"Rotary Snow Plows, Union Pacific Style."

This page was last updated on February 5, 2014.

(Taken from Union Pacific INFO magazine, Volume 4, Number 2, January 1972)

Editor's Note: This article concludes a two-part series on the development and use of rotary snow plows. We would like to invite our readers' comments on this material. If you have any suggections for future articles, please let us knowwe're always looking for new ideas. .....

With the passing of the steam locomotive, the fuel and water facilities used with steam power were also phased out. Without these facilities, the steam-driven rotary snow plow was found in somewhat the same situation as the great dinosaurs when their swamps dried up. Extinction was just a question of time.

Immediately following the historic 1949 blizzard engineering studies were started to develop a diesel dieselelectric rotary snow plow. The design concepts of this rotary plow were to utilize as much as possible the components in use on dieselelectric locomotives, and to have at least as much power as the newest, largest steam-driven rotaries constructed in 1949. It was also desired to make the plow self-controlled so that the plow engineer would have full control of both the rotary plow wheel and the diesel pusher units. This would simplify operation and eliminate the problem of coordinating the operations of plow and pusher engineers.

As a result of these, a new design rotary snow plow, road number 900080, was constructed in the Omaha shops during 1958. Stationary load testing was completed during November, and the plow moved to Pocatello, for road testing.

On March 3, 1959, the new plow made its initial road plowing trip, opening up the 56-mile-line of branch track between Ashton, Idaho and West Yellowstone, Montana in twelve hours. Removal of the snow which accumulates during the winter months is a major operation. This particular winter the snow varied from 2 to 8 feet in depth. Forward speed of the plow during the operation varied from 2 to 14 mph. A single GP-9 pusher unit was used throughout the 56-mile run, except for 7 miles of one to two per cent grade through Reas Pass, where it was necessary to cut in a second GP-9. During the trip the rotary engine operated in maximum throttle position for 5 hours 39 minutes. Total time for main track plowing was 8 hours 12 minutes. The remainder of the time was consumed in digging out switches, plowing sidings and wyes, reversing the rotary wheel to cast on opposite side of track, etc. There was no mechanical or electrical trouble. The plow operated with much less vibration and noise then a steam-powered plow. The speed of this operation was phenomenal-had the steamdriven Lima-Hamilton built rotary been used it would have required 32 to 40 hours of plowing.

Diesel-electric rotary 900080 has been used seven times to open up the Yellowstone Branch after a winter's accumulation of snow. This branch has proven to be an excellent test site. Had it not been for this branch, testing would have been impossible because of a succession of mild winters. Each test trip has developed refinements which have been added to the basic design.

[photo caption] The 12-foot diameter of the rotary wheel on 900081 is apparent when compared to the height of the men working on the blades.

The tremendous development which has taken place in freight car design has been reflected in snow fighting equipment. Longer and wider cars require a wider cut on curves to provide clearance at the mid point of the car. Since rotary wheel housings were already close to the maximum clearance, it was not possible to make the wheel housing wider. To obtain a wider cut on curves the plow housing of the 900080 was equipped with hydraulically actuated wings which increase the width of cut from 12'6" to 14'0" .

The successful operation of the 900080 and the wealth of test data accumulated between 1958 and 1965 provided the impetus for design and construction of a second diesel-electric plow. The second plow was to be essentially the same as the 900080, except larger and more powerful. Wheel diameter was to be increased from 11 '2112" to 12'0" and diesel engine power raised from 1800 to 2500 h.p.

The second diesel rotary, road number 900081, designed and constructed by Union Pacific, was completed and stationary tested at Omaha in November of 1966. Its design and construction incorporated many special features. In order to reduce weight as much as possible, maximum use was made of high strength alloy steels. Special welding techniques were used for these materials and every weld was supervised and inspected. Only in UP's own shops could such insistence on welding perfection be satisfied. It is questionable whether or not this plow could have been built anywhere else.

Operation of both 900080 and 900081 was so successful that a third diesel-electric plow was designed and built in Omaha. The first two plows were heavy, powerful machines designed for main line operation. In fact, 900081 is the world's largest rotary snowplow; it is over 56 feet long, 17 feet tall and weighs over 180 tons when fully ballasted and ready for operation.

The third rotary , designated 900082, was completed in October 1971. It is designed for use either on branch lines over light rail and bridges or on the main line. Much has been learned on the first two rotary plows and these lessons were put to good use in designing 900082. With an eye towards branch line operation, weight reduction was of primary importance. Still heavy (142 tons), special long wheel base trucks were designed to spread the plow's weight over a larger area and thus permit it to operate anywhere on the system.

[photo caption] 900082, the newest of UP's diesel-powered behemoths as she appeared fresh from Omaha shops in October, 1971 , is a credit to those who designed and built her.

From the outside, 900082 looks much like its predecessor, 900081 . However, inside there are many changes. From the engine through the rotary wheel drive, all components have been selected with weight reduction in mind. New devices have been incorporated which simplify the equipment arrangement, reduce weight even more and still deliver over 2000 horsepower at the rotary wheel.

Rotary snow plows have come a long way since the Leslie brothers had "a better idea." Union Pacific's mechanical department has been in large part responsible for this development. From that time in the last century when the first rotary plow proved its usefulness over the line between Granger and Huntington, until the mid-1950's, few changes were made in the original design. It remained for Union Pacific designers and craftsmen to engineer and produce a new machine. The new diesel rotaries have the characteristic " big wheels" and they ride on rails, but there the similarities end. The " internal workings" are strictly a product of modern technology.

[photo caption] From the rear of the train, 900080 can be seen chewing her way through the drifts on the Yellowstone branch.

The credit for building these machines belongs to a lot of people like F. V. (Bud) Lubischer, engineerdesign, and Fred Christensen, engineer- design, who worked out many new concepts and designs. Credit also goes to the welders who pioneered new techniques needed for special metals, to the boilermakers and blacksmiths who turned the blueprints into hard steel; the projects' successes were due to the imagination and craftsmanship of many.

The diesel-electric rotary snow plow is another tool which helps Union Pacific mean " Dependable Transportation" both summer AND winter.

###