Nacional de Mexico 2-8-0 "Consolidation" Type Locomotives

Class G-030 (Locobase 3237)

Designed to scale 4 1/2% grades and negotiate 21-deg curves, these were the back-country Consolidations. Hidden within their frames, however, was a layout that would permit conversion to standard-gauge operation. This is seen in the outside bar frame that masked the wheels.

Railway Age (12 Nov 1921)

Class G-031 (Locobase 947)

Probably repeats of 28 Baldwin-built G-030s of 1921. Appeared in Locomotive Cyclopedia of 1947.

Class GR-20 (Locobase 1377)

Delivered in two batches, the latter in 1924. Retirements occurred from 1953 to 1963.

Railway Age (12 Nov 1921)

Specifications

Class G-030 G-031 GR-20

Locobase ID 3237 947 1377

Railroad Nacional de Mexico Nacional de Mexico Nacional de Mexico

Whyte 2-8-0 2-8-0 2-8-0

Road Numbers 300 1137-1191

Gauge 3' 3' Std

Builder Baldwin Alco-Schenectady Baldwin

Year 1921 1936 1921

Valve Gear Walschaert Walschaert Walschaert

Locomotive Length and Weight

Driver Wheelbase 11.50' 11.50' 15'

Engine Wheelbase 18.92' 18.92' 23.42'

Ratio of driving wheelbase to overall engine wheebase 0.61 0.61 0.64

Overall Wheelbase (engine & tender) 47.04' 46.67' 58.42'

Axle Loading (Maximum Weight per Axle)

Weight on Drivers 103000 lbs 110000 lbs 158100 lbs

Engine Weight 113200 lbs 118000 lbs 174960 lbs

Tender Light Weight 245000 lbs 90000 lbs 245000 lbs

Total Engine and Tender Weight 358200 lbs 208000 lbs 419960 lbs

Tender Water Capacity 3600 gals 3600 gals

Tender Fuel Capacity (oil/coal) 1510 gals gals gals

Minimum weight per yard of rail on which locomotive could run 42.92 lb rail 45.83 lb rail 65.88 lb rail

Geometry Relating to Tractive Effort

Driver Diameter 41" 41" 55"

Boiler Pressure 180 psi 180 psi 180 psi

Cylinders (dia x stroke) 18" x 22" 18" x 22" 21" x 28"

Tractive Effort 26600 lbs 26600 lbs 34350 lbs

Factor of Adhesion (Weight on Drivers/Tractive Effort) 3.87 4.14 4.60

Heating Ability

Firebox Area 79 sq. ft 90 sq. ft 144 sq. ft

Grate Area 18.70 sq. ft 18.70 sq. ft 49.80 sq. ft

Evaporative Heating Surface 1661 1233 1808

Superheating Surface 339 409

Combined Heating Surface 1661 1572 2217

Evaporative Heating Surface/Cylinder Volume 256.35 190.29 161.07

Computations Relating to Power Output (More Information)

