WITHOUT WARNING

Excavation work can be dangerous and the hazard that usually comes to most minds is the cave in. There are plenty of other hazards, but people usually think only about cave-ins when the topic of excavation safety comes up.

While the cave-in is the most “popular” hazard, I’m amazed at the common misconceptions that exists. Here are a few, and they are not listed in a particular order.

Myth: You can tell when a trench is going to cave in.

Reality: Yes, there are a few indicators that sometimes are precursors to cave-ins. The problem is that they are not always there when a cave-in happens and cannot be counted on as an early warning system. The only sure way to avoid the dangers of a cave-in is to have an adequate protective system in place.

Myth: Good soils will not cave in

Reality: All soil will cave in. Type A will cave in, Type B will cave in, and Type C will cave in. Do not be fooled by the appearance of so-called “stable soil”. In fact, the argument can be made that the more stable soils are more dangerous than the worse type C soils.

Putting this another way, the only reason we classify soil is not to put a safety rating on it. The only reason to classify soil is simply to make sure that a protective system is adequate.

We mentioned that Type A soil will cave in. Therefore, we either must slope it, shore it, or use a trench shield. The fact that we don’t have to slope Type A as much as we do Type C does not make Type A soil safe or safer. In fact, the soil that is defined as Type A such as a cemented soil or a cohesive soil, will have a greater impact on the human body than say a Type C sandy soil when it does cave in.

The advantage that we have when working with “good” soils is that they are easier to make safe. But like other soil types, they are still dangerous, and that’s the point.

Myth: A “top man” can warn the exposed employees of a cave-in in time for them to leave the area.

Reality: The era of having a “top man” is long over. We now have the “competent person” who oversees excavation safety. This competent person is to make sure that any existing or predictable hazards are eliminated. This includes cave-in hazards as well as any other hazard. The competent person’s list of responsibilities is too long to include here, but I encourage the reader to look at my recent posts, or simply comb through the OSHA Excavation Standard (Subpart P) and find every reference to the competent person.

Of course, if an employer wants to position a “top man” there is nothing to prevent that. But to be clear, the job that the “top man” would do should’ve already been covered by the designated competent person.

Conclusion: Many times, when a tragic cave-in story is reported, the spokesperson will say something to the effect that the soil inexplicably caved-in without warning. This leads us to believe that the victims of this event just happened to be in the wrong place at the wrong time and this tragedy just couldn’t be helped. That would be inaccurate.

A good excavation safety competent person training class will help dispel these types of myths. In the class the truth about the dangers of working in unprotected excavations will be taught. This is where the warnings are issued. Not in the unprotected trench.

For more information on this or other excavation topics, please go to www.trenchandexcavationsafety.com