Title: This%20Presentation%20Developed%20By%20Drew%20R.%20Smith
1This Presentation Developed ByDrew R. Smith
- This presentation may be modified or reproduced
by individual fire departments or training
organizations provided it is not used to generate
revenue or in any commercial manner.
2Welcome!
3Confined Space Trench Rescue Awareness
4Trench Rescue AwarenessSection
5Course Overview
6Scope
- First-in companies
- Identify hazards
- Describe initial tasks
- NOT team member training
7Length
- Confined Space - 4 hrs.
- Trench Rescue - 4 hrs.
8Requirements
- Firefighter II
- Course completion
- End-of-Course Examination
- State Written Examination
9Objectives
- As presented in class
- Describe the need for trench rescue awareness
training - Identify
- The content of the Rescue Awareness Course
10Identify
- The Office of the State Fire Marshal
certification requirements. - The OSHA definition of a trench.
- Ten hidden hazards associated with trench rescue.
- Four types of trench collapses.
- Six environmental factors which adversely effect
trench stability.
11- The requirements imposed by the Illinois
Department of Labor for persons involved in
rescue operations. - How the National Fire Protection Association,
Illinois Department of Labor, Occupational Safety
and Health Administration, ANSI and NIOSH all
interface. - The requirements of OSHA 29 CFR Part 1926 Subpart
P - Excavations as it applies to rescue
operations.
12- The requirements imposed by Illinois Department
of Labor for persons involved in rescue
operations. - The three classes of soil.
- The methods of victim and rescuer protection.
- The principles of sloping a trench.
- The principles of trench shields.
- The principles of shoring.
- Four types of shoring.
13- The components of a shoring system.
- The personal protective equipment that is
required for trench rescue. - Required entry and retrieval systems.
- Air quality monitoring and control systems.
- The initial command operations at the scene of a
trench rescue. - The initial tasks of the first-in company at the
scene of a trench rescue.
14 15The NeedforTrench RescueTraining
16Trenches are a familiar sight
- Commonly seen occupied unprotected
- Public works routinely works in trenches
performing maintenance and repair - Private contractors routinely work in trenches
installing new utilities such as water mains and
electricity.
17Danger associated with them
- Once earth is disturbed, pressure begins to act
on trench walls - Sooner or later trenches will cave-in
- Impossible to predict
- Unprotected occupants are relying on luck
18- Rescues are rare
- Fortunately we dont deal with incidents often
- Dangerous due to lack of experience
- Limited funding for training equipment
- False sense of security
- Dangerous since most hazards are hidden
19OSHA
- Regulations covering trench operations when depth
is 5 feet or more - Regulations apply to rescue scenes
20Definition of a Trench
- An excavation which is deeper than it is wide and
is less than 15 feet wide
21A trench according to OSHA
22Not a trench
23Hidden Hazards
24Types of collapses
- Slough-in
- Sidewall-in
- Shear-in
- Spoil-in
25Slough-in
26Sidewall-in
27Shear-inAKA Lip-in
28Spoil-in
To prevent a spoil-in the spoil pile is to be at
least 2 feet from the lip and laid back less than
45 degrees
29Environmental factors affecting trench stability
30Vibration
- Extremely dangerous
- Typical sources
- Roadways
- Railroads
- Digging operations
- Nearby construction/industry
31Superimposed loads
- Add weight stress to trench
- Examples
- Spoil pile
- Heavy equipment
- Work materials (cable, vaults, pipe)
- People
32Surface encumbrances
- Other structures whose support relies on the soil
at or near the trench - Examples
- Roadways
- Utility poles
- Foundations
33Wet soils/submerged soils
- Added weight
- Loss of friction
- Movement of water carrying soil
- Standing water undermining trench walls
34Exposure to elements
- Time - longer trench is open the more unstable it
will be - Sun and wind
- Freezing / Thawing
35Previously disturbed soils are common due to
trenches being located in easementsExcavation
within last 25 years makes soil previously
disturbed
36Buried utilities
- Must be located
- Often requires time-consuming hand digging
- Common problem since most trenches are located in
easements - OSHA requires that all utilities or other
structures exposed in trenches be properly
supported.
