1. Excavations 1
Mitch Kneeskern
CSM 2600, Au. 2012
Subpart E- Excavations
Safety while excavating is very important on a construction jobsite. It is important for many
reasons. The most important of which I feel is because it is nearly impossible to save a victim of
a cave in. Due to this fact a greater emphasis should be put on excavation safety. In this paper I
will be talking about the design of support systems, the protection of employees in excavations,
the installation and removal of support systems, access and egress points, and hazardous
atmospheres. All of the regulations are very important in ensuring the safety of employees when
excavating.
First I will be talking about the installation and removal of supports. I became interested
in the topic when Mr. Igel and Mr. Cranmer came to talk to use about excavation. They
explained to us that if a cave-in does occur it is very hard to rescue the person that is trapped.
They made me realize just how extreme a cave-in can be. I feel that the following regulation is
an important step in making sure that a collapse does not occur. According to the OSHA code
book, support systems need to be installed and removed in a way that protects workers from
cave-ins, structural collapses, and being struck by members of the support system
[1926.652(e)(1)(i)].
Installing support systems before sending workers into an excavated area can save lives
as well as make sure the construction continues without collapses. In the same way that support
systems keeps dirt from falling on the workers it also keeps the dirt from falling into the
excavated area before it is ready to be replaced.

2. Excavations 2
The OSHA hand book states that the employer or his designee must select and construct
the support systems used on their jobsite [1926.652(c)]. There are a couple of different ways in
which they can do this. If the employer decides to use timber shoring he/she must first find the
soil classification and then follow the regulations set in appendix c the subpart P. The employer
could also choose to have the support system designed by a profession engineer. In this case all
the employer would have to do is construct the systems as designed. One final way of
constructing a support system would be using the manufacturer’s tabulated data, which means
that the system would have to be constructed within the specifications of the manufacturer.
Being able to design and construct the appropriate support system in an excavation could
mean the difference between keeping all workers safe or losing the life of one or some of the
workers. Constructing a support system incorrectly could cause it to fail. If someone were
caught in the excavation when the system failed it could mean the death of that person. They
could become trapped underneath the ground and it would be very hard to get to them before
they ran out of oxygen. This is why it is important for the employer to be sure that they select
the right type of system and install it correctly.
Along with designing the support system to be used, the employer must also do the
designing of the sloping and benching system. According to OSHA regulation [1926.652(b)] the
employer or his designee must select and construct the sloping and benching systems. There are
a couple of different options in which the employer can choose from. The first option says that
the excavation must be sloped at an angle that is not steeper than one-half horizontal to one
vertical. This means that the horizontal distance of the slope has to be half of the vertical

3. Excavations 3
distance of that slope. Another option that he can choose is to construct a system in accordance
with the soil classification and the sloping and benching regulations stated in appendix B of
subpart P. One final option that the employer could choose to use is to have the system designed
by a professional engineer. In this case all the employer would have to do is construct the
system as per the designs of the engineer.
Constructing a proper sloping and or benching system when excavating helps to ensure
the safety of workers working in an excavation. These systems can be an alternative to support
systems or they can be used together. Sloping and benching systems are used to prevent cave-ins
and protect workers entering the trenches.
When workers are working in a trench it is required that they have proper access and
egress points [1926.651(c)]. In the OSHA regulations it states that ramps used by employees to
enter and exit a trench must be constructed by a competent person. Also, structural ramps that
are to be used for access and egress of equipment must be design by a competent person
qualified in structural design. This means that not just anyone can construct these ramps they
must be built by someone who has been trained to do so.
The code book also states that in any trench four feet or more in depth an egress point
must be located no more than twenty-five feet away from the workers. This allows for a quick
escape if a trench were to begin to collapse. Making sure that the workers have a fast escape is
important when trying to keep them safe. They can quickly exit the trench if they feel that
something is not right with one of the support systems mentioned above.
Testing and controls are needed to prevent employees to exposure of atmospheric
contaminants [1926.651(g)(1)]. There are a couple of things that an employer should have tested

4. Excavations 4
before they allow workers to enter a trench. First and foremost is to test for oxygen deficiencies
inside the excavation. This occurs when there is less than 19.5 percent oxygen in the
atmosphere. This can cause oxygen deprivation which can be fatal if not caught in time. Also,
tests should be performed to find out if there are other contaminants in the air that could be
harmful to the employees. In order to prevent workers from being subjected to these
contaminants controls should be put in place to keep them at an acceptable level. If controls are
put in place tests should be run regularly to ensure that they are working correctly.
These tests and controls are vital in the fight to keep a safe and health jobsite. They
allow workers to be sure that the area they are working in is safe from contamination. Also they
allow the employer to be confident when sending his employees into these trenches, knowing
that they have provided a contaminant free work area.
In this paper I have explained the safety precautions that should be followed during
excavation. This topic has interested me because it shows just how is easy it can be for someone
to get hurt when working on or in a trench. Also, after researching these regulations it allows me
to understand what needs to be done to provide a safe work place for employees. Finally, I chose
this topic because it never occurred to me that working in a trench could be so dangerous, so it
gave me a better perspective on hazard on a jobsite.