Robert LeMassena's Power Computation 3366 3366 8964

Same as above plus superheater percentage 3366 4091.87 10617.71

Same as above but substitute firebox area for grate area 14220 19693.51 30701.81

Power L1 3902.87 8986.48 9127.10

Power MT 334.15 720.43 509.09

Specifications
Class	G-030	G-031	GR-20
Locobase ID	3237	947	1377
Railroad	Nacional de Mexico	Nacional de Mexico	Nacional de Mexico
Whyte	2-8-0	2-8-0	2-8-0
Road Numbers		300	1137-1191
Gauge	3'	3'	Std
Builder	Baldwin	Alco-Schenectady	Baldwin
Year	1921	1936	1921
Valve Gear	Walschaert	Walschaert	Walschaert
	Locomotive Length and Weight
Driver Wheelbase	11.50'	11.50'	15'
Engine Wheelbase	18.92'	18.92'	23.42'
Ratio of driving wheelbase to overall engine wheebase	0.61	0.61	0.64
Overall Wheelbase (engine & tender)	47.04'	46.67'	58.42'
Axle Loading (Maximum Weight per Axle)
Weight on Drivers	103000 lbs	110000 lbs	158100 lbs
Engine Weight	113200 lbs	118000 lbs	174960 lbs
Tender Light Weight	245000 lbs	90000 lbs	245000 lbs
Total Engine and Tender Weight	358200 lbs	208000 lbs	419960 lbs
Tender Water Capacity	3600 gals	3600 gals
Tender Fuel Capacity (oil/coal)	1510 gals	gals	gals
Minimum weight per yard of rail on which locomotive could run	42.92 lb rail	45.83 lb rail	65.88 lb rail
	Geometry Relating to Tractive Effort
Driver Diameter	41"	41"	55"
Boiler Pressure	180 psi	180 psi	180 psi
Cylinders (dia x stroke)	18" x 22"	18" x 22"	21" x 28"
Tractive Effort	26600 lbs	26600 lbs	34350 lbs
Factor of Adhesion (Weight on Drivers/Tractive Effort)	3.87	4.14	4.60
	Heating Ability
Firebox Area	79 sq. ft	90 sq. ft	144 sq. ft
Grate Area	18.70 sq. ft	18.70 sq. ft	49.80 sq. ft
Evaporative Heating Surface	1661	1233	1808
Superheating Surface		339	409
Combined Heating Surface	1661	1572	2217
Evaporative Heating Surface/Cylinder Volume	256.35	190.29	161.07
	Computations Relating to Power Output (More Information)
Robert LeMassena's Power Computation	3366	3366	8964
Same as above plus superheater percentage	3366	4091.87	10617.71
Same as above but substitute firebox area for grate area	14220	19693.51	30701.81
Power L1	3902.87	8986.48	9127.10
Power MT	334.15	720.43	509.09

Photos

G-20 40 (National Museum of Mexican Railroads, Puebla, PUE, Mexico. Photo courtesy Juan Viladrosa)
G-20 40 (National Museum of Mexican Railroads, Puebla, PUE, Mexico. Photo courtesy Toshihiko Yamada)
G-023 67 (Monument to Revolution Museum, Mexico City. Photo courtesy Roberto Ruelas-Gomez)
G-023 67 (Monument to Revolution Museum, Mexico City. Photo courtesy Roberto Ruelas-Gomez)
G-023 67 (Monument to Revolution Museum, Mexico City. Photo courtesy Fernando Villanueva de G.)
G-023 67 (Monument to Revolution Museum, Mexico City. Photo courtesy Fernando Villanueva de G.)
G-030 269 (Toluca, Estado de Mexico. Toshihiko Yamada)
G-030 269 (Toluca, Estado de Mexico. Toshihiko Yamada)
G-030 281 (Old FCI Terminal, Jalapa, VER)
G-030 286 (Cenro Cultural Sor Juana Museum, Nepantla. Photo courtesy Juan Viladrosa)
G-030 286 (Cenro Cultural Sor Juana Museum, Nepantla. Photo courtesy Juan Viladrosa)
GR-3 296 (west of depot, Acambaro, GTO)
GR-3 900 (depot, Durango, DGO)
GR-3 903 (east of depot, Acambaro, GTO. Photo courtesy Roberto Ruelas-Gomez)
GR-3 903 (east of depot, Acambaro, GTO. Photo courtesy Roberto Ruelas-Gomez)
GR-3 907 (Canitas de Felipe Pescador, ZAC. Photo courtesy Toshihiko Yamada)
GR-20 1150 (National Museum of Mexican Railroads, Puebla. Photo courtesy Toshihiko Yamada)
GR-20 1182
GR-20 1182 (Alameda Park, San Luis Potosi, San Luis Potosi. Photo courtesy Toshihiko Yamada)
GR-28 212 (Rts 119 & 136, Apizaco, Tlaxcala, Mexico. Photo courtesy Toshihiko Yamada)
GR-28 212 (Rts 119 & 136, Apizaco, Tlaxcala, Mexico. Photo courtesy Toshihiko Yamada)
GR-34 1399
GR-34 1399 (Ciudad Frontera, COA)

Credits

Introduction and specifications provided by Steve Llanso of Sweat House Media.