Be Careful Where You Put Your Hands!

Chopping Machine Expert Witness

Case Synopsis: A worker was monitoring the flow of vegetables into a chopping machine. The machine’s inlet would occasionally clog, requiring the worker to clear out the jammed vegetables. The plant’s procedure to clear the clog was to shut down the chopper machine, thereby stopping the blades, and then use a plastic paddle to clear the clog in the inlet. On the day of the incident, the worker chose not to shut down the machine or use the plastic paddle to clear the jam. While reaching into the inlet, the worker extended their hand into the machine, placing their hand in the path of the rotating blades. The worker sustained amputation of all four fingers and part of their hand and thumb.

The plaintiff alleged the machine was defective because it allowed the worker to be exposed to the sharp, rotating blades. They indicated the machine should have been designed to automatically shut down in the event of a clog to prevent a worker from coming into contact with the blades when they were active.

Expert Analysis: Investigation of the incident revealed there had been alterations made to the machine after it left the control of the manufacturer. As originally designed, manufactured and sold, the machine incorporated a close inlet chute/tube that was approximately four and a half feet long. A plastic paddle with a T-handle, four and a half feet long, was also supplied. The instructions in the manual for clearing an inlet tube jam indicated the machine should be turned off and the plastic paddle should be used to clear any jammed materials. The T-handle of the paddle was designed to prevent the paddle from being able to reach the blades of the chopper. The length of the inlet tube was designed to prevent workers from being able to get their hand into the chopping area and contacting the sharp blades, whether they were moving or not. At some time during the life of the machine, the inlet tube was modified with approximately three feet of the tube being removed. This left an approximately one-and-a-half-foot long inlet tube. With this modified inlet tube, the plaintiff was able to reach down the tube to come in contact with the rotating blades of the machine. This was not possible with the original design of the machine.

Result: The defendant was able to show that the original design of the chopper machine would have prevented the plaintiff’s injuries from occurring. They were also able to show the injuries occurred due to the modification which occurred to the machine after it left their control. Due to the fact the plaintiff could not support any claims against the equipment manufacturer, the manufacturer’s motion for summary judgement was granted.

John R. Yannaccone, PE, is a Senior Mechanical Engineer with DJS Associates and can be reached via email at or via phone at 215-659-2010.



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