Flashcards in Ch. 14 Mission of Exposure Deck (35):
Exposure protection involves the _______ part of the extinguishment process - ________ the fire.
___________ is to prevent the spread of and ____________ in the assigned area.
Mission of exposure.
Extinguish any fire.
Heat transferred from one molecule to another as molecules come in direct contact with each other
______________: Flame of burning object comes in contact with another object - most significant in _______ fires.
Direct flame impingement:
Transfer of heat in the form of electromagnetic waves that travel in straight lines from the source of the fire.
Moves through a circulating medium
This method is responsible for most of the fire spread inside a structure
Two types of exposure
Interior and exterior
Two basic forms of interior exposure
Horizontal and vertical
This form of interior exposure is cause mostly by radiation and direct flame impingement
Horizontal interior exposures
*room to room*
This interior exposure caused by convection currents
Vertical interior exposures
*floor to floor*
Items of value outside the structure or area of origin that could be threatened by fire.
Are normally, but not exclusively, other structures.
Plants and shrubs.
Extinguishment process has three components
Confine (nozzle in between).
Control (cooling gases).
Need for protecting exposures depends on (3)
Number of BTUs being produced.
Ignition TEMPERATURE of exposed material.
DISTANCE the material is from the heat source.
Interior exposures are mostly affected by _______ heat, although ______ heat will ignite materials in an area more horizontal.
This indicates interior exposure fire tend to spread _______ rather than ________.
To protect horizontal interior exposures, locate the seat of the fire and ________________.
Place a hose stream between the fire and its expected avenue of spread
*close the door to involved room. Most home doors rated for 20 min*
To protect vertical interior exposures, locate the source of heat and _________________________.
Stop or check the spread of heat by convection currents.
-straight stream off ceiling.
-MANDATORY to get above fire as soon as knocked down.
Two big errors with crews assigned to exposure
First, directing stream predominantly onto original fire, neglecting exposure.
Second, MOST COMMON error is not starting with large enough line. *Line LARGER than 1 3/4 in.*
*2 1/2 in. should be FIRST line pulled*
Exposure line may have to be moved back so that an effective stream can cool the _____ in the same manner as the exterior side walls
No doubt what INTERIOR exposures deserve your attention first, ______ currents will demand that you check extensions to the ______ exposures first.
Exterior exposure factors (5)
Availability of add'l companies.
Proximity of exposed buildings.
Exterior exposure factors.
Probably as big of an influence as any:
*directs course of INTERIOR fire spread*
*choose exposure on LEE side*
Exterior exposure factors.
Direct correlation between this and effect on exposures:
More force, more spread
Things for first-in officer to consider:
Proximity of bldgs=closest bldg first.
Life safety=greatest number of people.
Economic value=structure of most value.
Occupancy type=judgement call.
Getting line between source and exposed building is first step in exposure protection.
To TOTALLY ensure fire will not attack the exposure, you need to get inside and make sure of TWO things:
Fire has not entered structure.
Make sure water and smoke are not entering exposed building.
Water spray absorbs only about ________ of the radiant heat produced by a fire.
Glass will stop only about ______ of the radiant heat being produced by a fire.
After line put in place to protect exposure, officer should send ________ member(s) of crew into structure to check for: __________.
At least one.
Fire, smoke, and water damage.
-window can't be closed, may have to place hoseline in window to cool.
*EXTREMELY important to get into attic/cockloft and RECHECK OFTEN*
Size of line taken into exposure should be commensurate with: (3)
Amount of heat.
Proximity of exposure.
Efforts outside on the side of the SOURCE fire.
Exposure group has a unique problem in that he could _____________________.
Become command for his own structure
Exposure building and/or group.
This type of incident presents an excellent opportunity for ____________.
Observing members who are on the promotion list for chief officer or captain.
-own radio channel.
Command should choose exposure officer wisely:
Experience and trust are the keys.
3 responsibilities of exposure officer
Safety of crew.
Protecting assigned exposure (application of hose stream/gaining entry).
Keeping command informed.