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GN O-1 Class 2-8-2

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O-1 Class 2-8-2 General Data


Between 8/1911 and 2/1919



Engine weight:

3000-3069: 280,000 lbs.

3070-3144: 306,000 lbs.


Baldwin Locomotive Works

Driver diameter:


Weight on drivers:

3000-3069: 220,000 lbs.

3070-3144: 229,000 lbs.

Number series:

3000 - 3144

Boiler pressure:

Design: 210 psi.

Operating: 180 psi.

Tractive effort:

60,930 lbs.

Only one of the 145 O-1's built, has been preserved. Being the last survivor of its class, engine #3059 is also the only surviving example of the many 2-8-2's the Great Northern Railway used as the backbone for its freight service.


The O-1 class came to be when Baldwin Great Northern Railway Locomotive Works was contracted by Great Northern to built GN's first 2-8-2 type. In 1911 construction was started on the first twenty O-1 Mikado's, numbered 3000 through 3019. These were the first of what would eventually become the largest class of 2-8-2's on the GN, with a total of 145 O-1's delivered by 1919.


The O-1 engines came equipped with a Belpaire type boiler, similar to those used on the L-class 2-6-6-2's. Tapering from a 82" diameter at the front, to a 89" diameter at the dome ring, the boiler was constructed for a design pressure of 210 psi, and an operating pressure of 180 psi. The boiler had a firebox measuring 117" long by 96" wide, designed to burn coal.


A Walschaert type valve gear transmitted power from the 28" diameter by 32"stroke pistons to the drivers, which were 63" in diameter, all of them flanged. 


In 1913 Great Northern went back to Baldwin for an additional 50 copies, numbered 3020Baldwin Locomotive Works through 3069. Compared to the initial order, little  changes were made except for the number and size of boiler tubes. An exception were engines 3020 and 3021, which were built as oil-burners.


By 1916 GN was ready to order more O-1's and received 25, numbered 3070 through 3094. These were heavier, weighing in at 306,500 lbs, with a weight on drivers of 229,000 lbs. The boiler was also slightly changed, with the dome ring longer and the sandbox moved forward. These engines came equipped with Street Stokers and Franklin grate shakers.


GN O-1 2-8-2 #3020 Location unknown. (Howard Davis)

Finally, from 1917 through 1919, the fourth and last group of 50 O-1s arrived (#3095-3144). The only difference this time being a larger sandbox. Engines 3140 through 3144 were slightly different as these came equipped with a Southern type valve gear.


All O-1s came with tenders having a capacity of 8,000 gallons of water and 13 tons of coal (4,500 gallons of oil on engines 3020 and 3021). This capacity proved insufficient and over the years, many tenders were modified to larger capacities. 


During their lives on the GN, many improvements were made to these engines. Some were temporarily equipped with 11,000 to 12,200 lbs. tractive effort boosters, others received feedwater heaters, exhaust steam injectors or superheaters. Engines 3140-3144 lost their Southern type valve gear, as they were replaced with the class-standard Walschaert type valve gear. Later in their careers many O-1's found their tenders exchanged with tender types from other classes.


SP&S logoThe O-1 2-8-2's were assigned system wide. The class stayed intact until 1925 when the first O-1's were sold to the Spokane, Portland & Seattle. Engines 3023, 3024, 3026, 3028, 3029, 3039, 3043, 3064, 3099, 3108, 3121, 3122 and 3134 were sold to the SP&S between 1925 and 1944. The first GN O-1 to be stricken from the roster was 3113 after being wrecked in 1946. The only other wreck in this class was O-1 3128 in 1949. The rest of the class started to be retired in the 1950's, with the last 14 retired in 1957 and 1958, eventually ending up being scrapped in 1962 and 1963.


Only one O-1, #3059, survives. She was put on public display at the Williston, North Dakota depot on August 2, 1958. Number 3059 is the only remaining representative of the mighty 2-8-2's the Great Northern relied on so heavily.


GN O-1 Class 2-8-2 3059 on public display at Williston, ND

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Click for map to #3059

Photos taken July 22, 2002


Sources and additional reading:

GNRHS Reference Sheet #12: Great Northern Class O-1, 2-8-2

GNRHS Reference Sheet #22: Great Northern Class O-1, 2-8-2 Part II

Railroad History 143 - Great Northern Railway published by the RLHS

Steamlocomotive.com: Great Northern Mikados webpage