelbase (ft / m)16.50 / 5.0317.50 / 5.3317.50 / 5.33
Engine Wheelbase (ft / m)25.50 / 7.7726.50 / 8.0826.50 / 8.08
Ratio of driving wheelbase to overall engine wheelbase 0.65 0.66 0.66
Overall Wheelbase (engine & tender) (ft / m)62.69 / 19.1162.85 / 19.1663.67 / 19.41
Axle Loading (Maximum Weight per Axle) (lbs / kg)53,000 / 24,04053,500 / 24,26754,700 / 24,812
Weight on Drivers (lbs / kg)209,000 / 94,801211,000 / 95,708212,300 / 96,298
Engine Weight (lbs / kg)239,000 / 108,409243,000 / 110,223243,000 / 110,223
Tender Loaded Weight (lbs / kg)208,000 / 94,347195,000 / 88,451195,000 / 88,451
Total Engine and Tender Weight (lbs / kg)447,000 / 202,756438,000 / 198,674438,000 / 198,674
Tender Water Capacity (gals / ML)9000 / 34.099000 / 34.099000 / 34.09
Tender Fuel Capacity (oil/coal) (gals/tons / Liters/MT)3250 / 12,3013500 / 13,2483500 / 13,248
Minimum weight of rail (calculated) (lb/yd / kg/m)87 / 43.5088 / 4488 / 44
Geometry Relating to Tractive Effort
Driver Diameter (in / mm)57 / 144861 / 154961 / 1549
Boiler Pressure (psi / kPa)185 / 1280190 / 1310190 / 1310
High Pressure Cylinders (dia x stroke) (in / mm)25" x 30" / 635x76225" x 30" / 635x76225" x 30" / 635x762
Tractive Effort (lbs / kg)51,727 / 23463.0049,641 / 22516.8149,641 / 22516.81
Booster (lbs)13,320
Factor of Adhesion (Weight on Drivers/Tractive Effort) 4.04 4.25 4.28
Heating Ability
Tubes (number - dia) (in / mm)245 - 2" / 51235 - 2" / 51237 - 2" / 51
Flues (number - dia) (in / mm)32 - 5.375" / 13732 - 5.375" / 13732 - 5.375" / 137
Flue/Tube length (ft / m)15 / 4.5715 / 4.5715 / 4.57
Firebox Area (sq ft / m2)201 / 18.67243.50 / 22.62244 / 22.67
Grate Area (sq ft / m2)52.50 / 4.8852.50 / 4.8852.50 / 4.88
Evaporative Heating Surface (sq ft / m2)2786 / 258.922751 / 255.672751 / 255.67
Superheating Surface (sq ft / m2)578 / 53.72591 / 54.93591 / 54.93
Combined Heating Surface (sq ft / m2)3364 / 312.643342 / 310.603342 / 310.60
Evaporative Heating Surface/Cylinder Volume163.50161.44161.44
Computations Relating to Power Output (More Information)
Robert LeMassena's Power Computation971399759975
Same as above plus superheater percentage11,36411,77111,771
Same as above but substitute firebox area for grate area43,50654,59354,705
Power L1927510,52810,531
Power MT391.35440.00437.43

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