Eastern Railway of Minnesota / Great Northern / Montana Central / Saint Paul, Minneapolis & Manitoba 4-8-0 "Mastodon" Locomotives in the USA


Class Details by Steve Llanso of Sweat House Media

Class Class 38/G-1 (Locobase 8565)

Data from M Grille & MH Falconnette, Les Chemins de Fer a L'Exposition de Chicago, (Paris, France: E Bernard et Cie, 1894), p 44-47, supplemented by GN 1916 Locomotive Diagrams supplied in May 2005 by Allen Stanley from his extensive Rail Data Exchange. See also "Twelve-Wheeler Freight Locomotive- Great Northern Railway", Railway Review, Volume 32, No 8 (20 February 1892), pp. 112-113, diagrams on Supplement, between pp. 118-119. (Thanks to Chris Hohl for his 6 December 2018 email noting several corrections and additions.)

Brooks builder info from B.Rumary, 25 Kingscombe, Gurney Slade, Radstock, BA3 4TH, ENGLAND and Jeremy Lambert as supplied by Allen Stanley in March 2004.Works numbers were 1972-1981 in October 1891, 1998-2000 in November, 2001-2002 in December and a exhibition engine for the Columbian Exposition in Chicago as works number 2261 in March 1893.

The first ten locomotives in this class were originally delivered with 20" x 24" (509 mm x 610 mm) cylinders, but were soon rebuilt to match the last six that rolled off the Dunkirk floor in November 1891; five of these were delivered to the Montana Central. Even with the longer stroke, the cylinder proportions were still at odds with most Twelve-wheelers.

Hohl noted that some of the class were fitted with wagon top boilers. These were 600-604. Beginning with 605, the remainder, like virtually all Great Northern locomotives, mounted square-shouldered Belpaire fireboxes. (The first five Belpaires were ordered at the same time as the wagon tops, likely as a means to compare the two fireboxes. On the other hand, all fifteen locomotives were built over a three-month period.) Eventually only 603 would retain the wagon top as late as 1946.

Chris Hohl's email noted the incorrect grate area and firebox area, which had come from the French source shown above. Later diagrams show the values now entered in the specs. Between 1916 and 1929, the original working pressure shown in the specs was reduced to 160 psi (11 bar). In all but the 609, the reduced setting lowered starting tractive effort to 25,720 lb (11,666 kg or 114.41 kN). By 1916, only 609 still used the 20 x 24" cylinder with which she was fitted when delivered. The shorter stroke decreased starting tractive effort at 180 psi to 26,710 lb (12,115 kg or 118.81 kN and 23,738 lb (10,767 kg or 105.6 kN).

The StPM&M was organized in May 1879 as an amalgamation of the Saint Paul & Pacific, Morehead & Barnesville, and the Red River Valley. At that point, the Great Northern leased the railroad (extending it in 1890), but the StPM&M held on to its separate identity until the line was sold to the GN in 1907.

When these fifteen Twelve-wheelers arrived, the StPM&M comprised 2,775 miles (4,468 km). At the time of its sale, the railroad encompassed 3,879 miles (6,245 km) of track.

The GN kept them in service for another twenty years or so.

All five ex-Montana Central engines were scrapped in 600-602, 604-605, 608, 610-611, 614-615 were scrapped in the late 1920s. 609 followed in September 1932, 607 in October 1941 and 613 in December, and 603, 607, and 612 in 1947.


Class G-2 (Locobase 8847)

Data from GN 1916 locomotive diagram book supplied in May 2005 by Allen Stanley from his extensive Rail Data Exchange. Brooks produced these in June (2973-2975), July (2982-2990), August (3045-3048), and September (3049-3052).

Like all GN 4-8-0s, the G-2s had small drivers and Belpaire fireboxes. Very shortly after the ERofM had taken delivery of this class, the railroad was absorbed by the Great Northern. Except for the 701, which was converted to a 2-8-0 and redesignated F-3, these Twelve-wheelers remained essentially unchanged and had 30-year careers.


Class G-3 (Locobase 8816)

Data from GN 4 1946 Locomotive Diagrams supplied in May 2005 by Allen Stanley from his extensive Rail Data Exchange. Works numbers were 5370-5373 in April 1899; 5379-5385, 5399-5405 in July; 5407-5409, 5416-5419 in August; 5542-5543, 5546, 5548-5549, 5551, 5553-5554, 5556-5558 in May 1900; 5559, 5561-5562, 5564-5574 in June.

This large order of Twelve-wheelers came at the height of that wheel arrangement's popularity. As with most GN locomotives, this design had the signature Belpaire firebox. The long stroke and small drivers meant these would always perform slow-freight duties, but they were serviceable enough for 20 to have been retained through World War II. Some of the class had bigger tenders carrying 15 tons of coal.

Two were superheated; see Locobase 8817.

736 was sold to the Pacific & Eastern in March 1910 as their 101, later 4. In December 1917, the Spokane Valley & Northern bought the 4. 757 was sold in September 1944 to Truax Traer Coal Company of North Dakota.


Class G-3-S (Locobase 8817)

Data from GN 4 1946 Locomotive Diagrams supplied in May 2005 by Allen Stanley from his extensive Rail Data Exchange.

Among the 50-odd G-3 Twelve-wheelers were a couple that were later superheated. The H&D superheater is a rarity - notice the small bore of the flues. The gain in effective steam was needed for the railroad increased the cylinder diameter by 4 1/2" (114 mm), while reducing boiler pressure to an anemic 160 psi. 722 had 189 2" tubes as shown while 734 had 185 and a total evaporative heating surface of 1,980 sq ft (183.95 sq m).


Class G-4 (Locobase 8818)

Data from GN 4 1946 Locomotive Diagrams supplied in May 2005 by Allen Stanley from his extensive Rail Data Exchange.

The large Rogers order for 50 Twelve-wheelers in 1899-1900 (see Locobase 8816) was followed by this decade from the Dunkirk, New York builder who had made a specialty out of large engines in this wheel arrangement. The boiler certainly was large and must have taxed the relatively small grate in the Belpaire firebox.


Class G-5 (Locobase 191)

Data from Catalogue Descriptive of Simple and Compound Locomotives built by Brooks Locomotive Works, Dunkirk, NY (Buffalo, NY: Matthew-Northrup Company, 1899). See also "Heavy Twelve-wheel Locomotives for the Great Northern", Railroad Gazette, Volume XXX, No 1 (7 Jan 1898), pp. 3-5; "106-Ton Twelve Wheel Locomotive; Great Northern Railway," Engineering News, Volume XXXIX, No. 15 (14 April 1898), pp. 236-237; Charles McShane (1899). (Many thanks to Chris Hohl for his 22 September 2017 email reporting unlikely boiler pressure values for 177 entries. A Locobase macro caused the error .)Works numbers were 2866-28677 in December 1897 and 2999-3004 in July 1898.

Brooks builder info from B.Rumary, 25 Kingscombe, Gurney Slade, Radstock, BA3 4TH, ENGLAND and Jeremy Lambert as supplied by Allen Stanley in March 2004.

Designed by JO Pattee, superintendent of Motive Power for the Great Northern for its subsidiary MC.. Not a very attractive engine because of its high Improved Belpaire (aka Player-Belpaire) boiler with its inelegant square-shouldered firebox. (The firebox contained 26 sq ft/2.4 sq m of arch pipes.) Still, the 16-in (406 mm) diameter piston valves are worthy of notice, as large, McShane noted, as the pistons of many locomotives then in service. Indeed, much about the engine, including a 34-in piston stroke and other "brobdignagian" dimensions, made it a conversation piece of the time.

MC #103 was Brooks's 3,000th engine. When the Great Northern absorbed the Montana Central in 1902, this class was renumbered 800-807. One -- 806 -- was turned into a 2-8-0 in 1905 and redesignated F-10. All were scrapped in the late 1920s - early 1930s.

Two later classes -- G-3 (50 from Rogers) and G-4 (10 from Brooks for the Eastern Railway of Minnesota) were similar, but had 19 x 32" cylinders.

