Safety Model: computer simulation helps designers and manufacturers

Skyjack and the National Institute for Occupational Safety and Health (NIOSH) are partners in a multi–year study using computer simulation to better understand safety issues of scissor platforms. Central to the effort is mathematically modeling the behavior of a 19–foot working height scissor platform under a variety of working conditions. Researchers will use the model to predict real–world behavior.

Skyjack's direct interest in the project is answering: “How do we make better safety guidelines for this type of unit?” says Brad Boehler, the Canadian company's director of product safety and liaison to NIOSH. Results also might help answer such questions as: “Does the industry have safety standards right?” and “How can we better train operators on safety?” as posed by International Powered Access Federation's technical officer, Gil Male, after hearing Boehler describe project status and results.

Skyjack has supplied NIOSH's laboratories in Tennessee with two 19–foot working height SJ3219 scissors, chosen because that height machine is the most commonly used across the industry. The company also submitted a complete set of CAD design data of that model, which NIOSH used to build the computer models.

NIOSH has been simulating the scissor lifts’ performance and comparing the results to measured performance of the real machines in tests. These include curb collisions, travel across surface depressions, and the affects of operator motion and generated forces while elevated. The objective is to confirm that the computer model accurately parallels real machine behavior, a project goal in 2007, says Boehler.

After that is “exploration of the virtual environment” and then field tests to compare/contrast findings with those from the virtual world. Points of investigation will include: assessment of harness and lanyard use, operator platform ingress/exit design features, lift stability margins, and evaluation of fall hazards and intervention measures.