On a hot summer day, we thought it would be cool to feature the Union Pacific Snow Plow. Designed and built by the Union Pacific Railroad in its Omaha Shop, the Museum of Transportation's rotary snow plow is the heaviest ever built weighing 367,400 pounds. (That's the same as 62 African Elephants!) Its cutting wheel could throw snow far to either side of the track as it was pushed forward at four to six mph. It is not self propelled and must be pushed by three or 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