Licensed Professional Engineers

FORENSIC CLUES # 24 - "Alternate Designs to Hazardous Products " by Dr. L.D. Ryan



A newsletter dedicated to keeping attorneys informed of the technical side of product liability cases.

Volume 24 June/July 2007

“Alternate Designs to Hazardous Products”

By Dr. L.D. Ryan

Alternative Designs

One of the assets Safety Engineering Resources has brought to the product liability litigation table has been our ability to design and build alternative designs when the designs are not available as “after market” products. This is one of the reasons we have a complete fabrication shop. We can build prototypes of safety devices that should be on many of today’s products. This enhances any plaintiff’s case on products that we know are defective and unreasonably dangerous. If the plaintiff expert cannot demonstrate an alternative design, who can criticize the subject product? Testimony with words alone can fall flat on the ears of the jury. Testimony plus a demonstrative alternative design creates the best possible information for the jury. Even if you have your favorite bullet proof expert, we are glad to help with the alternative design. For many products, the cost of an alternative design is reasonable. Feel free to call us and get a fixed cost on an alternative design. This issue of the Forensic Clues will present a few of our alternative designs, and hopefully, this will fuel your imagination.

ROPS for ATV’s, Lawnmowers, and just about anything.

ROPS, roller-over protection structure, should be on many more vehicles than is used today. If there are ROPS on some lawn mowers, they should be on all riding lawn mowers, ATV’s, and older tractors. Safety Engineering Resources’ recent case involving a man who rolled a lawn mower lost his life in a ditch when pinned under the riding mower in a few inches of water. He would have been saved with a ROPS on his mower.

ROPS mower.jpg


One of the first ATV ROPS we designed is shown in the next photograph. The design worked and increased the center of gravity only a couple of inches. Subsequent designs consist of a bar in front of the driver that deflects the brush in addition to protecting the driver in a rollover as opposed to the complete cage shown in the photograph.

guarded ATV.jpg

ROPS for ATV’s

If slow lawn mowers, which usually mow relative flat areas, have ROPS, shouldn’t ATV’s have this same protection? ATV’s travel over very rough ground and they do so at high speeds.

 ROPS for Older Tractors:

 There are many older farm tractors without ROPS. A farm tractor without a ROPS is a death waiting to happen. Shown next is a 1946 Ford 9N with one of our alternative designs.

ROPS tractor.jpg

ROPS retrofitted to older tractor

ATV One Man Seats

ATV manufacturers warn that one person should ride an ATV even though they provide a large long seat that holds two people. In our product liability cases involving two people on an ATV, we designed, built and tested a one-man seat. It is shown next:

ATV seat.jpg

One man seat with room for driver only

The seat looks like a saddle and the test riders loved the one man ATV seat. Never use a warning when the hazard can be removed through design.

Guarding Machines Right

Guards should be permanently attached with some means to open the guard for maintenance. The limit switch should be failsafe with a method to prevent someone from circumventing the interlocked guard. Shown next is a key operated limit switch. When the guard is closed, the prong mates with the switch, which allows the machine to run and prevents tampering.

Tamper guard.jpg

Tamper resistant guard

  Knowing the After Market Products

Safety Engineering Resources has many more new alternative designs. Just as important is we know what after-market safety products are available. A guard for a crane is available to prevent electrocution of crane operators when they inadvertently hit a power line. This is a great idea that will save the lives of crane operators and workers on the ground beside the crane. The cage is insulated so that if the crane inadvertently hits a high voltage wire the electricity cannot go down the boom.


Backup Bumper for Lawn Mowers

Shown next is a bumper that fits on the back of a lawn mower that Safety Engineering Resources designed, built, and tested. There is a rubber tube across the bumper, which holds the long switch. When the switch is hit, the mower stops. Mowers should be equipped with this bumper or a no-mow-in-reverse design, since small children will often run up behind a riding mower. Children are often chopped by the lawnmower blade when the operator doesn’t see the child and backs over him or her.


Lawnmower back-over protection

Safety Stop for a falling overhead door.

We developed a simple little hook attached to an overhead door. If the cable breaks or other scenario that causes free fall, the hook swings out so that it catches on the frame holding the door track. A student who was crushed by a door would be alive if this alternative design was placed on the over head door.


Device stops freefall of overhead door

Other Alternative Designs

Engineers can find technical safety solutions. It is not so much a “state of the art” issue, but it is allowing engineers to design a safety fix with the tools of engineering that are old and proven. Some other alternative designs available are:

·A stepladder stabilizing device.

·A stepladder anti-racking design.

·A safety-lock for extension ladder.

·A built in table saw push stick and anti-kickback device.

·After-market high voltage alarm.

·Extension ladder angle meter.

·Slip clutches to eliminate unnecessarily high forces in certain machines.

·Rubber auger flights.

·Guards for rotary mowers.

·Many other items.—Product Liability Manuals

Got a product liability case? Donegal Bay Publishing has just released its new editions of the Guarding Manual and the Warning Manual. Each manual covers in depth design, theory, and application information that is applicable to a wide variety of product liability cases, since often a manufacturer fails to guard or warn a product adequately. Please visit:

©2007 Safety Engineering Resources

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