Design and Validation of a Device to Aid in Extension Ladder Setup

Joseph C. Musto, Adam C. Resnick, Michael C. Fricke


The problem of ladder base slippage is a leading cause of workplace injuries and causes a number of annual deaths.  Research has shown that ladder users tend to set up extension ladders at an angle between 66° and 69° above horizontal, which is much shallower than the specified standard of 75.5°. This results in an increase in the friction required at the base of the ladder to support the weight of the ladder and its user, and leads to an increased likelood of a slideout accident.  To counteract the problem of ladder base slipping, a device was developed to aid the user in achieving a proper setup angle.  The device uses a mechanical switch to wired to LEDs that provide the user feedback on setup angle.  The device was tested in a laboratory environment, and was shown to positively impact the ability of the user to erect the ladder at a proper angle.

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