Mr. Good Egg Farmer Photo of Mr. Good Egg Farmer rollover stimulation

During a tractor overturn a rollover protective structure (ROPS) and seat belt are 99% effective in preventing injury to the operator. It is estimated that when tractors without ROPS overturn, the operator is killed about one-fifth of the time or more. Some farmers survive these overturns, but many are injured -- some severely. These injuries sometimes result in permanent disabilities. A ROPS and a fastened seat belt can prevent nearly all of these injuries and deaths.

This activity demonstrates the effectiveness of a rollover protective structure (ROPS) and seat belt. It uses a l/l6 scale model tractor without a ROPS and seat belt, and the same tractor (or a second tractor) fitted with a ROPS and seat belt. The tractor operators are simulated with a raw eggs with faces drawn on them with felt tipped pens. The eggs are called "Mr. Good Egg farmers." The demonstration involves three steps.

Photo of tractor rolloverFirst, a Mr. Good Egg farmer is placed on the tractor seat of the model tractor without a ROPS and seat belt. The tractor is then run across a cardboard bridge placed on the floor or the top of a large table. A portion of the bridge side fails under the weight of the tractor and a sideways overturn results. (The bridge represents the bank along a stream or gully and the failure represents the slumping of the edge of the bank under the weight of the tractor.) The overturn almost always results in the Mr. Good Egg farmer being crushed.

Photo of a tractor rolloverSecond, the tractor is then retrofitted with a ROPS (or a second similar model tractor equipped with a ROPS is substituted for the first tractor). The procedure is repeated. As the tractor runs across the cardboard bridge and the "bank" fails, a sideways overturn results. The ROPS keeps the tractor from rolling on top of and crushing the second Mr. Good Egg farmer, but the egg is thrown from the tractor during the overturn and usually breaks during its impact with the surface of the floor or desk.

Photo of a tractor rolloverA third Mr. Good Egg farmer is then attached to the seat of the tractor ROPS-equipped tractor. Two pieces of Velcro sticky-backed tape are attached to the tractor seat back and bottom. Then two pieces of the matching Velcro tape is stuck to the back and bottom of the egg. When the egg is pressed into place on the tractor seat, the Velcro acts like a seat belt. It holds the egg firmly in place on the tractor seat even when the tractor is turned upside down and shaken.

Next, the tractor is run across the cardboard bridge, the "bank" fails, and a sideways overturn results. But this Mr. Good Egg farmer is almost always undamaged because it stays in the tractor seat and within the frame of safety provided by the ROPS.

This activity requires a minimum of effort and equipment on the part of the instructor. A list of all the materials needed and instructions for their assembly are provided at the external link found on this page (above left). All of these materials are easily available and, once assembled, can be reused many times with a minimum of preparation time. The only consumables are the raw eggs which can be replenished at any supermarket. Gathering the materials, constructing the simple apparatus needed, and carrying out the demonstration is also a good class project for vocational agriculture students.

Instructor's Guide and Materials