37Call JULIE 1-800-892-0123
38 39Hazards
40Human nature
- Would-be rescuers jump in start digging
- Backhoe operators try to dig victim out
41Secondary collapses
- Walls are undermined from initial collapse
- Walls are often left more unstable than before
initial collapse - Often occur while quick rescue attempt is being
made
42Weight of dirt
- 1 cubic foot of soil weights 90-145 pounds
- Average collapse is 1.5 cubic yards (4,000
pounds..) - Average worker buried under 2 feet of soil
- Total weight 3,000 pounds
- 1,000 pounds on chest area
- Worker suffocates due to inability to raise chest
43Speed of collapsing dirt
- Often less than 1/10 of a second
- Normal escapes methods ineffective
- Being pulled out with a rope
- Running out
44Rescues are usually long operations
- Commonly last 4-10 hours
- Victims must be completely uncovered before
removed - Often frozen in position
- Limbs commonly bent at odd angles
- Fractures are common
45Backhoes used for rescues
- Equipment is too powerful - cant tell a rock
from a head - Bucket too large inaccurate
- Operator will likely be excited
- Will have watched cave-in
- Will typically know the victim
- Vibration may cause additional collapses
- Weight of the backhoe
46- CASE STUDIES
- Incident when back hoe was used to try and dig
out worker with legs straddling pipe - Incident when backhoe was used to try and dig out
worker on top of charged water pipe - Incident where back hoe was used to pull on chain
wrapped around worked
47Inadequate make-shift equipment
- Normally requires large timbers (trench 12 foot
by 4 foot by 10 foot) - 12 - 4x6x4 crossbraces
- 6 - 10x10x14 walers
- 48 - 4x6x13 uprights
- Timbers may be replaced by metal rams
48Contractors often ignore OSHA limits
- OSHA only provides regulations for trenches up to
20 deep deeper requires special engineering - Contractors who have ignored safety requirements
may have also ignored the 20 limit
49Uncollapsed Trenches
50Fire Officers who do not follow procedures and
allow personnel to enter unshored trench may be
- Fined for not providing protection
- Receive major fines for injuries
- Possibly face criminal charges for deaths
- A party to a civil suit (be sued)
51 52Regulations
53General
- Follow OSHA regulations
- 29 CFR 1926 Subpart P - Excavation
- Adopt equal or more stringent regulations
54Illinois
- Not an OSHA State
- Federal OSHA governs private federal
- IDOL governs state municipal employees
- Has adopted-by-reference Federal OSHA regulations
- 29 CFR Part 1926
- Illinois Register Section 350.280
- Failure to comply results in large fines
55Requirements
56Worker protection
- Options
- Sloping
- Shielding
- Shoring
57- Determined by
- Soil class
- Work space required
- Economic factors
58Escape routes
- No more than 25 travel distance
- Ladders must extend above trench be secured
59Air quality monitoring
- May be considered confined spaces if dug in areas
where air is bad - Should monitor all trenches to be safe
60Personal protective equipment
- At minimum
- Steel toed boots
- Fire boots
- Work shoes
- Head protection
- Fire helmets
- Hard hats
61Impact protection
- Maintain clearance for loose tools
- No workers operating near heavy equipment
62Stop logs or alarms for heavy equipment near
trench
63Other worker protection
- Reflective vests for traffic areas
- Protection for specific operations
- Eye protection
- Drowning protection
- Retrieval system
64Water Removal Systems
- Pumps
- Above ground level pumping
- Monitor air in trench for CO from pumps
- If contractor has a de-watering system going,
keep it running unless it is necessary to shut it
down for safety reasons
65Soil Classifications
66Classes
- Class A - cohesive soils, clay, soils with clay
- Class B - somewhat cohesive, but not as
- good as Class A
- Class C - sandy soils, gravel, wet soils
67Soil Classification Determined by a minimum of
- One visual method
- Once manual method
68Visual check
- LOOK
- At, In Around
- Trench for Soil Characteristics
69Manual methods
- Pocket penetrometer
- Scientific methods
- Plasticity determination using rolling
- Thumb penetration test
70Thumb penetration test
- No clumps or wet Class C
- Clumps or breaks apart with effort, thumb
penetrates Class B - Clumps or thumb only dents slightly Class A
71Adjustments to basic soil class
- Wet soils - Always Class C
- Layered soils
- Must use worst layers class
- Must lower one class if layers slop toward trench
- Fissured soils must lower one class
- Fissures may be on face or near trench
- Previously disturbed soils - must lower one class
- Vibration - must lower one class
72Principles Of Worker Protection
73Methods
- Sloping
- For departments with no equipment.
