Engineering Ethics Case Study #1: Pulverizer

Fred is a mechanical engineer who works for Super Mulcher Corporation. It manufactures the Model 1 Pulverize, a 10-hp chipper/shredder that grinds yard waste into small particles that can be composted and blended into the soil. The device is particularly popular with homeowners who are interested in reducing the amount of garden waste deposited in landfills.

The chipper/shredder has a powerful engine and a rapidly rotating blade that can easily injure operators if they are not careful. During the five years the Model 1 Pulverizer has been sold, there have been 300 reported accidents with operators. The most common accident occurs when the discharge chute gets plugged with shredded yard waste, prompting the operator to reach into the chute to unplug it. When operators reach too far, the rotating blades can cut off or badly injure their fingers.

Charlie Burns, president of Super Mulcher, calls a meeting of the engineers and legal staff to discuss ways to reduce legal liability associated with the sale of the Model 1 Pulverizer. The legal staff suggests several ways to reduce legal liability:

• Put bright yellow warning signs on the Model 1 Pulverize that say, "Danger! Rapidly rotating blades. Keep hands out when machine is running."
• Include the following warning in the owner's manual: "Operators must keep hands away from the rotating blades when machine is in operation."
• State in the owner's manual that safe operation of the Model 1 Pulverizer requires a debris collection bag placed over the discharge chute. State that operators are not to remove the debris collection bag while the Model 1 Pulverizer is running. If the discharge chute plugs, the owner is instructed to turn off the Model 1 Pulverizer, remove the debris collection bag, replace the debris collection bag, and restart the engine.

From operating the Model 1 Pulverizer, Fred knows the discharge chute has a tendency to plug. Because the machine is difficult to restart, there is a great temptation to run the unit without the debris collection bag--and to unplug the discharge chute while the unit is still running.

For each of the following scenarios, discuss the various ways Fred attempts to resolve the problem. Utilize either the Line-Drawing or other analytical techniques in your analysis. Include at least two other alternatives in your analysis.

Scenario (1) - Fred suggests to his engineering colleges that the Model I Pulverizer should be redesigned so it does not plug. His colleagues reply that the company probably cannot afford the expense of reengineering the Model I, and they conclude that the legal staff's recommendations should be sufficient. Dissatisfied, in his spare time Fred redesigns the Model I Pulverizer and solves the plugging problem in an affordable way.

Scenario (2) - Fred says nothing to his colleagues about the impracticality of requiring the machine to be run with the debris collection bag. He accepts the legal staff's advice and adds the warning signs and owner's manual instructions. No changes are made in the design of the Model I Pulverizer.

Scenario (3) - Fred suggests to his engineering colleagues that they try to convince management that the Model I Pulverizzer should be redesigned so that it does not plug. They agree and prepare a redesign plan that will cost $50,000 to implement and take their plan to management.