Gulf, Mobile & Northern / New Orleans Great Northern 2-10-0 "Decapod" Locomotives in the USA


Class Details by Steve Llanso of Sweat House Media

Class 201 (Locobase 4403)

Data from GM&N 7 - 1924 Locomotive Diagrams supplied in May 2005 by Allen Stanley from his extensive Rail Data Exchange collection. Ilustrations in Linn Wescott (Model Railroader Cyclopedia - Vol 1, 1960) and see Drury (1993), 176. See the detailed overview published by designer Alphonse I Lipetz, "Russian 'Decapod' Locomotives", The Railway Engineer, Volume 43, No 2 (February 1922), pp. 51-54; April 1922, pp. 136-137; July 1922, pp. 249-251; and November 1922, pp. 415-417. (Thanks to Chris Hohl for his 8 February 2019 email correcting the Russian decapods' wheelbases.)

857 2-10-0s were built by Baldwin and Alco (Richmond and Schenectady Works) for the Russian Government (see Locobase 381 for a full description). When that empire was overthrown, some 200 more of the Russian order was diverted to railroads in the US by the USRA. Although all of the Russian decks were built to a common specification, several US railroads published later diagrams that reflected either updates or their own standards of measurements.

Of the ten that went to the GM&N, two were later transferred to the Alabama, Tennessee & Northern as their 425-426. (Thanks to Chris Hohl for inquiring about this pair.)


Class 250 (Locobase 1399)

Data from DeGolyer, Volume 74, pp. 205+, Volume 76, pp 381+ , and Volume 77, pp. 620+. See also GM&O 5 -1945 Locomotive Diagrams supplied in May 2005 by Allen Stanley from his extensive Rail Data Exchange collection, and J Parker Lamb, Railroads of Meridian (), p. 33.. (Thanks to Chris Hohl for his 20 April 2015 email noting the change in fuels from delivery to later in these engines' career; see below.) Works numbers were 57379-57383 in October 1924; 58364-58365 in April 1925, 58373-58375 in May, 59609-59610 in October; 60085-60086 in June 1927, 60097-60098 in July

Sixteen engines of Baldwin's standard catalog light 2-10-0 developed in the 1920s to put engines with this tractive effort on relatively light rails. Their relatively high drivers let them run faster than other Decapod designs. J Parker Lamb says that the railroad referred to them "with pride as the '250 series [referring to their loaded engine weight in thousands of pounds]'" and adds:"[T]hey were its strongest pullers yet had light axle loadings that were necessary on GM&N's light roadbeds."

The first few were delivered with boilers pressed to 215 psi (14.8 bar) and cost $48,500 each. . All of them used 14" (356 mm) piston valves to supply the cylinders. By the time 260-261 were ordered in November 1926, the specs had a "Hereafter" note reporting that the back tubesheet had cracks at the top and recommending that the flange width be increased to 1 1/2" (38.1 mm).

Chris Hohl pointed out that the class was delivered as coal burners with later conversions to oil fuel. Locobase realized that they had hefty fuel capacities regardless of fuel from the 18 tons of coal as delivered to the 21 tons in later tenders to the 3,500 US gallons of oil fuel.

Some were retrofitted with a Coffin feedwater heater that wrapped like a horse collar around the firebox, bigger air pumps, and a second sand dome.


Class 90 (Locobase 6907)

Data from NOGN 1928 Locomotive Diagrams supplied in May 2005 by Allen Stanley from his extensive Rail Data Exchange collection. See also the quite detailed overview published by designer Alphonse I Lipetz, "Russian 'Decapod' Locomotives", The Railway Engineer, Volume 43, No 2 (February 1922), pp. 51-54; April 1922, pp. 136-137; July 1922, pp. 249-251; and November 1922, pp. 415-417. (Thanks to Chris Hohl for his 8 February 2019 email correcting the Russian decapods' wheelbases.)

As noted in several other Locobase entries, 857 2-10-0s were built by Baldwin and Alco (Richmond and Schenectady Works) for the Russian Government (see Locobase 381 for a full description). When that empire was overthrown, some 200 more of the Russian order was diverted to railroads in the US by the USRA. Although all of the Russian decks were built to a common specification, several US railroads published later diagrams that reflected either updates or their own standards of measurements.

