On the edge
Unlike most other hazards and work situations, OSHA has recognized that leading-edge work can involve extraordinary hazards that would make the use of traditional fall protection methods impractical. Employers must follow a process of controlling fall hazards through elimination, prevention and arrest. Given the very nature of leading-edge work, engineering out the hazard is nearly impossible. You need to look at fall protection strategies that address prevention and arrest.
Guardrails: Practical solutionThe traditional guardrail has long been a prevention option for leading-edge work. Guardrails offer a viable solution in several applications including flat-roof work and during maintenance operations. Guardrails prevent workers from going over the edge, protect multiple workers at the same time and require little or no training.
Potential drawbacks of guardrails are that traditional models are not normally installed during initial construction (often for aesthetic reasons), they can be a hazard to install (requiring more leading-edge work), and designers, building managers and owners seldom want to penetrate the membrane of the roof structure.
To address these concerns, temporary guardrail systems that meet OSHA requirements have recently become a viable option. Portable, lightweight and easy to install, these systems offer a practical solution to leading-edge and roof work without having to penetrate the roof membrane. Their portability allows workers to safely position them where theyâ€™re needed. They also can guard against falling through skylights; OSHA requires all skylights be guarded by either a screen or guardrail.
SRLs: The next stepThough versatile and useful, guardrails require a structure to attach to and typically protect a worker who is standing up. Often in leading-edge work, the task at hand is the installation of that very structure, and work over an edge. For these applications, itâ€™s time to move up to the next step in the hierarchy of protection: fall arrest.
Because there is normally no overhead attachment point, fall arrest during leading-edge work brings with it unique issues. Temporary portable or semi-portable anchorage connectors such as tripods and davit arms can be used to address these issues. Another prevention option is the Self Retracting Lifeline (SRL). SRLs are anchored off to a point at or near floor level, allowing the worker to walk away from the anchor point to complete his/her work.
A standard SRL is designed to be placed above the worker to minimize freefall and placed such that the cable/webbing does not come into contact with a sharp edge. The retraction capabilities of the SRL generally keep the line out of the way of the worker while providing the ability to move the SRL from anchor point to anchor point, making it versatile.
However, the SRL has some limitations due to its design. For example, the risk of a pendulum-swing-fall and free-fall increases when working away from the unit. In this instance, a standard SRL could come in contact with a sharp edge, which may cause the cable to snap. To address this and other limitations, an ANSI-approved shock absorber should be used between the harness and the SRLâ€™s snap hook. The shock absorber reduces the forces on the pinch point and thus reduces the risk of the cable breaking.
New designsNew SRL designs are being developed specifically for leading-edge work. One example from DBI/SALA features a larger cable width, which increases the strength of the cable and provides more surface contact to better distribute the force on the cable at the pinch point. This design incorporates a second shock-absorbing device at the end of the cable.
Workers, employers and safety pros need to view fall protection equipment as one more tool in their toolbox and as a strategy to protect workers while maintaining a high level of productivity.