DONNER SUMMIT, Calif. (KTXL) — Since rail lines were laid across the Sierra Nevada, a battle has ensued between the railroad companies and the seemingly never-ending snow, but a few trusted and hard-working tools have been able to power through these walls of glistening white, allowing for trains to operate even after heavy snowfall.
When Theodore Judah surveyed Donner Summit as the best route for the Central Pacific’s portion of the Transcontinental Railroad, he underestimated the snowfall in the Sierra Nevada.
As the snow began to pile up and rail traffic was halted, the wedge or “bucker” plow was used to clear the light snowfall of the winter.
Pushed by four to 14 locomotives, this towering wooden wedge-shaped plow would lift the snow off the track and force it to the sides in low and wide banks.
When heavy snowfall brought levels to more than 13 feet, the wedge plow was not effective and today they are used as a low-maintenance option for clearing smaller snow drifts from the tracks.
The wedge plow was the primary means to clear snow until the late 1880s when Orange Jull expanded on the ideas of Canadian dentist J.W. Elliot for a rotary plow and hired the Leslie Brothers to build a full-size prototype.
Besides the monumental scale of these plows, the large fan at the front of the plow was the distinguishing and evolutionary feature of this plow.
As the train plows forward, the snow is cut up by the blades of the fan and then sent through a channel behind the blades, where a chute then ejects the snow to either the left or right side of the plow.
Rotary plows are primarily used when snow drifts are too tall or dense for wedge plows to get through.
Because the fan of the plow breaks up the snow, the locomotive can move at a slow speed, providing a much safer way of removing snow than with the front plow that was used before, which required more momentum in order to push the snow out of the way, which could also cause a derailment.
A train using these fan plows usually consists of two rotary plows and three locomotives with the rotary ends of each plow facing outwards and the locomotives placed between them.
This allows for the train to clear a path in one direction, and if snow falls again, the rotary plow at the other end can once again clear the tracks on the return trip.
Also, the train is able to clear tracks running in opposite directions without the need of turning the train around or moving the plow to the opposite end of the train.
Rotary plows were most recently used in the Sierra in 2017, when 13 feet of snow built up along 14 miles of track near Donner Pass, according to Union Pacific.
Today, Union Pacific operates three rotary snow plows that were built in the 1920s and were updated to diesel-electric engines in 1952.
In 2012, one of the rotary plows was given a series of upgrades that increased productivity, reliability and power.
In 2014, rotary snowplow SPMW 7221 was placed on display outside of Union Pacific’s J.R. Davis Yard in Roseville, as the city served as the storage location for then-Southern Pacific’s rotary plows.
“All rotaries for the Sierras ran out of Roseville,” said Bill Lynch, retired Southern Pacific superintendent in an interview with Union Pacific. “They were sometimes called War Wagons — going to war against Mother Nature. If there was any one place on the railroad that this belongs, it’s right here.”
Although the rotary plows made easy work of clearing through the “Donner Summit Cement,” it would leave high snow banks along the sides of the track that could collapse back onto the tracks, potentially when another train is passing through.
To combat this shortcoming, Union Pacific uses what are called spreaders and flangers.
Spreaders have a movable wing at the front that is able to extend 20 feet left or right, allowing it to push the snow farther from the tracks than a rotary plow can. Flangers are used to clear snow from under the railroad tracks.
The spreaders are more commonly used and are stationed in Truckee.