Learning the SPRAT Curriculum: Anchor Systems

There are several different methods for connecting the ropes in your system to their anchors, and they all require the same consideration for anchor placement, worker positioning, rescue method[s], avoidance of hazards, and vector forces.

During your SPRAT evaluation, all levels will be asked to demonstrate competence rigging a basic anchor system and load sharing anchor system, with some differences in what is required for each level.

For this portion of the evaluation, your SPRAT evaluator will either ask you to rig one type of anchor per complete system, or to rig a two-rope system that uses both a structural anchorage system and a load sharing anchor system. 

You will have several opportunities to demonstrate this skill throughout your evaluation, and will not necessarily be assessed on this as a separate exercise. L1 techs may be asked to combine this exercise with their demonstration of Rigging and Operating a Hauling and Lowering System) and L2 techs with their demonstration of Rigging and Operating a Rope Access System Pre-Rigged to Lower.

Simple Structural Anchorage System

A basic anchor system includes two sets of ropes (your working and safety line) and their two separate anchors. If it’s possible, it’s recommended that you attach both lines to both anchors, to protect against the possibility of equipment failure and the impact load that would result -- even if it’s unlikely, this sort of pre-planning and risk avoidance is part of your job as a rope tech (specifically if you're a L2 or L3 rope tech).

During your SPRAT Evaluation, L1 and *L3 technicians (see below) will be asked to demonstrate competence establishing a simple structural anchorage system using a structural member (e.g. steel beam).

The specifics of what your Evaluator will be watching for when rigging a simple structural anchor system is similar to what they'll be watching for when rigging a load-sharing system. Refer to the bullet points below for a breakdown of what to be aware of when completing this exercise. 

Load Sharing Anchorage System

L1 and *L3 technicians (see below) will also be asked to demonstrate competence establishing a load sharing anchorage system with two anchorages or anchorage connectors that are less than 1m apart horizontally. 

As an example, this might involve rigging to two bolt anchors in concrete or rock. 

L2 and *L3 technicians (see below) will be asked to demonstrate competence establishing a 2-point load sharing anchorage system using either:

1. Two anchors or anchor connectors that are more than 2m apart, horizontally (perpendicular to the plane of the rope).
2. Two anchors or anchor connectors that are more than 2m apart, vertically   (parallel to the plane of the rope).

While completing all of the above exercises, your SPRAT evaluator will specifically be watching to make sure that you...

• Understand and are able to explain the benefits of tying a load sharing anchorage system (as related to system strength and creating a desirable fall line for good position).
• Use an effective back-up system to avoid any consequences that would result from equipment failure.
• Consider anchor location, and the bridle angle that's created between any two anchors in a single system (more info below in 'additional resources').
• Understand the different types of slings and rigging equipment, and how/when to use them (ex. with certain structures, the ropes can be rigged by using two similar anchor slings or strops placed next to each other).
• Avoid overloading your anchorage connectors. 
• Use appropriate edge protection if an anchor puts your rope system in contact with a sharp edge or other hazard.  

In the 'read world', L1 SPRAT techs are not generally responsible for rigging an anchor system, but  you should still have a firm understanding of what makes an anchor system safe to use, and be able to voice your concerns if steps are missed, or precautions aren't taken.  

We’ll get into all details of rigging a basic and load sharing anchor system during your training week.

*This is one of 15 manoeuvres on the L3 syllabus (coloured grey) that are primarily there for review. On assessment day L3 techs will be tested on only 50% of these items. 

Most Common Discrepancies to Avoid:

1. Load distribution is not taking place in the direction of pull. 
2. The bridle angle is unnecessarily more than 120°
3. Inappropriate back-ups. In your system, the failure of any one anchor would result in the failure of the complete system, with the resultant consequences (fail)

Additional resources to check out:

7.15 of the SPRAT Evaluation Guidelines for the sub-requirements and evaluation instructions for L1s on rigging an anchorage system. L2 and L3 techs should also review this.

7.15 of the SPRAT Certification Requirements for a concise evaluation summary, related to rigging an anchorage system.

8.8 of the SPRAT Evaluation Guidelines for the sub-requirements and evaluation instructions for L2s on load-sharing anchorage systems. L3 techs should also review this.

8.8 of the SPRAT Certification Requirements for a concise evaluation summary, related to rigging a load-sharing anchorage system. 

Appendix 4 of the SPRAT Certification Requirements for more information on Angle Physics -- table 1 includes a very helpful diagram illustrating the loads applied to an anchorage systems where the forces are distributed equally based on the interior (bridle) angle.  

This is part of an ongoing series, where we’re breaking down the SPRAT Syllabus and clarifying exactly what will be expected of you on your evaluation day. To continue exploring this series and learn more about SPRAT's Technician Evaluation Form, please click below: