This blog entry has taken me the better part of four months to compile & compose, as there isn't very much information on this locomotive class available on the internet. I've only encountered bits & pieces, and a few scraps of information here & there.
Great Northern's Odd-ball locomotive the M Class 2-6-8-0
While the Great Northern's Motive Power Department wasn't a major innovator in design, it excelled in converting older units to a newer design by using parts removed from the older locomotives. This recycling of locomotives led to the design & development of GN's Mikado class (the O-5, O-6 & O-8's which were built from GN's own roster of L Class & M Class locomotives).
The experimental M class 2-6-8-0 is one of the earliest examples, and one of the few which was actually built by the GN was #2000. It was first built as an F-8 consolidation 2-8-0 #1254, by Baldwin Locomotive works in Dec 1907. On Jan 15, 1910 it was rolled out of the Dale St. Shops (Minneapolis/St. Paul, Minnesota) as GN's first #2000. Built using a boiler extension & front engine from Baldwin. The design produced a lone orphan Mallet and was by 1926 renumbered to 1999. It was once again rebuilt to a C-4 0-8-0 #870 at the Dale St. Shops. It also was not well photographed, I've only seen 3 images of the locomotive.
The GN late in 1910 ordered 35 Baldwin constructed M-1, 2-6-8-0's.
The first batch of M-2's #1950-1959 were delivered on the 9 Nov. & Dec 1909. All were equipped with Walschaert valve gear, and sat on 55" drivers. With a boiler pressure of 200 psi. They were similar to the Southern L. But GN's were heavier, had smaller drivers & boilers, and all were delivered with GN's trademark Belpaire fireboxes.
http://www.gngoat.org/gn_1957.jpg at Summit, Mt. 1923.
https://en.wikipedia.org/wiki/2-6-8-0 #1951 at Skykomish, Wa. 1924.
The second batch #1960-1984 were built in June of 1910. As delivered they were all M-1 compound engines, and were simplified in 1926-1928 by the Great Northern, when they were reclassed as M-2's.
http://www.northeast.railfan.net/images/gn1980.jpg
http://www.northeast.railfan.net/images/gn1981.jpg
NOTE: #2001 & #2022 are NOT Class M locomotives, they are Class N's and are 2-8-8-0's.
Engine #'s 1950-1971 were the conversion base which were used to build the GN 69" drivered O-7 Mikados. #3375-3396.
The M's were a slow-speed locomotive, at any speed over 25 MPH, their weight was hard on the engine and track. Above that speed they vibrated with a lot of noise, and the gauges would bounce. The roughness of the ride may have been due to the large counterweights on the last driver axle, and lack of a trailing truck. Which meant that during a reverse move the M met every rail joint and switch point head on, which changed the angle of direction, with a positive lurch of the locomotive. The M's saw service mostly between Butte & Great Falls, Montana.
The GN & the Alabama Great Southern predecessor of the Southern Railway, were the sole users of this wheel arrangement. The AGS only purchased one of these #300 later 6399, which was classed as a J. http://railga.com/ags.html
After about 4 years of what must have been unsatisfying operation, the engine went over to the Chicago, New Orleans & Texas for three years, and then to the Southern itself. The Southern ran it for another 18 years before scrapping it in 1935. The Southern purchased 2 #4002 & 4003 and were classed as L's. Image: http://railga.com/srmallet4002.jpg
Alabama Great Southern Great Northern Southern Railway
Class J M-2 (simple) L
Yr. built 1909 1926 1911
Weight on Drivers 332,700 Lbs. 384,000 Lbs. 332,700 Lbs.
{Total Engine &
Tender Weight} 535,000 Lbs. 583,000 Lbs. 525,500 Lbs.
Tractive Effort 71,780 Lbs. 107,620 Lbs. 71,780 Lbs.
Charlie
