The Center Pivot was invented in 1948 by farmer Frank Zybach, who lived in Strasburg, Colorado.

The Center Pivot is an automated irrigation method that covers around 40 percent of the world’s croplands. The cost of the unit and installation is relatively high and runs around 1,100 USD per hectare (Ha). Therefore it is suited for large areas. The area covered by a Center Pivot can be from 3.5 Ha. to 60 Ha. The Center Pivots last for a long time, around 15-20 years depending of the quality of the equipment and the level of maintenance.The Center Pivot is built from towers based on wheels, and spans between them.  The spans  of the machine  is made from aluminum or galvinized steel pipes in differernt sizes. These pipes can be  6”, 8”, and 10” in diameter and function as a structural frame and as  the water carrier. there is an option to add an overhang segment (which just like it sounds hangs in the air on one side) that runs between 5m to 25m in a smaller diameter pipe. At the edge of the last span there can be an option to attach a corner system that can irrigate the difference between a circle and the square surrounding it. *See Diagram A. (In the diagram you can see an example of a 400m radius Center Pivot that covers 50.27 Ha).

Center Pivot  Diagram A

 

 

 

 

 

 

 

 

 

 

 

The Center Pivot is anchored in its base to a concrete pad footing and rotates around a fixed point. In that point is also the water source and main control electric panel. This machine rotates continuously while irrigating. Each tower moves in short, intermittent steps to maintain its alignment, since each segment covers different areas of the circle.Between the steel segments are emitters (sprinklers) that can be either rotating or stationary. Each type of emitter is designed for a specific set of operating conditions. Today you can find many types of suitable emitters for different purposes.Size and the uniformity of the sprinklers are calculated before installation and are mounted from the spans in different spaces, between 1.5m to 6m.

Center Pivots can be a great solution for large, relatively flat areas because of low maintenance costs and simplicity of operation. However, they aren’t appropriate for odd-shaped fields or complex topography.

Center Pivot Sapns and Overhang