- Best for recovery, not rescue
- Shielding
- Shoring
74Sloping Principles
- Laying back soil to its Angle of Repose
- Requires opening a lot of land
- Only option in some soils
75Sloping a trench
76OSHA minimum angles
- Class A - 1/2 to 1 (67.5 degrees)
- Class B - 1 to 1 (45 degrees)
- Class C - 1.5 to 1 (22.5 degrees)
77Sloping a trench
Soil Class A B C
78Shielding principles
- Strong metal boxes designed to withhold the
pressure of collapsing soil - Must be engineered for size trench soil class
- Must be level with or extend above lip of
trench. - Must not be more than 2 up off the bottom
- Usually dragged down a trench - worker may be
inside as long as no lifting is required
79Two basic types of shields
- Steel, non-adjustable
- Aluminum, adjustable
- Manual
- Hydraulic
- Pneumatic
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82Shoring
83In General...
- Works by creating arch effect
- Strong enough to prevent soil from starting to
move, but not strong enough to stop moving dirt
Strut pressurizes trench wall in all directions
84Elements
- Crossbrace (Struts)
- Uprights
- Walers - spreads pressure over additional uprights
85Sheeting
- Structural - extra uprights
- Close - side by side
- Tight - tongue groove
- Plywood
- For psychological effect margin of safety
- 1 1/8 plywood
- 3/4 Arctic white birch
- (AKA Finform or ShoreForm)
86- Basic system of FinForm Sheeting, Uprights,
Struts
Actual Spacing Determined by Soil Class and OSHA
Chart
87Timber system with close sheeting
88Specific Types of Shores
- Timber
- Screw jack
- Pneumatic
- Hydraulic
89Timber shoring
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91OSHA charts
- Six Tables In Appendix D of OSHA Regulation
- Tables C-1.1, C-1.2 and C-1.3 are for A, B C
soil using Mixed Oak of actual dimensions (4 x
6 4 x 6) - Tables C-1.1, C-1.2 and C-1.3 are for A, B C
soil using Douglas Fire of nominal dimensions (4
x 6 31/2 x 51/2)
92- Charts applicable for trenches up to 20 deep
- Timber crossbraces are pressurized by large
wedges - Impractical for rescue
- Large number dimensions
- All custom cut (slow)
- Lumber yards dont always have in stock
93Screwjack shoring
94- Large screw pipe crossbraces
- Must be designed for trench
- OSHA does not have charts
- Must be cut to size
95Pneumatic shoring
- Air driven units
- Locking collar pin
- Limited working range
- Relies on OSHA timber charts for uprights walers
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98Hydraulic shoring
- Hydraulic driven rams
- Only system which can be installed remotely
- Limited working range
- Large storage requirements
- Fast
- OSHA has charts
- Seldom requires walers
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101Shoring installation
- If you must enter trench
- Install from top down
- Preferably one on each side
- Last piece in, is 1st piece out
102Rescue shoring vs... construction shoring
- Construction
- Straight walls
- Know dimensions needed
- Rescue
- Never straight walls
- Trench could be any dimension
103Completed Shoring in Trench Should Appear as
Follows
104Company Operations
- Establish a trench training program
- Make personnel aware of hazards
- Make personnel aware of tasks which can be
performed safely - Preplan
- Develop procedures for 1st-in companies
- Develop a response plan
- Resources
- Regionalization
105Initial Operations
106- Activate response plan
- Summon MABAS Special Rescue Team upon
confirmation of collapse - Initiate Incident Command System
- Prevent personnel from entering an unprotected
trench - Prevent use of heavy equipment
- Stop sources of vibration within 300
107- Set-up zones
- Cold
- Warm
- Hot
108- Hot Operations zone is within 15 feet of
victim. No person allowed except rescuers
approved by operations officer. - Warm Control zone is within 50 feet of
victim. All rescuer staging occurs in this area.
