Transcript Trench Rescue Awareness

Trench for the First Responder
Chris Bednarek
Chicago Heights Fire Department
Orientation

Extension of the Trench Rescue material in the
Technical Rescue Awareness class.

You will learn additional information about working
safely around a trench rescue scene prior to the
arrival of qualified trench rescue personnel.
Orientation

This class does not qualify you for OSFM
certification, nor does is qualify you for entry at a
trench rescue operation.

This information is intended to give the first-in
company an idea of what to do and how to go about
it safely.
Terms to Know

Angle of Repose – the greatest angle above the
horizontal plane at which loose dirt will lie
without sliding.

Back Fill – the refilling of a trench, or the material
used to refill a trench, or to fill a void between
two surfaces.

Spoil Pile – the material excavated from the trench.
More Terms to Know
Fin Form – ¾”, 14-ply, arctic white birch.
 Strong Back – a 2 x 10 or 2 x 12 attached to fin form
to create a panel for shoring the wall of a trench.
 Struts – the horizontal bracing between the trench
walls.
 Uprights – vertical supports, usually 2 x 8’s, the
depth of the trench.
 Ground Pads – 4x8 or 2x8 sheets of plywood used to
disperse weight around the edge of the trench.

Where do we see trenches?
 Commonly
 Public
works routinely work in trenches.
 Pipeline
 Areas
seen occupied and unprotected
& cable installation.
of new construction (water, sewer)
Fin-form & strong
backs
Air-Shore strut
Paratech strut
Back fill (wood &
dirt)
Ground pads
Use of multiple
types of
shores
Fin-form &
strong backs
Ground pads
Whalers
Escape ladders
OSHA
Defines a trench as an excavation that is deeper
than it is wide and is no more than 15’ wide.
 Has regulations governing operations in trenches 5’
deep or deeper.
 Regulations apply to rescues.
 Provides guidelines for trenches up to 15’ wide and
20’ deep. Custom engineering is required by a
Registered Professional Engineer beyond those
limits.

60 to 65% OF ALL FATALITIES
ARE THE WOULD-BE RESCUER
Lack of knowledge
 Lack of training
 Compassion for the victim

Trenches are Dangerous
 Once
earth is disturbed, pressure begins to
act on the trench walls.
 Sooner
 There
fail.
or later all trenches cave in.
is no way to predict when a trench will
Note the deterioration to the left corner
Vibration Hazards
 All
heavy equipment should be turned off and
secured (take the keys and block the tires).
 All
sources of vibration should be eliminated
for 300’ in every direction. This includes
roadways and railways.
Backhoes
Backhoe operators will insist they can dig the victim
out.
 OSHA statistics are riddled with cases of
disembowelment and decapitation.
 Backhoe operators cannot tell the difference
between a rock and a body.
 Weight of the backhoe adds to instability of trench
walls.
 Vibration likely to speed up secondary collapse

Atmospheric Hazards
The victim may be the result of bad air in the trench
and have no actual trauma.
 Air should be monitored every 15 minutes for O2,
CO, H2S and combustibles.
 Rescuers can fall victim to the same bad air if it is
not checked regularly.
 O2 permissible exposure limits: 19.5%-23.5%.
 Methane Gas Flammable Limits: 5.0%-15.0%.

Public Utilities as a Hazard
Many trenches are dug for utility maintenance or
installation.
 Utility cables and pipes can add to trench instability.
 Electrical utilities can pose a threat to both the victim
and the rescuer.
 Broken sewer or water lines may fill the trench,
causing a drowning potential for the victim.

CONTACT WITH UTILITIES CAN BE DANGEROUS &
CAUSE DISRUPTION TO SERVICE
Fire protection
Power grid
Traffic flow
ROADWAY UNDERMINING
Critical communications
GAS SERVICE
Heavy equipment
can fall into the
trench trapping
workers
Workers can be
struck by operating
heavy equipment
Digging their own grave…
Seattle, WA
8/8/2000
Worker killed
Rescuers using camera
to locate victim’s body
Lebanon, MO
1989
Hit 10” propane pipeline
Killed operator
1996 - Operator burned after hitting 8” gasoline
pipeline
St. Paul, MN - 1993
City crew working on sewer line hit natural gas line
Killed 3, injured 11
1988
Hit propane line
3 Workers
injured
Dirt as a Hazard
 One
cubic foot of dirt weighs 90-145 lbs.
 The average collapse is 1.5 cubic yards (4000
lbs.).
 The average victim buried under 2 feet of dirt
will be covered by 3000 lbs., about 1000 lbs.
of that will be on his chest.
 The speed of collapsing dirt is often less than
1/10th of a second.
Time…Time…Time…
 The
average trench rescue takes between 4
and 10 hours.
 Long rescue time allows for further
deterioration of trench walls.
 Rotation of rescue crews necessary to keep
people fresh.
The First-In Company
 Apparatus
should be located no closer than
50’ to the trench and should be shut down.
 Locate the victim and try to find out what was
being done at the time of the accident from
someone else on the scene.
 Approach the trench from the end, never from
the side and stay as far away as possible.
The First-In Company
If the victim is conscious, he may be able to rescue
himself if a ladder and/or shovel is lowered to him.
 Call Orland Dispatch (708/403-5584) and activate a
CART box for a trench rescue.
 Keep everyone back from the trench and shut down
all machinery on the scene.
 Shut down all roads and railways for a 300’ radius
from the scene.

The First-In Company
 Identify
any utilities that my be marked by
JULIE at the scene.
 Orange
– Communications
 Red – Electric
 White – Excavation Boundaries
 Yellow – Natural Gas
 Green – Sewer
 Blue - Water
The First-In Company
 The
location of an unconscious or trapped
victim can be marked with paint or dry-chem
at the edge of the trench.
 Ground pads will need to be laid around the
edge of the trench.
 The spoil pile must be moved a minimum of 2’
away from the edge of the trench. This must
be done while working off ground pads.
Water, Water Everywhere…
Prior to the rescue team entering the trench, all
water must be evacuated. This includes water from
a main break, ground water and rain water.
 Small amounts of water can be removed with a
sump pump in a 5 gallon bucket.
 Larger amounts of water or water which is flowing
can be removed with a vac-truck.
 The truck must be set up 300’ away and have a
safety valve in line with the vacuum hose.

Incident Command
 Establish
a trench team command structure
Rescue Officer (required) – Officer in charge of the
rescue and designates other rescue sectors.
 Rescue Safety (required ) – May be in addition to the
scene safety officer and trained to the level of
the incident.
 Rescue Operations – Officer who runs the rescue.

Medical Care for the Trench Victim
Establish medical care for the victim as soon as
protection is established and victim is accessed.
 Prepare for open & closed fractures, chest injuries,
spinal injuries, crush syndrome, hypothermia,
dehydration and hypoxia.
 Give the victim a head, eye and respiratory
protection as soon as possible.

Trench Rescue Hazards
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Hazards are not obvious
Secondary collapses are common
Dirt is heavy and moves fast
Rescues are usually long-term operations
Backhoes are not safe for victim rescue
OSHA has trench limits and regulations
Buried utilities can pose a threat to rescuers
Impact or entrapment from falling debris or equipment
Unprotected trenches are dangerous
There may be inadequate equipment for shoring
Possible legal liabilities for fire officers
The End