2-8-8-4 — The Yellowstone Survivors

After building my web page on the Bigboy Survivors, I recalled that I had seen some locomotives up on the Minnesota Iron Range that looked like Bigboys, but they were not on the list of survivors. After doing some research, I found out that these engines were just slightly older and smaller than the Bigboys. To start with, the wheel configuration is 2-8-8-4, where as the Bigboy is 4-8-8-4. That is, 2 small wheels at the front to steer the locomotive, 8 large driver wheels, a second group of 8 larger driver wheels, and 4 smaller wheels to support the weight of the firebox and cab. This locomotive type is called the Yellowstone. Like the Bigboy, the Yellowstone is also articulated, which means that the front 10 wheels are on a frame that pivots independently of the body of the steam engine. This allows it to negotiate curves in the railroad track despite its long chassis length.

While the Bigboys were built during WWII and were scrapped after only 5 to 10 years of service, the Yellowstones were built in the late 1920’s and 1930’s and were in service into the early 1960’s. 72 of these monsters were built, and were operated by the Northern Pacific, Southern Pacific, Baltimore & Ohio, and the DM&IR (Duluth Missabe & Iron Range). The Yellowstone is just a few feet shorter than a Bigboy at 128 feet, and they are 63,000 lbs lighter than a Bigboy at 699,700 lbs. Despite weighing less, the Yellowstone had more weight on the driver wheels, and had a slightly higher total tractive force than the Bigboy (140,000 pounds of force, versus 135,000 pounds for the Bigboy).

Pulling power was really important for the DM&IR. These locomotives hauled massive loads of iron ore out of the Minnesota Iron Range. Just as important was the ability to stop...because the Duluth harbor was at the bottom of an 800 foot ridge of bluffs, and the trip downhill was down the steepest railroad incline in the US that is in regular usage. Old timers say that just pulling empty cars up this 2.2% grade out of Duluth took everything that the Yellowstone could muster.

The Yellowstone locomotives, and the men who kept them running, were a key factor in winning World War II. The iron that was hauled out of the Minnesota Iron Range built the guns, ships, and tanks that overwhelmed the NAZI war machine. It is a shame that only 3 survive.

Here is a link to an excellent site on Yellowstone locomotives... www.steamlocomotive.com/yellowstone.