Analysis of an Event Chair Failure: Chair Collapse

Read Consulting determined the root cause for the failure of an event chair. The chair collapse under a restaurant patron at a Cinco de Mayo event. This chair was being properly used. This is a folding chair in which one leg slides forward during deployment. The top of the moveable leg slides in a slot created by a “slider” bracket and the bottom of the chair. Normally the leg stops and is held at the end of its travel. The slider bracket is attached to the chair bottom with 7 self tapping screws that are screwed into matching “raised bosses” on the chair bottom. In this case the 4 screws at the front of the chair (i.e. where the sliding leg comes to a stop) were missing. When the patron sat on it, the leg continued to slide and the chair collapsed and caused an injury. A proper inspection of this chair would have eliminated its use. Please see Figures Below: