Re: Rotary self jacking

Further explanation from author, Mr. Burwash (posted with his permission):

So, are you a believer yet? The guy who posted about NP 10 hit the nail on the head. I was allowed all over that machine, including climbing/crawling underneath to view the jack screw mechanisms. They were only on the front truck and used to raise the plow blade (fan) for transport then lower into a plowing position.

There were two jacks, one above each wheel set. Power came from the main shaft that turned the fan. There was a sprocket on the shaft, and then about a 30 or 40 roller chain ran down to another sprocket below the floor of the cab. This sprocket drove a smaller drive shaft that was hung by a couple of pillow block bearings. This shaft extended back between the bottom ribs of the carbody and truck frame. On the end of this shaft was a worm gear that fit into its counter part worm gear/shaft that connected to the jack screws themselves.

Up in the cab there was a two stage friction clutch. You pulled back on the big lever to engage the fan, straight up was neutral, pushing forward on the lever engaged the jack screws. Raising or lowering was governed the direction the main shaft was spinning which was controlled by the reverser lever operated by the wheelman, (plow engineer.)

There was considerable tesitmony concerning the damage done to the X807, but it never made any sense to all the other authors. I too was confused by what the boys were saying until I saw those jack screws on NP 10, then it all became crystal clear what had happened and how they tried to fix it.