Investigation of Ladder Weld Fractures...and More!

An accident occurred when a worker fell approximately 12 feet from near the top of a fixed ladder between an upper and lower roof when the walk-through extensions separated from the ladder. Initial visual inspection revealed that the fractures occurred in welded joints between tubular sections of siderails.

Examination of the fractures in this case led to an initial hypothesis regarding the cause of failure, resulting in the accident. However, additional consideration and analyses revealed that sometimes the obvious is a red herring. This case study highlights the importance of abiding by principles of the scientific method when conducting a failure analysis. All data should be considered to either accept or reject an initial hypothesis.