A scaffold system has self standing towers and brackets that are guided and supported by the towers. The towers include three legged support bases that are collapsible to make the base convenient to store and transport. The brackets includes safety latches that engage the tower in a fail safe manner to stop a bracket that may fall uncontrollably because of other equipment failure. Some of the safety latches may be rendered inoperable as the bracket is raised and lowered under power, but one safety latch remains operable at all times.