The NOGN received its two Alco-Richmond decapods in April 1921 and the Baldwin in November 1922. As with the other roads that ran them, the NOGN apparently liked the relatively light-footed axle loadings.

The 92 was sold to the Gainesville Midland as their 201. Locomotive rebuilder/reseller Georgia Car & Locomotive bought the 90 from the GM&O in January 1946. GC&L immediately sold the engine to the Kansas City, Mexico & Orient.

Principal Dimensions by Steve Llanso of Sweat House Media

Class20125090
Locobase ID4403 1399 6907
RailroadGulf, Mobile & Northern (GM&O)Gulf, Mobile & Northern (GM&O)New Orleans Great Northern (GM&O)
CountryUSAUSAUSA
Whyte2-10-02-10-02-10-0
Number in Class10163
Road Numbers201-210250-26590-92
GaugeStdStdStd
Number Built10163
BuilderseveralBaldwinseveral
Year191819231918
Valve GearWalschaertWalschaertWalschaert
Locomotive Length and Weight
Driver Wheelbase (ft / m)18.67 / 5.5920 / 6.1018.67 / 5.59
Engine Wheelbase (ft / m)27.83 / 8.4828.92 / 8.8127.83 / 8.48
Ratio of driving wheelbase to overall engine wheelbase 0.67 0.69 0.67
Overall Wheelbase (engine & tender) (ft / m)60 / 18.2965.08 / 19.84
Axle Loading (Maximum Weight per Axle) (lbs / kg)35,000 / 15,87645,400 / 20,59335,260 / 15,994
Weight on Drivers (lbs / kg)176,300 / 79,968227,060 / 102,993176,000 / 79,832
Engine Weight (lbs / kg)202,500 / 91,853253,730 / 115,090202,000 / 91,626
Tender Loaded Weight (lbs / kg)152,200 / 69,037177,000 / 80,286142,800 / 64,773
Total Engine and Tender Weight (lbs / kg)354,700 / 160,890430,730 / 195,376344,800 / 156,399
Tender Water Capacity (gals / ML)7400 / 28.038500 / 32.207400 / 28.03
Tender Fuel Capacity (oil/coal) (gals/tons / Liters/MT) 8.80 / 818 / 1614.20 / 13
Minimum weight of rail (calculated) (lb/yd / kg/m)59 / 29.5076 / 3859 / 29.50
Geometry Relating to Tractive Effort
Driver Diameter (in / mm)52 / 132157 / 144852 / 1321
Boiler Pressure (psi / kPa)180 / 12.40225 / 15.50180 / 12.40
High Pressure Cylinders (dia x stroke) (in / mm)25" x 28" / 635x71125" x 30" / 635x76225" x 28" / 635x711
Tractive Effort (lbs / kg)51,490 / 23355.5062,911 / 28535.9851,490 / 23355.50
Factor of Adhesion (Weight on Drivers/Tractive Effort) 3.42 3.61 3.42
Heating Ability
Tubes (number - dia) (in / mm)194 - 2" / 51217 - 2" / 51194 - 2" / 51
Flues (number - dia) (in / mm)28 - 5.375" / 13736 - 5.375" / 13728 - 5.375" / 137
Flue/Tube length (ft / m)17 / 5.1817.41 / 5.3117 / 5.18
Firebox Area (sq ft / m2)227 / 21.09229 / 21.27227 / 21.10
Grate Area (sq ft / m2)64.70 / 6.0164.70 / 6.0164.60 / 6
Evaporative Heating Surface (sq ft / m2)2600 / 242.473091 / 287.162600 / 241.64
Superheating Surface (sq ft / m2)579 / 53.79692 / 64.29563 / 52.32
Combined Heating Surface (sq ft / m2)3179 / 296.263783 / 351.453163 / 293.96
Evaporative Heating Surface/Cylinder Volume163.42181.40163.42
Computations Relating to Power Output (More Information)
Robert LeMassena's Power Computation11,64614,55811,628
Same as above plus superheater percentage13,74217,17813,721
Same as above but substitute firebox area for grate area48,21560,80048,215
Power L1877213,1268630
Power MT548.47637.23540.51

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