re inside the trench.
Shielding involves using trench boxes—also known as
trench shields—or other supports to protect workers
inside a trench from collapsing soil if a cave-in occurs.
The competent person should pick a trench box that is
right for the soil type and all other site conditions.
A trench box has two large plates, which are held
apart by four horizontal cross-members.
These plates, or "shields," must be between the
sides of the trench and the work area.
The shields are strong enough to protect workers
inside from a soil collapse.
The shields can be two feet above the bottom of the
trench as long as they can support the entire depth
of the trench and there is no caving under or
behind the shield.
The top of the shield should extend at least eighteen
inches above the level of any materials that could
cave into the trench.
Trench boxes are typically used in open areas, but
they can also be used with the sloping methods
So, let's see how a trench box could have saved the
workers that we saw at the beginning of the video.
For our example, we'll assume that the workers are
in a trench with type C soil and no sloping, but
working inside a trench box.
This time, as the workers lay the sewer pipe into
the bottom of the trench, they are protected
from any possible cave-ins.
This example shows the importance of employers
following OSHA's excavation standards to ensure
that workers are provided with a safe workplace.
These types of construction deaths are preventable.
The trench cave-in prevention measures shown here
save workers' lives.
Use these protections on the job:
it could be the difference between life and death.
If you would like more information,
contact OSHA at www.osha.gov