Assisted Rescue Components

All of the information in this blog is in reference to ANSI Z359.4-2007 “Safety Requirements for Assisted-Rescue and Self-Rescue Systems, Sub-Systems, and Components.” 

The requirements for fall protection and fall arrest devices are a little different than rescue devices. Overall, this can be attributed to the tasks that the equipment performs. Fall protection devices need to either prevent a worker from accessing a dangerous area or arrest a worker’s fall in the event of an unintentional fall from height. Fall protection equipment must stand up to harsh environments while being capable of supporting the forces involved with arresting a worker’s fall.

Meanwhile, rescue devices need to support the weight of a worker for various periods of time. Due to the differences between arresting a fall and retrieving a fallen worker, rescue devices need to pass tests based upon rescue situations. For the purposes of this blog, we will only be explaining the testing process for connectors, full body harnesses, and rescue self-retracting lanyards (RSRLs). 

Various styles of rescue equipment function in different ways, and depending upon how they are designed to operate, it is crucially important that those devices follow ANSI Z359 code. ANSI Z359 has approved the following devices for use with assisted rescue:
• Connectors
• Harnesses
• Self-retracting lanyards with integral rescue capability
• Lanyards
• Anchorage connectors
• Winches/hoists
• Descent control devices
• Rope tackle blocks

Connector devices are fairly simple when it comes to testing requirements. They need to adhere to all of the guidelines that have been expressed in ANSI Z359.1 (as we discussed in more detail last week). ANSI Z359.1 requires dynamic, static, and salt spray testing to ensure that serious deformation or any other damage doesn’t occur to the connector device during those scenarios. Additionally, connector devices need to be able to support the same capacity as the system where they are being used. But, there aren’t many other testing requirements that are directly expressed in this particular section of the Fall Protection Code.

Harnesses need to adhere to the guidelines set within ANSI Z359.1 for full body harnesses unless the manufacturer specifically says that they are not designed for rescue purposes. Additionally, harnesses will need to undergo static and dynamic testing where the test torso must remain inside the harness during the test and afterward for one minute. Load bearing elements must remain intact and not separate from the harness.

If an evacuation harness is being used with the system, there are some extra requirements. Specifically, an evacuation harness will never be used for any purpose other than rescuing a worker. The harness must support a 3,600 lb static load during testing and endure a dynamic test without dropping a test torso for one minute after the test. Also, all harnesses must be made with straps that are a minimum of 1-5/8 inches wide with lock stitching at sewn joints in a contrasting color of thread (for easier inspection). If there are metal components on the retrieval harness, they must undergo the 48-hour salt spray test that was explained in our last blog. 

Any self-retracting lanyard with integral rescue capabilities (RSRL) will need to adhere to all of the SRL requirements that are outlined in ANSI Z359.1. An RSRL must have a clear way of engaging into (and staying in) rescue mode with both raising and lowering capabilities. And while in these modes, the RSRL must have a 3 to 1 mechanical advantage (neglecting frictional losses). The RSRL must be able to raise, lower, and hold a load after arresting the dynamic fall of a test weight. Much like the other devices used for rescue, the static strength test requires that the RSRL supports 3,100 lbs. for one minute without failing. And the RSRL must stop, start, and hold the load while supporting 125% of its maximum capacity after a salt spray test. If operational control is lost, the RSRL must still arrest all motion within four inches (or 102 mm) of travel. 

These rigorous testing requirements are just some of the ways that safety professionals regulate the different devices for people who are working at height. Since these devices need to be used for both arresting falls and rescue purposes, it is important that they be especially robust in design and function for the benefit of anyone who is relying on them.

Until the next time, stay safe up there!