TRENCH RESCUE

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• TRENCH RESCUE

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INTRODUCTION

• Each year, 1,100 workers are seriously injured
  and approximately 100 workers die in trenching
  and excavating related accidents.

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TRENCH CRITERIA

• A trench is deeper than it is wide, but no more
  than 15 wide at the bottom
• Trenches over 4 requires shoring
• Spoil pile should be a minimum of 2 from edge.

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INITIAL RESPONSE

• EMS Duty Officer
• Montgomery County Police - Emergency Response
• Urban Search Rescue Team
• Utilities, as appropriate

• One Medic Unit
• One Truck Company
• One Rescue Squad/Extrication Unit
• LFRD Duty Officer
• DFRS Battalion Chief

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SPOTTING THE APPARATUS

• Proximity to the trench - not closer than 250 ft.
• Accessibility for other rescue vehicles - at
  least 100 ft. from trench

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FIRST ARRIVING

• FIRST ARRIVING UNIT MUST
• Restrict entry to site
• Establish initial command
• Position unit no closer than 250 feet
• Establish off-site staging for other responding
  apparatus
• Eliminate sources of vibration, stop and shut
  down construction equipment, stop traffic.

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SIZE-UP

• Establish ICS
• Determine the Civilian in charge
• Are there any witnesses ?
• Now find out the facts
• Identify any communication barriers

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SIZE-UP

• Identify hazards
• Downed electrical wires
• Leaking natural gas lines
• Broken water or sewer lines
• Traffic movement causing vibration
• Crowd control

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OUTER CIRCLE CHECK

• Identify witnesses to incident.
• Identify job foreman.
• Begin to establish incident perimeter, 100 feet
  minimum.

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INNER CIRCLE CHECK

• Approach site from end of trench.
• Identify victim location using witnesses.
• Identify number of patients.
• Establish patient condition if possible.
• DO NOT ENTER TRENCH

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INNER CIRCLE CHECK

• How is the patient trapped?
• Totally buried, if so how deep
• Trapped by utilities
• Where ?
• Dont forget to consider the victims SURVIVAL
  PROFILE
• Direct non entrapped personnel out of the trench.
• Establish full command structure.

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COMPLETE PHYSICAL PERIMETER
0 feet
500 Feet
Staging
Rehab

• Hot Zone
• 100 feet
• Warm Zone
• 250 feet
• Cold Zone
• 500 feet

250 feet
IC
USAR Units
Personnel Staging
100 feet
Rescue
PIO
Trench
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VICTIMS SURVIVAL PROFILE

• Time is the biggest factor
• 8-10 min. to respond
• 10 min to set up
• 18 in 2500-3000 lbs
• Most trenches fail less than 12 ft. deep and 6
  ft. wide

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SOIL EFFECTS

• IMPACT CRUSHES THE VICTIM
• Breaking Limbs
• Causing Internal Injuries
• Cuts And Abrasions
• TRAUMATIC ASPHYXIATION
• Soil Restricts Expansion Of The Victims Chest
• Blocks Airways
• Causing Suffocation

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TRENCH

• 15 ft. deep or over 6 ft. wide

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TYPES OF TRENCH ACCIDENTS

• Spoil Pile Slide

Spoil Pile Slide -occurs when improper
techniques are used and the excavated material is
NOT PLACED far enough away from the edge of the
excavation
UNSAFE SPOIL PILE
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Types of Trench Accidents

• Slough - In

• Slough Trench Lip

Slough In (Cave in) -most commonly occurs
to previously excavated material (primarily sand
and gravel mixtures)
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Types of Trench Accidents

• Side Wall Shear

Side Wall Shear -this commonly occurs in clay
type soils that are exposed to drying.
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WALL FAILURE in order

• 1. Disturbed soil
• 2. Intersecting trenches
• 3. Narrow right-of-way
• 4. Vibrations
• 5. Seepage of surface water
• 6. Drying of exposed walls
• 7. Inclined layers of soil

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TYPES OF SOIL THAT WILL FAIL in order

• Clay and or mud
• Sand
• Wet dirt probably silty clay
• Sand, gravel, and clay mix
• Rock
• Gravel
• Sand and gravel

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SOIL TYPES

• Type A - Most stable clay, silty clay, and
  hardpan (resists penetration). No soil is Type A
  if it is fissured, is subject to vibration of any
  type, has previously been disturbed, or has
  seeping water.
• Type B - Medium stability silt, sandy loam,
  medium clay and unstable dry rock previously
  disturbed soils unless otherwise classified as
  Type C soils that meet the requirements of Type
  A soil but are fissured or subject to vibration.
• Type C - Least stable gravel, loamy sand, soft
  clay, submerged soil or dense, heavy unstable
  rock, and soil from which water is freely
  seeping.
• Layered geological strata (where soils are
  configured in layers) - The soil must be
  classified on the basis of the soil
  classification of the weakest soil layer. Each
  layer may be classified individually if a more
  stable layer lies below a less stable layer, i.e.
  where a Type C soil rests on top of stable rock.

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Terms used in Trench Rescue

• Angle of repose - the greatest angle above the
  horizontal plane at which loose soil will lie
  without sliding.
• Back fill - the refilling of a trench, or the
  material use to refill a trench, or to fill a
  void between two surfaces.

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Terms

• Back shoring - the shoring of a void as found
  after a slough in, or may be used in a T
  trench.
• Cleats - temporary support for struts
• Kick out - accidental release or failure of shore
  or strut.
• Spoil pile - the material excavated from the
  trench

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Terms

• Sheeting - 1 plywood
• Struts - the horizontal bracing between the
  trench walls.
• Uprights - the vertical supports, usually 2x8s
  the depth of the trench.
• Wedges - matched sets used to hold timber struts
  in place.

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REVIEW

• Restrict Entry To Site
• Establish Initial Command
• Position Unit No Closer Than 250 Feet
• Establish Off-site Staging For Other Responding
  Apparatus
• Shut Apparatus and Equipment
• Stop all Traffic within 250 ft.
• DO NOT ENTER TRENCH

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Do NOT trade a life for a body!!!
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Lets see what you remember
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