Weird Plow Configuration

I was perusing Craigslist and saw this advertisement for a Ferguson Plow. I see something I do not understand. There is some sort of curved metal frame piece sticking upwards from the rear of the plow. Do you know what it is or is supposed to be?

This is a single-bottom plow assembled on a two-bottom frame. This exact configuration is illustrated in some early versions of the Ferguson plow operator’s manual. The piece you see sticking up is the beam for the rear bottom of the two-bottom plow turned upside down.

The early operator’s manual suggested using this configuration when a single-bottom plow was needed as in plowing under extremely hard conditions. The bolts holding the rear beam are removed and the rear beam is turned upside down and bolted back together. Then the rear plow base, the one with the tail wheel, is moved up to the front beam. This allows you to use the two-bottom plow frame to create a single-bottom plow.

I always thought this was pretty ingenious and I would make a nice article Furrows. A single-bottom plow can be very handy when plowing small plots or gardens. Its also a great way to be able to keep using your plow if you break a moldboard, or share, and need to finish a field.