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The Guardian Fall Team Blog

When we think of the relationship between a worker and an anchor in terms of ratios, we usually think 1:1; that is, one worker tied to a single, independent anchor. This is evidenced by the fact that the vast majority of our fall protection anchors are designed just for that: a single worker. But there are plenty of times when workers must perform their jobs in twos or threes, and the ability for two (or more) workers to tie-off to a single anchor point might be a benefit, both logistically and economically.

Up On the Roof

The first, and probably most common, situation in which multiple tie-offs might be an advantage is on the top of large buildings where several employees either need to work together during construction, or for subsequent inspections by maintenance personnel. Often, workers must traverse long distances during the course of the day, and it may not be possible (or practical) to continually connect and disconnect from anchor to anchor as they move across the roof. It might also not be practical to use a long SRL tied to a single anchor, for fear of tangling with lifelines of other workers as the job progresses.

Enter the horizontal lifeline. An HLL, such as one of our Cable or Big Boss HLLs, can be an especially effective solution by allowing multiple workers to be tied off to the same anchor (remember, an HLL is a type of anchor), yet giving them the freedom to work together or apart, and to move freely without the necessity of changing anchors. Depending on your HLL configuration, you can typically have either two or four workers tied off in Fall Arrest on a single HLL. Of course you’ll need to heed the manufacturer’s instructions and the Competent Person’s recommendations, but the ability to install a single anchor to support up to four workers is a win all the way around.

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 A Safer Option

Another benefit of many HLL installations is the ability to ensure workers remain in Fall Restraint only, versus being put at greater risk by moving into Fall Arrest. I mentioned above the option of installing a single anchor and using a long SRL to accomplish your work. While this might be a perfectly workable solution in many instances, as fall protection professionals we suggest that workers choose the safer option – always. In other words, unless a worker absolutely needs to work in Fall Arrest (where they are exposed to a fall over the leading edge), it is preferable they work in Fall Restraint instead, where they will never be exposed to the risk of a fall (By the way, if you need a refresher on the Fall Protection Hierarchy, click HERE). An HLL is an excellent way to ensure workers have access to the work area they need, while keeping them from ever reaching the edge. Properly configuring the HLL by maintaining suggested setback from the edge and using appropriate-length lanyards will simply not give workers the option to access the edge.

Don't Go Too Far Now...

Then again, there are some instances where needing to roam the entire roof isn’t necessary, and instead keeping workers in a smaller space (while still keeping them from the edge) is the goal. For residential applications, the double D-ring Ridge-It is a slender and unobtrusive anchor that installs under the ridge tiles of a roof and allows one worker on either side of the ridge to work in Fall Restraint – with the proper connector of course. And remember, if either one of those workers needs to work in Fall Arrest, the other must disconnect – only ONE worker in Fall Arrest on a Ridge-It.

The 4-Way Plate Anchor is another multiple tie-off anchor rated for two workers in Fall Restraint (or if Leading Edge work is necessary, one worker in Fall Arrest). It is compatible with wood, metal, or concrete substrates, and has multiple attachment points. Like an HLL system, properly locating the anchor and combining it with the right connector allows a great deal of flexibility and safety.

Three's A Crowd, But Up To Four Is Possible

Another great feature of the 4-Way is the ability to use it as an anchor for an HLL system. That’s right! Not only can the 4-Way be used as a stand-alone Fall Arrest/Restraint anchor, it can also be combined with our Cable Lifeline System for up to two workers in Fall Arrest or with our Big Boss HLL for up to four (yes four!) workers in Fall Arrest. By mounting 4-Way Anchors at the corners (with minimum 6’ setback) on a flat roof, then attaching our Big Boss HLL between the anchors, you now have a Fall Protection solution that can support up to four workers in Fall Restraint or Fall Arrest. Another great feature of this setup is the ability to remove the Big Boss HLL and use the 4-Ways as independent anchors as needed – a flexible solution.

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A Similar Job, Done Differently

The astute student of fall protection is now distracted by the previous example, wondering how on Earth it’s possible for a Big Boss HLL strung between two 4-Way anchors to support four workers in Fall Arrest, when the two anchors by themselves can only support one worker (per anchor) in Fall Arrest. I hear you, and here’s how it works: It’s important to understand that the shock absorbing properties of your personal fall arrest system (PFAS) are not the same as an HLL. While a PFAS relies on rip-stitch shock absorbers on lanyards or friction brakes on SRLs, the Big Boss HLL’s lifeline material is designed to s t r e t c h (see what I did there?) to reduce forces, which prevents those forces from transferring to the anchor. Because the lifeline material on a Big Boss HLL is so effective, it keeps end point forces (per worker) to 1,250 lbs. or less. Multiply this by the maximum of four possible workers and you have 5,000 lbs. Given that in this example the Big Boss is connected to two 4-Way anchor with a 5,000 lb. rating per anchor, we are still safely inside the 2:1 safety factor demanded of Fall Arrest anchors.

It’s not every day you will need an anchor system with multiple attachment points, but when you do, it’s nice to have options. And in the event an off-the-shelf option won’t serve your needs, you can always get in touch with our Engineered Services Division (ESG) – as the old saying goes, if you can dream it, they can build it.