Cave-in Troubles

Understandably there has been considerable discussion on why we are seeing so many cave-in fatalities this year. Simply put, these cave in injuries and fatalities are preventable and the situation is mindboggling.

From Subpart P the definition of a cave-in includes these words “. . . its sudden movement into the excavation, either by falling or sliding, in sufficient quantity so that it could entrap, bury, or otherwise injure and immobilize a person.”

I believe the root of the problem is two-fold; a lack of understanding of soils, coupled with the refusal of companies and individuals to follow established safety guidelines.

I include a lack of understanding of soils because so very few people who have attended my competent person classes over the years, can articulate with clarity, answers to simple questions such as these:

Why do soils cave in?

When is a protective system required in excavation work?

What is the practical difference between stable and unstable soils?

Because so few can answer these simple questions at the outset of a class, even though they say they’ve attended classes before, I’m only amazed that there is not even more cave in fatalities.

Why do soils cave in?

It’s because of gravity.

Far too many people I’ve talked with think that not all soils will cave in. They are convinced that “good” soil will not cave in or there must be a problem with it if it does. This is a huge misunderstanding because gravitational forces will bring all soil walls down. Stable Rock is the only soil type that will not cave in when excavated. All other soil types require an adequate protective system. Let me repeat that. Because of gravity, all soils other than Stable Rock will cave in and employees must be protected from being “entrapped, buried, or otherwise injured and immobilized”.

When is a protective system required in excavation work?

This is another question that is rarely answered correctly in the classroom. There are two parts to the answer. The first part of the answer is that for most states and in most situations, at five feet or deeper an adequate protective system is required. Some regulations have four feet as the action depth.

The second part to the answer is that in any excavation less than five feet deep that a worker could be “entrapped, buried, or otherwise injured and immobilized”, there also needs to be an adequate protective system in place since it will cave in. The way that OSHA puts this in the Federal Register is very clear. If the excavation is less than five feet deep, the competent person must be able to explain why a protective system is not required. The only acceptable answer to not having a protective system in these shallow excavations is that the worker will not be “entrapped, buried, or otherwise injured and immobilized” when it caves in. In other words, in these shallow excavations where there is no protective system in place, when the soil caves in it will not endanger the workers because of distance. The soil won't be able to reach them. Further, in these situations we also must make sure that objects in the adjacent area also do not come into the excavation and endanger workers when the side(s) cave in. A few years ago, a worker was killed in a three-foot-deep trench when a section of sidewalk fell in as the walls collapsed.

What is the practical difference between stable and unstable soils?

An entire book could be written on this topic. Simply put, soils are classified in order of their stability as Stable Rock, Type A, Type B, and Type C. There is only one reason to classify soils. That reason is to ensure that we are using an adequate protective system. The more stable the soil, there are more protective system options and the easier it is to make it safe. The more unstable the soil, the harder it is to make safe.

The important point is that Type A will cave in, Type B will cave in, and Type C will cave in. And when the cave in happens, it can “entrap, bury, or otherwise injure and immobilize a person.” And that is what is going on these days that is so disturbing.

There is not one legitimate excuse for an individual being killed in a cave in. Not one. But with the gross lack of education and the misunderstanding of the situation, I fear that the numbers will unfortunately continue to climb.

The answer to me is quality training, and then the necessity for trainees to put what is learned to use in the field, each time, without exception. And this is a call to all employers to verify that your employees who work in excavations are trained and knowledgeable.

One excuse I hear is that some excavations are difficult, so the work proceeds without a protective system. That is both illegal and it is immoral. The solution in these situations is to reach out to a trench safety professional for guidance because the answer on how to solve these problems is literally a phone call away. But it is NEVER ok to proceed and put anyone’s life at risk.

Thank you for reading this. For more information on excavation safety, I invite you to look at my book at www.trenchandexcavationsafety.com