RESCUE-05 TRENCH RESCUE

Question 1

As defined by OSHA, a trench:

Answer 1

is a narrow excavation in relation to its length made below the surface of the ground.

Question 2

In general, a trench is:

Answer 2

deeper than the width, but the width is not greater than 15 feet.

Question 3

An excavation is defined as:

Answer 3

a man-made cut, cavity trench, or depression in the earth surface, formed by earth removal. It is usually wider than it is deep.

Question 4

How far away must all types of vehicles park from collapsed tench?

Answer 4

• Emergency vehicles: 100’
• Tech rescue team vehicle: no close than 50’
• All other traffic: 300’

Question 5

What is the distance of hazard zone around perimetry of trench collapse?

Answer 5

75’

Question 6

Any trench over _____ deep must be shored before personnel are allowed to enter.

Answer 6

5’

Question 7

All trench rescues must also follow the guidelines for _____ in regards to monitoring and ventilation.

Answer 7

a confined space rescue

Question 8

Any trench _____ mandates the use of special operation team.

Answer 8

over 8 feet deep

Question 9

What is Level I trench incident?

Answer 9

Handled by first alarm with limited assistance

Question 10

What is Level II trench incident?

Answer 10

Specially trained resources and requires resources beyond the capability of the local jurisdiction

Question 11

What is Level III trench incident?

Answer 11

Regional or state rescue teams / task forces

Question 12

What is Level IV trench incident?

Answer 12

National/FEMA teams

Question 13

What is Type A soil?

Answer 13

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.

Question 14

What is Type B soil?

Answer 14

-.5 tons per square foot and less than 1.5 tsf.

Gravel, silt, and loam

Question 15

What is Type C soil?

Answer 15

• Less than .5 tsf.
• Includes granular soils, sand, and submerged soils
• All rescue situations assume this soil

Question 16

When measuring unconfined compressive strength of cohesive type soils, the general consideration is the average weight of soil is:

Answer 16

100 pounds per square foot

Question 17

What are the distances for the hot, warm, and cold zone of trench rescue?

Answer 17

Hot 0-50’
Warm 50-200’
Cold 200-300’

Question 18

Who is responsible for directing the actual shoring, disentanglement, and removal operations associated with the trench or excavation?

Answer 18

Extrication officer (trench boss)

Question 19

Provide level area for ground pads and place within:

Answer 19

6 inches of lip of trench.

Question 20

Minimum of _____ lumber placed between spoil pile and trench on level ground. _____ between trench and spoil pile is optimal.

Answer 20

2”X12” ; 2’

Question 21

Minimum of how many ladder for emergency exits and how close to personnel?

Answer 21

2; within 25’

Question 22

What is abnormal O2 %s for trench?

Answer 22

19.5% and 23.5%

Question 23

All shoring is based on what principle?

Answer 23

double funnel

Question 24

How much pressure for air shores

Answer 24

• 200 psi

- 50 then 200 psi on corners

Question 25

All personnel are considered in the safe zone while remaining within _____ of a shore.

Answer 25

4’

Question 26

Shoring must remain within _____ of the lip of the trench and _____ from the bottom of the trench.

Answer 26

2’;2’