Digging trenches is a standard part of many of our policyholder operations. They are critical to those businesses involved in utilities, construction, municipalities, communications, and many others who support these types of operations.
1,000 trenches fail on average each year in the US resulting in serious injury and costly business delays. Each year 50-100 workers are killed with most of these fatalities occurring in small companies with fewer than 10 employees and more than half of trench failures are in trenches five to nine feet in depth. Not surprisingly, most of these trenches had no protective system in place to prevent the wall collapse.
Sadly, these accidents could have been prevented using simple trench safety techniques which include:
- Sloping
- Shoring or
- Shielding
Site conditions such as those listed below will impact the protective system to be used, but there is no excuse for failing to have an effective system in place before an employee enters the trench.
- Soil type
- Access
- Trench depth
Most people are surprised at the simple fact that a square foot of soil can weigh 100 pounds depending on soil type and moisture content. Many fatalities have occurred where the victim was not completely buried but was unable to breathe due to the tremendous earthen weight on his chest.
The Occupational Safety and Health Administration has specific standards that address trench safety and should be used as part of every trench safety program. Unfortunately, having a trench safety program and requiring its use are two different issues. Very often the argument is made that “we will only be in there for a few minutes” or “we aren’t going that deep!” Both statements ring hollow after the trench collapse. The worst-case scenario is when there is a realization that the employee rescue effort has quickly turned into the body retrieval process.
Through proper planning and investment, trench entries do not have to be burdensome and the necessary work can be done efficiently and safely. Shoring systems have become less expensive, more readily available, and easier to utilize over the last ten years.
While the OSHA standards state that any trench deeper than five feet must have a protective system in place, always take into account what work is to be performed in the trench and how the employee will be performing the work. Don’t assume that this rule covers every possible work scenario.