Rotary 101. Here's a rear-quarter view of Nevada Northern's 1907-vintage Rotary Snow Plow B. It's a slightly different look at this classic piece of MOW equipment than you typically see, and it gives you a little better view of the overall configuration of the machine. As the lettering on the side indicates, this critter weighs in at 143,400 lbs...which is on a par with the weight of a locomotive. Although it incorporates a steam boiler, it is not self-propelled. The boiler only provides power for the rotary impeller blades up front. The plow requires one or more steam locomotives to push it, depending on the depth and density of the snow, as well as the grade being cleared. The rotary is crewed by a minimum of 3 people, and often by as many as 5 or 6. A Fireman manages the fire and water levels in the boiler. He stands on the footplate between the tender and the rotary and shovels coal into the firebox. His injector controls are located inside the cab, behind the rear set of windows. The Engineer sits on the right side of the boiler. He controls the speed, power and blade bite on the impeller. The deckless nature of this cab makes it very difficult for the Engineer and Fireman to see and communicate with each other, particularly when the Fireman is on his seat. The other required crew member is the Pilot, who stands up in the pilot house up front. He may be assisted by one or more extra crew members, who may be mechanics or additional observers. The Pilot watches the track, the snow depth and the rotary's progress. He controls the direction of the discharge chute as well as the steam jets inside the intake, which are used to keep snow from caking on the impeller blades. He also controls the raising and lowering of the flanger blades. He and his assistants will use hand and whistle signals to communicate with the pusher engine crews, telling them to speed up, slow down, stop or reverse. Running this type of plow is clearly a team sport, and the Rotary Pilot is definitely the "quarterback" of the crew.
The black hatches on the side of the cab are there to provide the crew with maintenance access to the steam engines that drive the impeller. The cylinders, piston rods and connecting rods are behind the three aft hatches, and the flywheel they drive is behind the most forward one. The transmission that connects the engine to the impeller is located under the pilot house.
Although the snowplow seen here is not operational, it has recently undergone a cosmetic rehab that has left it looking like it is ready for action. Most of the cab siding has been replaced, and new paint has been applied. Mechanically however, the machine would need a fair bit of work before it could once again attack the winter drifts.
