A month ago our Hand-Me-Down Rigging post discussed the need for actual training versus having riggers being taught by their co-workers. As part of that article, we invited readers to take a 5-question rigging quiz. This simple quiz was adapted from Crane Tech’s Qualified Rigger Level 1 curriculum with questions that we consider every rigger should be able to answer fairly easily.
By March 7th, there were 352 responses and we extracted the data for analysis. Imagine our surprise when we found only 59 individuals (17%) did not miss any of the questions and only 109 individuals (31%) missed one question.
Meaning the remaining 52% of respondents missed two or more questions of a five-question quiz. In our courses, students have to score a 70% or better in order to “pass”. If this was a scored quiz, anyone missing two or more questions would not have received a passing grade.
What Do These Results Mean?
While OSHA has come a long way with their requirements to have educated and “qualified” riggers on construction sites as of 2010, we believe that this basic quiz shows room for improvement in the quality of education and training provided to riggers.
Now consider if these were the scores from your organization, maybe it would be time to consider some training or re-training. If even one employee was not able to answer these basic rigging questions correctly, then you may be introducing unnecessary risk into your organization.
What Were The Responses and Correct Answers?
Here are the results of our informal quiz:
While 66% of individuals got this correct, the remaining 44% did not. The correct answer is a) Leave the pin hand tight.
When using a shackle, the screw pin threads should be fully engaged and tight, so that the shoulder of the pin is flush and makes full contact with the shackle body. Do not back off a quarter/half/full turn on the pin before use.
The reason for this? Shackles have a natural tendency to spread under load. If the shackle pin is not tight, it will allow the shackle body to stretch. Those backing off the shackle pin most likely do so because after use the pin is often too tight to loosen by hand. That is just evidence of the shackle attempting to stretch. Imagine if the pin was not tight to start with, you have likely started to introduce stretch into the shackle and over time its integrity will be compromised. If you are concerned about how to easily re-open the shackle after use, have a tool, such as a spud wrench, available to insert in the pin hole and turn to break the tension.
We were glad to note that the majority of responses knew that using at least one type of synthetic sling material would be a cause for concern in an acid environment; however, it is important to know which one. The correct response is b) Nylon.
According to OSHA 1926.251(e)(6) -“Environmental conditions.” When synthetic web slings are used, the following precautions shall be taken:
- 251(e)(6)(i) – Nylon web slings shall not be used where fumes, vapors, sprays, mists or liquids of acids or phenolics are present.
- 251(e)(6)(ii) – Polyester and polypropylene web slings shall not be used where fumes, vapors, sprays, mists or liquids of caustics are present.
- 251(e)(6)(iii) – Web slings with aluminum fittings shall not be used where fumes, vapors, sprays, mists or liquids of caustics are present.
Riggers should know these limitations. It could be a big concern if using a nylon sling in an environment where there were acidic conditions. It could easily result in a sling failure.
Hands down, when you want load security answer d) Double-wrap choker hitch is the correct response, over the other options given and 79% of respondents agreed. A double-wrap choker hitch provides full contact with the load and if more than one object is being lifted at a time, it will draw the objects together without damaging the sling.
As with any of these hitches, they should not be used when loads are long or unbalanced. Also hitches must conform to the proper D/d ratio as to not create excess stress in the sling.
This was the question that shocked us. We expected some variation of responses, but we did not expect only 36% of respondents to answer correctly with c) 1,000 pounds.
While some may say that a basic rigger doesn’t need to know this, we disagree. They may not need to be able to calculate it in detail, but they do need to understand the effect that angles can have on slings and how they can very easily impact a lift.
The illustration above, adapted from the Crane Tech Qualified Rigger Level 1 Manual, demonstrates how sling stress is distributed across slings in various configurations for a 1,000 lb load.
We were happy to see that the majority of respondents understood this concept and selected the correct answer c) the load may topple.
By its very nature, the lifting and rigging industry is working against gravity. Every load has both a vertical and horizontal center of gravity. When rigging an object, the center of gravity must be taken into consideration in order to create a safe lift. Rigging above a load’s center of gravity to keep it upright during flight.
Want to Quiz Others?
Are you interested to see how your co-workers would do? The Quiz is still online, and can be found here. Over time, as more individuals take this quiz we hope to see the results improve. If you would like a printable version for your next tailgate safety meeting, email us.
If the results from your team’s quiz surprise you, then it might be time for some training or refresher training to maintain the safety of your site. Remember, Safety through Education is more than our motto, it is our guiding principle. Call 800-290-0007 or contact us for a quote. If you want to find more about our Qualified Rigger Level 1, Qualified Rigger Level 2, or the Train-The-Trainer options, click on the links provided.