Principal Dimensions by Steve Llanso of Sweat House Media
ClassClass 38/G-1G-2G-3G-3-SG-4
Locobase ID8565 8847 8816 8817 8818
RailroadSaint Paul, Minneapolis & Manitoba (GN)Eastern Railway of Minnesota (GN)Great Northern (GN)Great Northern (GN)Great Northern (GN)
CountryUSAUSAUSAUSAUSA
Whyte4-8-04-8-04-8-04-8-04-8-0
Number in Class162050210
Road Numbers400-409, MC 50-54/600-615700-719720-769722, 734770-779
GaugeStdStdStdStdStd
Number Built16205010
BuilderBrooksBrooksRogersGNBrooks
Year1891189818991900
Valve GearStephensonStephensonStephensonStephensonStephenson
Locomotive Length and Weight
Driver Wheelbase (ft / m)15.50 / 4.7215.33 / 4.6715.58 / 4.7515.58 / 4.7515.33 / 4.67
Engine Wheelbase (ft / m)25.25 / 7.7026.17 / 7.9823.08 / 7.0323.08 / 7.0322.83 / 6.96
Ratio of driving wheelbase to overall engine wheebase 0.61 0.59 0.68 0.68 0.67
Overall Wheelbase (engine & tender) (ft / m)52.08 / 15.8753.83 / 16.4152.60 / 16.0354.08 / 16.4853.83 / 16.41
Axle Loading (Maximum Weight per Axle) (lbs / kg)35,500 / 16,10337,000 / 16,78337,000 / 16,78337,500 / 17,010
Weight on Drivers (lbs / kg)132,000 / 59,874142,000 / 64,410148,000 / 67,132148,000 / 67,132150,000 / 68,039
Engine Weight (lbs / kg)156,000 / 70,760176,000 / 79,832182,000 / 82,554182,000 / 82,554182,000 / 82,554
Tender Loaded Weight (lbs / kg)82,012 / 37,20090,000 / 40,823102,000 / 46,266126,800 / 57,516107,000 / 48,534
Total Engine and Tender Weight (lbs / kg)238,012 / 107,960266,000 / 120,655284,000 / 128,820308,800 / 140,070289,000 / 131,088
Tender Water Capacity (gals / ML)4752 / 185000 / 18.945000 / 18.946000 / 22.735000 / 18.94
Tender Fuel Capacity (oil/coal) (gals/tons / ML/MT) 8.80 / 88 / 7.308 / 7.304000 / 15.208 / 7.30
Minimum weight of rail (calculated) (lb/yd / kg/m)55 / 27.5059 / 29.5062 / 3162 / 3163 / 31.50
Geometry Relating to Tractive Effort
Driver Diameter (in / mm)55 / 139755 / 139755 / 139755 / 139755 / 1397
Boiler Pressure (psi / kPa)160 / 11200 / 13.80180 / 12.40160 / 11180 / 12.40
High Pressure Cylinders (dia x stroke) (in / mm)20" x 24" / 508x61019" x 32" / 483x81319" x 32" / 483x81323.5" x 32" / 597x81319" x 32" / 483x813
Tractive Effort (lbs / kg)23,738 / 10767.3935,706 / 16195.9932,136 / 14576.6643,698 / 19821.1032,136 / 14576.66
Factor of Adhesion (Weight on Drivers/Tractive Effort) 5.56 3.98 4.61 3.39 4.67
Heating Ability
Firebox Area (sq ft / m2)182.10 / 16.92219.50 / 20.40198 / 18.40198 / 18.40228 / 21.19
Grate Area (sq ft / m2)24.60 / 2.2935.20 / 3.2734.18 / 3.1834.18 / 3.1835.20 / 3.27
Evaporative Heating Surface (sq ft / m2)2208 / 205.132863 / 266.082493 / 231.692024 / 188.103080 / 286.25
Superheating Surface (sq ft / m2)375 / 34.85
Combined Heating Surface (sq ft / m2)2208 / 205.132863 / 266.082493 / 231.692399 / 222.953080 / 286.25
Evaporative Heating Surface/Cylinder Volume253.02272.64237.40125.99293.30
Computations Relating to Power Output (More Information)
Robert LeMassena's Power Computation39367040615254696336
Same as above plus superheater percentage39367040615263446336
Same as above but substitute firebox area for grate area29,13643,90035,64036,74941,040
Power L152416914547358336631
Power MT350.13429.37326.11347.56389.84

Principal Dimensions by Steve Llanso of Sweat House Media
ClassG-5
Locobase ID191
RailroadMontana Central (GN)
CountryUSA
Whyte4-8-0
Number in Class8
Road Numbers100-107/800-807
GaugeStd
Number Built8
BuilderBrooks
Year1897
Valve GearStephenson
Locomotive Length and Weight
Driver Wheelbase (ft / m)15.83 / 4.82
Engine Wheelbase (ft / m)26.67 / 8.13
Ratio of driving wheelbase to overall engine wheebase 0.59
Overall Wheelbase (engine & tender) (ft / m)54.25 / 16.54
Axle Loading (Maximum Weight per Axle) (lbs / kg)
Weight on Drivers (lbs / kg)172,000 / 78,018
Engine Weight (lbs / kg)212,750 / 96,502
Tender Loaded Weight (lbs / kg)96,000 / 43,545
Total Engine and Tender Weight (lbs / kg)308,750 / 140,047
Tender Water Capacity (gals / ML)4500 / 17.05
Tender Fuel Capacity (oil/coal) (gals/tons / ML/MT)10 / 9.10
Minimum weight of rail (calculated) (lb/yd / kg/m)72 / 36
Geometry Relating to Tractive Effort
Driver Diameter (in / mm)55 / 1397
Boiler Pressure (psi / kPa)210 / 14.50
High Pressure Cylinders (dia x stroke) (in / mm)21" x 34" / 533x864
Tractive Effort (lbs / kg)48,662 / 22072.74
Factor of Adhesion (Weight on Drivers/Tractive Effort) 3.53
Heating Ability
Firebox Area (sq ft / m2)235 / 21.84
Grate Area (sq ft / m2)34 / 3.16
Evaporative Heating Surface (sq ft / m2)3280 / 304.83
Superheating Surface (sq ft / m2)
Combined Heating Surface (sq ft / m2)3280 / 304.83
Evaporative Heating Surface/Cylinder Volume240.65
Computations Relating to Power Output (More Information)
Robert LeMassena's Power Computation7140
Same as above plus superheater percentage7140
Same as above but substitute firebox area for grate area49,350
Power L16292
Power MT322.59

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