Carabiner Cleave

It was just another day and another experiment for engineering students at WKU.

Carabiners. D-shaped rings with a spring catch on one side. They are quite common in our everyday lives. You see small carabiners in stores, attached to reusable water bottles. Oftentimes, building or maintenance supervisors have them attached to their belts with massive amounts of keys. Or if you are a climber or caver, you are dependent upon carabiners to hold you and your gear.

Entering the McConnell Integrated Lab, mechanical and civil engineering students conducted experiments where they tested the stress versus strain of carabiners. In groups of three, students were first challenged with an intricate knot-tying exercise. Following safety protocols, and supervised by Dr. C. Warren Campbell, students first tested locking carabiners. As each carabiner was pulled apart, pieces scattered across the high bay, while computer controls measured the strength needed to break the carabiner. Students recovered all of the pieces and analyzed the different ways each group’s carabiner broke.

Students repeated the experiment using non-locking carabiners. They further compared their measurements with the carabiner strength as published by the manufacturer.

The experiment was used to demonstrate the practical use of theories and equations learned in the classroom. It also provided the students with the opportunity for forensic analysis, which is when engineers analyze a failure in a product and devise a method to correct it.

While the students enjoyed watching the carabiners fly across the room, they demonstrated a valuable aspect in the product creation, adaptation, and improvement. Many professionals and sports enthusiasts trust the manufacturer’s published specifications of the carabiners for safety in a variety of circumstances.

So before you trust your life to this D-shaped ring, check your carabiner. And if you’re not sure, ask some engineers to test it for you.