RESCUE-05 TRENCH RESCUE Flashcards
As defined by OSHA, a trench:
is a narrow excavation in relation to its length made below the surface of the ground.
In general, a trench is:
deeper than the width, but the width is not greater than 15 feet.
An excavation is defined as:
a man-made cut, cavity trench, or depression in the earth surface, formed by earth removal. It is usually wider than it is deep.
How far away must all types of vehicles park from collapsed tench?
- Emergency vehicles: 100’
- Tech rescue team vehicle: no close than 50’
- All other traffic: 300’
What is the distance of hazard zone around perimetry of trench collapse?
75’
Any trench over _____ deep must be shored before personnel are allowed to enter.
5’
All trench rescues must also follow the guidelines for _____ in regards to monitoring and ventilation.
a confined space rescue
Any trench _____ mandates the use of special operation team.
over 8 feet deep
What is Level I trench incident?
Handled by first alarm with limited assistance
What is Level II trench incident?
Specially trained resources and requires resources beyond the capability of the local jurisdiction
What is Level III trench incident?
Regional or state rescue teams / task forces
What is Level IV trench incident?
National/FEMA teams
What is Type A soil?
1.5 tons per square foot.
Any soil with clay content is Type A.
If the soil is fissured, subject to vibration, or previously
disturbed it does not fall in this category.
What is Type B soil?
-.5 tons per square foot and less than 1.5 tsf.
Gravel, silt, and loam
What is Type C soil?
- Less than .5 tsf.
- Includes granular soils, sand, and submerged soils
- All rescue situations assume this soil
When measuring unconfined compressive strength of cohesive type soils, the general consideration is the average weight of soil is:
100 pounds per square foot
What are the distances for the hot, warm, and cold zone of trench rescue?
Hot 0-50’
Warm 50-200’
Cold 200-300’
Who is responsible for directing the actual shoring, disentanglement, and removal operations associated with the trench or excavation?
Extrication officer (trench boss)
Provide level area for ground pads and place within:
6 inches of lip of trench.
Minimum of _____ lumber placed between spoil pile and trench on level ground. _____ between trench and spoil pile is optimal.
2”X12” ; 2’
Minimum of how many ladder for emergency exits and how close to personnel?
2; within 25’
What is abnormal O2 %s for trench?
19.5% and 23.5%
All shoring is based on what principle?
double funnel
How much pressure for air shores
- 200 psi
- 50 then 200 psi on corners
All personnel are considered in the safe zone while remaining within _____ of a shore.
4’
Shoring must remain within _____ of the lip of the trench and _____ from the bottom of the trench.
2’;2’
