Ch. 17 Collapse caused by master stream operations Flashcards
Large caliber streams (master streams are ground based or aerial devices with a fog or straight stream capable of delivering more than how many gallons GPM to a fire?
300
Fog streams with a delivery rate of more than 300 gpm and solid stream nozzles of how many inches or more in diameter are considered LCS nozzles
1 1/2”
The destructive pressure of a LCS is greatest where?
In the area where the water leaves the nozzle.
The most serious collapse danger of a LCS is caused by what?
The large volume of water it discharges into the bldg.
- 1 gallon of water=8 lbs.
- LCS average delivery is 500 gpm
- 4000lbs or 2 tons per minute
At a bldg. fire when LCS are in use; some of the water will be vaporized by heat. Most of it will flow back to the street by doors, cracks and down stairs. an undetermined amount will be absorbed into the bldg., which can cause a collapse. In an effort to limit the amount of water, a LCS should only be directed at ______, never at ________.
Fill in the blanks
Flame, never at Smoke.
The use of LCS frequently occurs in a smoke filled atmosphere that at times blocks the view of the bldg. requiring FF’s to rely on their sense of hearing. A “splattering” sound is made by a stream that is hitting?
A brick wall
The use of LCS frequently occurs in a smoke filled atmosphere that at times blocks the view of the bldg. requiring FF’s to rely on their sense of hearing. A “Drumming” sound is made when the stream is hitting?
A wood wall
The use of LCS frequently occurs in a smoke filled atmosphere that at times blocks the view of the bldg. requiring FF’s to rely on their sense of hearing. A distant rumble indicates that the stream is operating?
Through an opening (window, holes etc.)
When an aerial stream is to be used for a quick knockdown, the master stream nozzle is most effective when placed where?
When its placed as close to the window as possible, as this position gives the stream deep penetration and its widest horizontal range inside the floor area
When there is a danger of a collapse during LCS operations the aerial master stream apparatus must be positioned out of the collapse zone. The tip of the aerial or bucket should be kept away from a weakened wall for a distance greater than?
Greater than the height of the wall above the bucket floor.
The priorities of positioning apparatus for LCS use are? (2 answers)
1st-Life safety including FF’s
2nd-Fire containment
THAT RULE NEVER CHANGES
When using the LCS for a temporary knockdown of a large body of flame members must be withdrawn to where?
FF’s inside the bldg. must be withdrawn to a safe position. Interior FF’s must withdraw to a floor below or out of the bldg. before the LCS is used.
If a exterior LCS is going to be used for final extinguishment the IC must take what actions?
The IC must prepare for the collapse of the bldg. and withdraw all members from inside the bldg. as well as those working around the perimeter of the bldg.
The collapse zone when using a LCS for final extinguishment is a distance away from the wall equal to what?
A distance equal to 1, 1 1/2, or 2 times the height of the wall.
When LCS are in use who MUST safeguard members and constantly monitor & evaluate the effectiveness of the Master stream.
-Chiefs & COMPANY OFFICERSNEW
