Have you ever heard the parable about the straw that broke the camel’s back? The story has been passed down over many generations, and still carries some merit today. The basic premise is as follows:
There were two brothers, one who used a camel to haul straw, and the other who hauled straw by hand. Each day, the brother who owned the camel would load a pile of straw onto the camel and complete his delivery of straw to the market, stacking more and more straw each day. Meanwhile, the other brother would work all day making multiple trips with small loads to make enough to eat. One day the father of the two boys said to the brother who owned the camel, "Son, do not load so much straw on your camel, you should save your camel for transporting your wife and children, and work with your brother hauling straw with your hands." The brother with the camel did not heed the words of his father, and enjoyed the large sums of money he was making with his large loads of straw. Each day, the brother would pile a little more straw on the camel’s back, until one day, the camel’s back was heaping with straw, and the brother could barely add any more. He tossed one last piece of straw on its back and the camel collapsed into a heap; paralyzed with a broken back.
The moral of the story is that everything has a limit, and in this case, the more technical term is a threshold limit value (TLV). The TLV is the total value that a machine, or instrument can withstand before breaking or failing. In the case of the camel it was 500 pounds of straw. In the case of a small vehicle hitch, the TLV is 2500 pounds. Everything that has been certified and meets ISO standards needs to be stress tested to ensure compliance, standardization, safety, and guidance. The TLV is one of these measures.
Think about the many the loads that are being transported on our highways by big trucks, semis, freighters, and the various weigh-in stations along these highways. Do you know why these stations are there? Today, even our sophisticated machinery can only withstand so much pressure before reaching a critical mass and either failing, or causing too much stress on other parts of the process that it breaks down. Consider your own work site, duties, and threshold limit value of the machines you work with. Almost everyone drives a vehicle - an example of a threshold limit value in your vehicle is the Red Line. It is not good to rev your vehicle or drive it past the red line because that is an indicator that the threshold limit value may be reached, causing the engine to fail, or another possible accident or breakdown to occur.
Consider one of the greatest accidents in history, the Chernobyl nuclear powerplant disaster. This was one of the biggest nuclear fallouts known to man, and it could have been prevented had the threshold limit value on the rods been monitored more closely. Errors such as these have been reduced largely because of sensors and other digital monitors have been integrated into our daily jobs leaving less room for human error. However, the essential principles should be considered when you are learning about a new job, entering a new environment, or considering your risk assessment of the work site.
Build this into your daily risk assessment before starting a job. Ask yourself: What are the risks? What are the threshold limit values on the site? Start getting more familiar with the threshold limit values of the equipment you use, and the equipment on your site, so you know when a blowout or mechanical failure could happen. This information could save your life, as many accidents have happened on pipelines and oil rigs where the backpressure on a well or line was greater than the capacity to keep it capped, and, as a result, the lines either burst, or caps were blown. When the threshold limit value is reached, it should be considered an emergency situation, red-alert, and emergency plans should be engaged.
Ask yourself, and your co-workers what the TLVs are on the equipment you use, and the sites you work on as a fun way to learn more about safety. It's not enough to wonder what the breaking points are, you must know them, so you do not have to wonder about your safety.