Chicago Great Western 2-8-2 "Mikado" Locomotives in the USA

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The Chicago Great Western Railroad received its first "Mikado" type locomotives in 1912 from the Baldwin Locomotive Works. These 2-8-2s were designated as Class L-1 and they were assigned road numbers 700-709. These ten locomotives had 63" diameter drivers, 27" x 30" cylinders, a 187 psi boiler pressure and they exerted 55,178 pounds of tractive effort and each weighed 283,000 pounds. The firebox was 345 square feet which included 31.4 square feet of water tubes, the evaporative heating surface was 4,180 square feet and with the superheater the combined heating surface was 5,060 square feet. Later 81.5 square feet of thernic siphons were added and the piston valve was increased to 15" in diameter.

In 1916, Baldwin delivered another ten similar locomotives to the batch delivered in 1912. They weighed about 3,900 pounds more so they were designated as Class L-2 and were assigned road numbers 710-719. The firebox was 300 square feet which included 39 square feet of arch tubes, the evaporative heating surface was 3,856 square feet and with the superheater the combined heating surface was 4,654 square feet. Later 98 square feet of thermic siphons were added.

In 1918, the USRA assigned ten USRA "Mikado-Light" and they joined the CGW roster as Class L-3 and carried road numbers 750-759. These locomotives had 63" diameter drivers, 26" x 30" cylinders, a 200 psi boiler pressure and they exerted 54,725 pounds of tractive effort and each weighed 292,000 pounds.

A final group of 2-8-2s were ordered from Baldwin and delivered in 1920. Many railroad that were assigned USRA "Mikados" ordered copies of that design the next time they needed more locomotives. The CGW did not follow this pattern and it chose to revert back to its own design of 1912. These last new "Mikados" weighed about 1,400 pounds more, but were otherwise similar. They were designated as Class L-1a and assigned road numbers 720-729. The firebox was 272 square feet which included 81 square feet of thermic syphons, the evaporative heating surface was 4,105 square feet and with the superheater the combined heating surface was 4,985 square feet. The piston valve had a 15" diameter.

There are no surviving CGW 2-8-2 "Mikado" type locomotives.


Roster by Richard Duley

ClassQty.Road NumbersYear BuiltBuilderNotes
L-110700-7091912Baldwin1
L-210710-7191916Baldwin2
L-310750-7591918Baldwin3
L-1a10720-7291920Baldwin4
Notes:
  1. Numbers 700-709 scrapped between 1949 and 1950.
  2. Numbers 710-719 scrapped in 1950.
  3. Numbers 750-759 USRA allocated "Mikado-Light" locomotives. All scrapped between 1939 and 1950.
  4. Numbers 720-729 scrapped between 1942 and 1950.

Class Details by Steve Llanso of Sweat House Media

Class L1 (Locobase 3093)

Data from http://www.geocities.com/zvwrr/chicago_great_western_steam.html for the original 1917 railroad diagrams. See also DeGolyer, Volume 40, pp. 36+ and "Mikado Locomotives, Chicago Great Western", Railway Master Mechanic (September 1912) , p. 419-420. Works numbers were 37965-37970, 37985-37988 in June 1912.

Firebox heating surface included 31.4 sq ft (2.9 sq m) of "water tubes." A later upgrade added 81 sq ft (7.25 sq m) of thermic syphons, which is reflected in the specs. By this time, the piston valves were a healthy 15" (381 mm) in diameter.

These Mikes were an instant success on the CGW, which conducted tests in March 1914 tests among ten each of the CGW's Consolidations, Prairie Mallets, and the Mikados over the Eastern Division between Oelwein, Iowa and Stockton, Ill. The results, according to Railway Age (30 October 1914), proved the value of the superheater and of the 2-8-2 wheel arrangement in general. Mikes handled more tonnage, compiled more gross ton-miles and cost less to run per mile.

Ten more L-1a, which were essentially repeats of the L-1, were supplied by Baldwin in 1920 (see Locobase 6124). Six L-1bs (733, 735-739) were L-1s (nee 703, 705-709) with disk main drivers, mechanical stokers, and new frames; they were rebuilt at Oelwein in 1937-1939; see Locobase 6125. The last Mikado went out with steam in 1950.


Class L1A (Locobase 6124)

Data from 1943 Chicago Great Western diagram book provided by Allen Stanley from his extensive Rail Data Exchange in March 2004. See also DeGolyer, Volume 67, pp. 191+. Works numbers were 53439-53470 in July; August 53511-53513, 53531, 53567-53568, 53614 in August; and 53694 in September.

Firebox heating surface included 31.4 sq ft (2.9 sq m) of "water tubes." Piston valves were a healthy 15" (381 mm) in diameter.

These were repeats of the 1912 L-1s (Locobase 3093) and, except for a slight reduction in tube heating surface, essentially identical. Like the L-1s, these carried on in freight service until the end of steam on the CGW in some cases.


Class L1B (Locobase 6125)

Data from 1943 Chicago Great Western diagram book provided by Allen Stanley from his extensive Rail Data Exchange in March 2004.

Firebox heating surface included 81 sq ft (7.5 sq m) of thermic syphons. Piston valves were 15" in diameter.

This quintet (built as 703, 705-709) was born again at Olewein with new frames, mechanical stoker (hard to believe the crews had served 70 sq ft by hand until then!), and disk main driver on the third axle.


Class L1s (L2) (Locobase 4178)

See http://www.geocities.com/zvwrr/chicago_great_western_steam.html for the original 1917 railroad diagrams. See also DeGolyer, Volume 55, pp. 30+. Works numbers in 1916 were March 43096-43099; April 43190-43193; and May 43290-43291

Firebox heating surface includes 39 sq ft (3.6 sq m) in four arch tubes; later on the shops added thermic syphon; see Locobase 9464.. Similar to the earlier Baldwin Mikes delivered to this road, this class had a combustion chamber, and consequently less superheating surface. This was offset to some extent by an increase in firebox heating surface.

Three L2 became L2B in the 1930s. Although Drury (1993) doesn't say specifically, it's likely that the redesignation reflected the same refit as the L1 class. (That refit had disk drivers, new frames, and a mechanical stoker.) Like the earlier class, these served satisfactorily until the end of steam.


Class L2B (Locobase 9464)

Data from 1943 Chicago Great Western diagram book provided by Allen Stanley from his extensive Rail Data Exchange in March 2004.

The date on this entry reflects the second rebuilding of three -- 710, 712, 716 -- of this 1912 design (for the original, see Locobase 4178). In 1929, the CGW rebuilt the firebox by adding 98 sq ft (9.1 sq m) of thermic syphons and increasing the direct heating surface by 33%. Piston valves measuring a relatively large 15" in diameter (381 mm) distributed steam to medium-sized cylinders.


Class L3 (Locobase 6127)

Data from 1943 Chicago Great Western diagram book provided by Allen Stanley from his extensive Rail Data Exchange in March 2004. See also DeGolyer, Volume 58, pp. 83. Works numbers were 50672, 50729-50731 in November 1918 and 50777-50781, 50803 in December.

Firebox heating surface included 98 sq ft (9.1 sq m) of thermic syphons and 27 sq ft (2.5 sq m) of arch tubes. Piston valves were 14" (356 mm) in diameter.

A few of the 625 USRA light Mikados made it to the CGW where they performed capably for two or three decades. Along the way, the firebox was slightly modified as shown in specs to include the thermic syphons, a practice that the railroad seems to have applied to most of its locomotives.

The first of the L-3s left service in 1939; the last saw steam out in 1950.

Specifications by Steve Llanso of Sweat House Media
ClassL1L1AL1BL1s (L2)L2B
Locobase ID3093 6124 6125 4178 9464
RailroadChicago Great Western (CGW)Chicago Great Western (CGW)Chicago Great Western (CGW)Chicago Great Western (CGW)Chicago Great Western (CGW)
CountryUSAUSAUSAUSAUSA
Whyte2-8-22-8-22-8-22-8-22-8-2
Number in Class10106103
Road Numbers700-709720-729733, 735-739710-719740-742
GaugeStdStdStdStdStd
Number Built101010
BuilderBaldwinBaldwinCGWBaldwinCGW
Year19121920193719161941
Valve GearWalschaertWalschaertWalschaertWalschaertWalschaert
Locomotive Length and Weight
Driver Wheelbase (ft / m)16.50 / 5.0316.50 / 5.0316.50 / 5.0316.50 / 5.0316.50 / 5.03
Engine Wheelbase (ft / m)35.17 / 10.7235.25 / 10.7435.17 / 10.7235.17 / 10.7236.08 / 11
Ratio of driving wheelbase to overall engine wheebase 0.47 0.47 0.47 0.47 0.46
Overall Wheelbase (engine & tender) (ft / m)66.29 / 20.2169.70 / 21.2465.12 / 19.8570.96 / 21.63
Axle Loading (Maximum Weight per Axle) (lbs / kg)
Weight on Drivers (lbs / kg)218,000 / 98,883220,700 / 100,108218,000 / 98,883221,500 / 100,471225,200 / 102,149
Engine Weight (lbs / kg)283,000 / 128,367284,400 / 129,002283,000 / 128,367286,900 / 130,136289,900 / 131,497
Tender Loaded Weight (lbs / kg)152,000 / 68,946162,000 / 73,482196,800 / 89,267143,000 / 64,864199,900 / 90,673
Total Engine and Tender Weight (lbs / kg)435,000 / 197,313446,400 / 202,484479,800 / 217,634429,900 / 195,000489,800 / 222,170
Tender Water Capacity (gals / ML)8000 / 30.308000 / 30.3010,000 / 37.888000 / 30.3010,000 / 37.88
Tender Fuel Capacity (oil/coal) (gals/tons / ML/MT)15 / 13.6015 / 13.6018 / 16.4015 / 13.6018 / 16.40
Minimum weight of rail (calculated) (lb/yd)9192919294
Geometry Relating to Tractive Effort
Driver Diameter (in / mm)63 / 160063 / 160063 / 160063 / 160063 / 1600
Boiler Pressure (psi / kPa)185 / 12.80187 / 12.90187 / 12.90185 / 12.80187 / 12.90
High Pressure Cylinders (dia x stroke) (in / mm)27" x 30" / 686x76227" x 30" / 686x76227" x 30" / 686x76227" x 30" / 686x76227" x 30" / 686x762
Tractive Effort (lbs / kg)54,588 / 24760.7355,178 / 25028.3555,178 / 25028.3554,588 / 24760.7355,178 / 25028.35
Factor of Adhesion (Weight on Drivers/Tractive Effort) 3.99 4.00 3.95 4.06 4.08
Heating Ability
Firebox Area (sq ft / m2)345 / 32.06272 / 25.28316 / 29.37300 / 27.88397 / 36.90
Grate Area (sq ft / m2)70 / 6.5170 / 6.5170 / 6.5168 / 6.3268 / 6.32
Evaporative Heating Surface (sq ft / m2)4180 / 388.484105 / 381.514149 / 385.593856 / 358.363856 / 358.36
Superheating Surface (sq ft / m2)880 / 81.78880 / 81.78880 / 81.78798 / 74.16798 / 74.16
Combined Heating Surface (sq ft / m2)5060 / 470.264985 / 463.295029 / 467.374654 / 432.524654 / 432.52
Evaporative Heating Surface/Cylinder Volume210.26206.48208.70193.96193.96
Computations Relating to Power Output (More Information)
Robert LeMassena's Power Computation12,95013,09013,09012,58012,716
Same as above plus superheater percentage15,15215,44615,31514,71914,878
Same as above but substitute firebox area for grate area74,67560,02069,13864,93586,860
Power L113,50813,22013,48112,25112,862
Power MT546.42528.23545.33487.74503.66

Specifications by Steve Llanso of Sweat House Media
ClassL3
Locobase ID6127
RailroadChicago Great Western (CGW)
CountryUSA
Whyte2-8-2
Number in Class10
Road Numbers750-759
GaugeStd
Number Built10
BuilderBaldwin
Year1918
Valve GearWalschaert
Locomotive Length and Weight
Driver Wheelbase (ft / m)16 / 4.88
Engine Wheelbase (ft / m)36.08 / 11
Ratio of driving wheelbase to overall engine wheebase 0.44
Overall Wheelbase (engine & tender) (ft / m)71.37 / 21.75
Axle Loading (Maximum Weight per Axle) (lbs / kg)
Weight on Drivers (lbs / kg)220,000 / 99,790
Engine Weight (lbs / kg)292,000 / 132,449
Tender Loaded Weight (lbs / kg)189,400 / 85,910
Total Engine and Tender Weight (lbs / kg)481,400 / 218,359
Tender Water Capacity (gals / ML)10,000 / 37.88
Tender Fuel Capacity (oil/coal) (gals/tons / ML/MT)18 / 16.40
Minimum weight of rail (calculated) (lb/yd)92
Geometry Relating to Tractive Effort
Driver Diameter (in / mm)63 / 1600
Boiler Pressure (psi / kPa)200 / 13.80
High Pressure Cylinders (dia x stroke) (in / mm)26" x 30" / 660x762
Tractive Effort (lbs / kg)54,724 / 24822.42
Factor of Adhesion (Weight on Drivers/Tractive Effort) 4.02
Heating Ability
Firebox Area (sq ft / m2)356 / 33.09
Grate Area (sq ft / m2)66.70 / 6.20
Evaporative Heating Surface (sq ft / m2)3808 / 353.90
Superheating Surface (sq ft / m2)882 / 81.97
Combined Heating Surface (sq ft / m2)4690 / 435.87
Evaporative Heating Surface/Cylinder Volume206.56
Computations Relating to Power Output (More Information)
Robert LeMassena's Power Computation13,340
Same as above plus superheater percentage15,875
Same as above but substitute firebox area for grate area84,728
Power L115,408
Power MT617.61

Photos

Reference