Easy to identify and commonly used, Y-hangs have several advantages. They allow for precise rope positioning and load sharing between the two anchor points (generally two bolt anchors, or two separately placed elements on the work structure). They will also reduce impact loads in the event of anchor failure.
During your IRATA Assessment, all levels will be asked to demonstrate competence rigging a small Y-hang between anchors less than one metre apart.
L2 and L3 certifying techs will be asked to demonstrate competence rigging a Y-hang between wider anchor points, while at height.
As a general rule, large angles in the anchor system should be avoided whenever possible. The preferred maximum angle for a Y-hang is less than 90 degrees. At this angle, the weight is shared more evenly between the two anchors. Exceed that angle, and you start loading your anchors with more weight than you’re actually carrying. At 120 degrees, each anchor is holding 100% of the weight, so that the combined weight ends up being double what you’re actually carrying. At 150 degrees, things get scary: each anchor carries 200% of the weight, meaning you’re anchors are carrying 4x the weight.
In other words, always do what you can to stay inside that maximum angle.
But if you can’t avoid it, in addition to making sure that the load transferred into the anchors will not exceed the Safe Working Load of any one piece of equipment, you’ll also need to take precautions against the out-of-control swing that could result from anchor-failure. In the TACS, IRATA mentions the need for redundancy in this type of scenario. This means you may need to rig four anchors (two on each side) instead of just two total.
If you’re working with a wider Y-angle, the precautions you’ll need to take will all be listed as part of the risk assessment, and in some scenarios will include extra rigging rope.
Your IRATA assessor will be watching (from ground level, if you’re a L1) to make sure that you:
· Can successfully rig a Y-hang
o Less than 1 m apart if you’re a L1
o More than 1m apart if you’re a L2 or L3
They’ll also be checking to make sure you:
· Are aware of the dangers posed by an out-of-control swing, and the precautions to take as a result.
· Are aware of the issues related to angle loading.
During your training week, we’ll go into further detail on how to equally load both anchors. Some of this material will be covered through classroom based theory work, and the rest you’ll learn through hands-on practice.
Additional resources to check out:
TACS 6.4.5 for the source material for this blog.
ICOP Part 2, 2.11.2 for more information on the anchor system (anchors and anchor lines)
ICOP Part 2, 2.11.3 for more information on the use of anchor lines.
ICOP Figure 2.4 for a helpful diagram that illustrates the increased loading on anchors, anchor lines and anchor slings caused by an increase in the Y angle.
It would also be helpful to review our basic anchor system blog, as part of this series.
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This is part of an ongoing series, where we’re breaking down IRATA’s syllabus and clarifying exactly what ‘demonstrating competence’ and ‘demonstrating awareness’ means, and what will be expected of you on assessment day. To access the IRATA study guides, click below:
