This class was originally delivered with 20" x 24" cylinders. Even with the longer stroke, the cylinder proportions were still at odds with most Twelve-wheelers. Like virtually all Great Northern locomotives, however, these had Belpaire fireboxes.
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. At the time of its sale, the railroad encompassed 3,879 miles of track.
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.
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 small drivers meant these would always perform in 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.
At least one was superheated; see Locobase 8817.
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", 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.
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.
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 2866-28677 in December 1897 and 2999-3004 in July 1898.
Designed by JO Pattee, superintendent of Motive Power for the Great Northern. 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 of arch pipes.) Still, the 16-in 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 19x32" cylinders.
|Specifications by Steve Llanso|
|Railroad||Saint Paul, Minneapolis & Manitoba(GN)||Eastern Railway of Minnesota (GN)||Great Northern (GN)||Great Northern (GN)||Great Northern (GN)||Montana Central (GN)|
|Road Numbers||400-415||700-719||720-769||722||770-779||100-107 / 800-807|
|Locomotive Length and Weight|
|Ratio of driving wheelbase to overall engine wheebase||0.61||0.59||0.68||0.68||0.67||0.59|
|Overall Wheelbase (engine & tender)||52.08'||53.83'||52.60'||54.08'||53.83'||54.25'|
|Axle Loading (Maximum Weight per Axle)||0||35500 lbs||37000 lbs||37000 lbs||37500 lbs|
|Weight on Drivers||136025 lbs||142000 lbs||148000 lbs||148000 lbs||150000 lbs||172000 lbs|
|Engine Weight||155975 lbs||176000 lbs||182000 lbs||182000 lbs||182000 lbs||212750 lbs|
|Tender Light Weight||82012 lbs||90000 lbs||102000 lbs||126800 lbs||107000 lbs||96000 lbs|
|Total Engine and Tender Weight||237987 lbs||266000 lbs||284000 lbs||308800 lbs||289000 lbs||308750 lbs|
|Tender Water Capacity||4752 gals||5000 gals||5000 gals||6000 gals||5000 gals||4500 gals|
|Tender Fuel Capacity (oil/coal)||8.8 tons||8 tons||8 tons||4000 gals||8 tons||10 tons|
|Minimum weight of rail (calculated) on which locomotive could run||57 lb/yard||59 lb/yard||62 lb/yard||62 lb/yard||63 lb/yard||72 lb/yard|
|Geometry Relating to Tractive Effort|
|Boiler Pressure||180 psi||200 psi||180 psi||160 psi||180 psi||210 psi|
|Cylinders (dia x stroke)||20" x 26"||19" x 32"||19" x 32"||23.5" x 32"||19" x 32"||21" x 34"|
|Tractive Effort||28931 lbs||35706 lbs||32136 lbs||43698 lbs||32136 lbs||48662 lbs|
|Factor of Adhesion (Weight on Drivers/Tractive Effort)||4.70||3.98||4.61||3.39||4.67||3.53|
|Firebox Area||192 sq. ft||219.50 sq. ft||198 sq. ft||198 sq. ft||228 sq. ft||235 sq. ft|
|Grate Area||31.63 sq. ft||35.20 sq. ft||34.18 sq. ft||34.18 sq. ft||35.20 sq. ft||34 sq. ft|
|Evaporative Heating Surface||2226 sq. ft||2863 sq. ft||2493 sq. ft||2024 sq. ft||3080 sq. ft||3280 sq. ft|
|Superheating Surface||375 sq. ft|
|Combined Heating Surface||2226 sq. ft||2863 sq. ft||2493 sq. ft||2399 sq. ft||3080 sq. ft||3280 sq. ft|
|Evaporative Heating Surface/Cylinder Volume||235.46||272.64||237.40||125.99||293.30||240.65|
|Computations Relating to Power Output (More Information)|
|Robert LeMassena's Power Computation||5693||7040||6152||5469||6336||7140|
|Same as above plus superheater percentage||5693||7040||6152||6344||6336||7140|
|Same as above but substitute firebox area for grate area||34560||43900||35640||36749||41040||49350|