IMAGE
RAIL: FREIGHT
1966 
Union Pacific #900081 Rotary Snow Plow
Rotary Snow Plow
TYPE
Union Pacific
BUILDER
This is the largest and heaviest rotary snowplow built. It is 56'2" long, 17' high and weighs 376,400 pounds. (That's the same as 62 African Elephants!) Its 12' diameter cutting wheel could throw snow far to either side of the track as it was pushed forward at four to six mph. Its hydraulically operated wings can open to permit a 14' wide cutting swath of snow. The cutting wheel can revolve up to 150 rpm. It is not self propelled and must be pushed by up to four locomotives.
A steam generator heats the carburetor, prevents the fuel and water pipes from freezing and thaws out the cutting wheel if it gets stuck. The plow engineer controls both the plow and the trailing locomotives.  The circular windows in the front of this plow revolve to keep them clear from snow. Hear more here.