Understanding the IRATA L1 Syllabus: Deviations
In order to prevent abrasion related damage to your rope system, avoid hazards, or get yourself in the right position for the work you’re doing in suspension, you may need to use a deviation to redirect the path of the ropes from the anchor points. If you’re working in suspension on a particularly high structure, and there’s a fair distance between you and the anchor point (with no obstructions in-between), you may use one or several deviations to help fix your position – that way your ropes won't be jostled about by the wind.
One of the main benefits of using a deviation, is that it can be rigged for rescue, whereas a re-anchor cannot. However, a re-anchor may be the safer option if you find that a large angle is being created between your anchor points.
There are two different types of deviations:
- A single-anchor deviation is usually rigged as a single anchor system, and deviates the ropes (or working line alone) by a small angle. It’s generally used to help keep the rope in a static position, or to gently adjust your positioning. This is not a good choice for avoiding any hazards.
- A double-anchor deviation uses a double anchor system, and deviates the ropes by a larger angle and distance. It’s often used to avoid hazards, like sharp edges or hot surfaces.
When working with deviations, one of the biggest dangers you’ll need to guard against is an out-of-control swing (which can be a major or minor discrepancy, depending on its severity).
That’s why a double-anchor deviation is used when rigging to avoid a hazard. In case of deviation failure, the additional anchor and the connection components that are part of the system, protect against the failure of any one item that would lead the rope tech to swing into a structure or other personnel (an out-of-control swing), or that would cause the rope to make contact with that sharp edge you were avoiding.
We’ll go into further detail on the two different types of deviations and when to use them during your training week, as well as when to use single or double protection.
Here are the deviation-related maneuvers you’ll need to demonstrate competence with during your IRATA assessment:
All levels demonstrate competence:
- Pass a single and double-anchor deviation in both ascent and descent mode.
- Understand which type of deviation is appropriate for which situation and whether other types of rigging may be more appropriate.
- Your assessor will be watching to make sure that you don’t remove any equipment from the working or safety line during this maneuver. Take appropriate precautions to avoid an out-of-control swing.
L2 and L3 demonstrate competence:For the L2 and L3 IRATA syllabus, you're required to demonstrate the correct rigging for both a single and double-anchor deviation.
- As a L2 – the angle of the deviation will be specified by your assessor.
- As a L3 – you’ll choose the appropriate angle of the deviation based on the scenario outlined by your assessor.
When rigging a deviation, pay close attention to how easily it will be to pass it while in ascent and descent mode. Some things you’ll specifically be paying attention to are: the angle and distance required to achieve the re-positioning, and the ease of use. Something else to keep in mind is anchor loading. The larger the Y-angle created by your anchors, the heavier a single load will become. You can refer to figure 2.4 in the ICOP for an example of what that looks like.
We’ll also go into further detail on all of this during your training week.
Additional resources to check out:
TACS 6.4.8 (rigging) and 6.6.8 (rope manoeuvres) for the source material for this blog.
TACS 6.4.8 for rigging requirements.
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 learn more about the rest of the IRATA L1 Syllabus, click below: