A near miss working at height where 3 contractors were working next to an unprotected edge, with a fall potential of over 30 feet. They were inside the barrier, and were not using fall restraint or fall arrest equipment. 2 scaffolders were installing eyebolts (drilling activity) for a new scaffolding handrail structure. The potential for a fall was clear, not only for the 3 people but also for equipment to fall onto people working below.