Bill Kitzes Product Safety Management

Kitzes on Safety
 

Mower Backover

Originally published in the CCH Consumer Product Safety Guide, 2001.

No, a backover is not a new gymnastics move for the 2004 Summer Olympics in Athens. A backover is a tragedy. It’s 300 plus little kids a year backed over by a riding mower or lawn tractor, many resulting in amputation. That’s nearly one every day. It’s been common knowledge in the power mower industry for 30 years. Yet the major manufacturers are just now incorporating reasonable safety measures to protect our kids. Let’s look at the history.

In 1965 the chief engineer of a prominent power mower manufacturer estimated that as many as 8,000 injuries a year resulted from a bystander being run over by a riding power mower moving in reverse, with the blades running at nearly 200 mph. While that number seems a little high, the National Safety Council and the Outdoor Power Equipment Institute (OPEI), the industry trade association, confirmed the severity of the often catastrophic backover injuries. Soon afterward, university researchers began to propose safety measures to substantially reduce or eliminate the injuries, including panic stop buttons and the relocation of the blade inside the housing.

In 1974, as part of an effort by the Consumer Product Safety Commission (CPSC) to improve the safety of power mowers through the development of mandatory safety standards, a series of meetings were held with representatives of industry, government, consumers and academics. At those meetings, the National Bureau of Standards (NBS), now known as the National Institute of Standards and Technology, suggested for the first time that an interlock could be provided on the mower that would stop the blade from rotating when shifting from forward to reverse. If the operator wanted to mow in reverse, an override could be included that required the conscious effort of the operator, thereby heightening awareness that young children could be in the area.

The manufacturers were in agreement that backover injuries were very serious. In March of 1975, the Blade Contact Sub-Committee issued a draft standard requiring that a riding mower could not travel in reverse unless the blades were stopped or otherwise rendered harmless, allowing for an override as proposed by the National Bureau of Standards. Yet by late 1977, after the CPSC had published a proposed safety standard which included a prohibition on blade rotation during reverse travel, the OPEI and the mower industry changed its mind. In opposing the requirements, the industry claimed that backover accidents were “statistically insignificant yet dramatically severe”. They seemed to believe that some perceived inconvenience to mower operators outweighed the safety of young children. In June of 1981, the CPSC engineering staff endorsed the core concepts of the 1974 NBS proposal to protect young children from amputation injuries by recommending against blade rotation during reverse travel.

In 1983 one manufacturer introduced a “no mow in reverse” lawn tractor that shut the mower down if the transmission was shifted from forward to reverse without first disengaging the blade. This mower did not provide for an override to allow reverse mowing. Other manufacturers claimed that consumers would not accept the inconvenience attendant to disengaging the blades to avoid engine shut down and would therefore bypass the system.

In what appeared to be a contradiction of their own position, the industry updated their voluntary standard, the 1986 ANSI B71.1 Safety Specification for Power Mowers and Lawn and Garden Tractors. The standard instructed the operator to do exactly what the no mow in reverse mower required, to “disengage the power to the mower before backing up”. The no mow in reverse mower provided no less convenience, it just insured that if the operator forgot to disengage the blade or decided not to, young children would not be in jeopardy. Calling on the consumer to disengage the blade while rejecting a device to insure compliance, and then complaining that consumers won’t accept it is not a response of a reasonably prudent industry. Rather than including safety measures to protect children from backover, subsequent editions of the standard eliminated the instruction to disengage the blade while shifting into reverse.

Most backover injuries occur when the consumer is backing up to turn around, not while actually mowing in reverse. Only a minority of consumers intend to mow in reverse and the override would provide them with that option. The risk of injury to children far outweighs any inconvenience to the operator to move a lever or hit a switch to stop the blade.

There has been much litigation concerning whether or not the failure to provide these safety measures to prevent backover injuries creates a defective and unreasonably dangerous condition. The results have varied from verdicts of over ten million dollars to verdicts for the defense. Too often parents using newly purchased mowers are involved in injuries to their own children. There are still hundreds of thousands, if not millions of riding mowers and lawn and garden tractors in the hands of consumers that do not include adequate protection from backover injuries.

A number of prominent manufacturers have recently begun to include systems to prevent mower blades from rotating when traveling in reverse. They include an override to allow for the requirements of any backyard. The system has been technically feasible and economically practical for many years. I applaud the manufacturers efforts. Thousands of disfiguring injuries later, it’s about time.

Please address any comments to kitzes@productsafety.com.