No apparatus allowed in control zone. - Cold Exclusion zone is 150 feet of victim.
Apparatus and media are staged in this area.
Public is held outside exclusion zone.
109Perimeters designated by barricade tape or rope
and police guard
Zone distances may be adjusted as appropriate or
circumstances allow
110View trench by approaching from end
- Stay at least 10 feet away from incident site.
- Inspect trench for spoil pile location.
- Is it too close or steep?
- Inspect walls for signs of impending or recent
failure
111- Use meter to check air quality
- Begin ventilation as necessary
- Determine electrical/mechanical hazards.
112- Evaluate support needs for surface encumbrances
- Inspect and survey for buried utility problems
- Gas
- Water
- Sewer
- Electric
- Communications
113Attempt to locate and mark victims position
- Throw a rope to them if arms are free (have them
tie themselves off if possible) - Mark horizontal position within trench
- Measure record trench depth at victim
- Tape measure
- Pike pole or stick
- If no victim visible, mark soil level with an
extinguisher
114Start moving superimposed loads 2 from lip -
hand shovel spoil pile
115Lay ground pads if available
- Use available lumber
- Protects lips
- Distributes loads
- 1/2-3/4 inch plywood ideal
116Partially buried victim/Rescue mode
- Affix tag line to victim. Never pull on tag line
when victim is buried. - Provide oxygen or SCBA to victim.
- Do not enter trench other than waist deep. If
entering, must wear tag line and be on ladder.
117Prepare for injuries
- Fractures
- Lung injuries
- Head injuries
- Spinal injuries
- Respiratory system injuries
- Hypothermia
- Crush syndrome
118Call OSHACan provide technical assistance
119Following these basic procedures will result in a
safe and more efficient, expeditious rescue.
120 121In Review...
122Trenches are a familiar sight
123There are dangers associated with them
124An excavation wider than it is __________but no
wider than _________ feet is the OSHA definition
of a Trench
125Many Hazards Are Hidden
126There are 4 Types of Trench Collapses
127Environmental factors affecting trench stability
128- Vibration
- Superimposed loads
- Surface encumbrances
- Wet soils/submerged soils
- Exposure to elements
129- Previously disturbed soils - common due to
trenches being located in easements - Buried utilities
- Secondary collapses
130Weight Speed of Collapsing Dirt
131Rescues are usually long operations
132Backhoes used for rescues generally spell
D-I-S-A-S-T-E-R!
133Contractors often ignore OSHA limits
134General
- Follow OSHA regulations
- Adopt equal or more stringent regulations
- Illinois is not an OSHA State, But...
135Basic Requirements
- Escape routes
- Air quality monitoring
136Soil Classifications
137Determined By
138Adjustments to basic soil class
139Principles Of Worker Protection
- Sloping
- Shielding
- Shoring
140Shoring
- Works by creating arch effect
- Strong enough to prevent soil from starting to
move, but not strong enough to stop moving dirt
141- Sheeting
- Timber
- Screwjack
- Pneumatic
- Hydraulic
142Rescue shoring vs.Construction shoring
143Initial Operations
- Activate response plan ICS MABAS
- Prevent personnel from entering an unprotected
trench
144- Prevent use of heavy equipment
- Stop sources of vibration within 300
- Set-up zones
- Attempt to locate and mark victims position
145- Start moving superimposed loads 2 from lip
- Evaluate support needs for surface encumbrances
- Lay ground pads if available
- Monitor air quality
146- Prepare for injuries
- Call OSHA
147- Trench collapse rescue is serious business!
Mistakes could get you dead Dont screw around!