Exam (elaborations)
JATC STEP 1A questions with complete solutions
JATC STEP 1A questions with complete solutions
[Show more]
Content preview
JATC STEP 1A questions with completesolutions
Backdraft - correct answer ✔✔The explosive burning of heated gases that occurs when oxygen is
introduced into a compartment has a high concentration of flammable gases and a depleted supply of
oxygen due to an existing fire. An increase in low-level ventilation prior to upper level ventilation can
result in a backdraft. Signs of backdraft indicators include blackened windows, turbulent smoke, rapid
airflow, "puffing" of smoke, etc. The best tactic to prevent backdraft is to vertically ventilate above the
fire.
Flashover - correct answer ✔✔A rapid transition from the growth stage to the fully developed stage.
When flashover occurs, combustible materials in the compartment and gases produced by pyrolysis
ignite almost simultaneously; the result is full-room involvement. During flashover, volume of fire can
increase from 1/4th of room to entire room.
-Two significant factors for flashover progression:
-Sufficient fuel and heat release rate
-Ventilation/Oxygen
Smoke Explosion - correct answer ✔✔Form of fire gas ignition; the ignition of accumulated flammable
products of combustion and air that are within their flammable range
Rollover - correct answer ✔✔A condition where the unburned fire gases that have accumulated at the
top of a compartment ignite and flames propagate through the hot-gas layer or across the ceiling. May
indicator flashover conditions.
Dead Load - correct answer ✔✔Weight of the building itself and any equipment permanently attached
to it or built in. AKA Self Weight.
-A structure's dead load is often increased during alteration of a building. Added dead loads for which
the building has not been designed can be deadly. Examples: air conditioning units, additional trusses,
renovations to roof, etc.
, Live Load - correct answer ✔✔Live loads are any loads other than dead loads. Loads that are movable:
Water, snow, safes, firefighters, etc. Water and snow are significant collapse factors, especially when
added to a roof. Additionally FF efforts can cause building to collapse due to added weight of water.
Impact Load - correct answer ✔✔Impact loads are loads that are delivered in a short time. Crashes, fires,
explosions, collapse of structures, weight of equipment/FF placed on structure, falling trees, etc. Added
stress to a building that is under attack by fire is very dangerous. There is no such thing as no impact
load. Any stress can lead to added collapse potential. Lateral impact loads can produce disastrously high
stresses.
Describe the special considerations to firefighting that come with construction using steel beams and
members. - correct answer ✔✔During a fire, it is essential to determine how long steel members have
been exposed to heat. Critical temperature for steel is 1000 degrees F. This temp can easily be reached at
ceiling level from rising heat and smoke. Elongating steel can push out load-bearing walls and cause
collapse. If the walls are able to withstand the elongation, the steel will fail and sag somewhere in the
middle, causing collapse of upper floors or roof. A 50ft steel beam can elongate as much as 4 inches.
Water can cool steel structural members and stop elongation, which reduces the risk of a structural
collapse. Lightweight steel truss will fail much quicker than a large, heavy I-beam.
List the factors that should be considered when trying to determine the potential for structural collapse.
CACAL-SLAW - correct answer ✔✔1. Construction type
-Lightweight construction
2. Length of time fire burns
-The longer a fire burns, the greater the temperature of the fire gases in the upper levels of the structure
or compartment
3. Stage of the fire
-Collapse not likely in incipient stage. Collapse potential increases as stage of fire increases
4. Contents
3 ways:
-Contents may generate higher temperatures and rapid combustion due to higher fuel load
The benefits of buying summaries with Stuvia:
Guaranteed quality through customer reviews
Stuvia customers have reviewed more than 700,000 summaries. This how you know that you are buying the best documents.
Quick and easy check-out
You can quickly pay through credit card or Stuvia-credit for the summaries. There is no membership needed.
Focus on what matters
Your fellow students write the study notes themselves, which is why the documents are always reliable and up-to-date. This ensures you quickly get to the core!
Frequently asked questions
What do I get when I buy this document?
You get a PDF, available immediately after your purchase. The purchased document is accessible anytime, anywhere and indefinitely through your profile.
Satisfaction guarantee: how does it work?
Our satisfaction guarantee ensures that you always find a study document that suits you well. You fill out a form, and our customer service team takes care of the rest.
Who am I buying these notes from?
Stuvia is a marketplace, so you are not buying this document from us, but from seller BravelRadon. Stuvia facilitates payment to the seller.
Will I be stuck with a subscription?
No, you only buy these notes for $13.99. You're not tied to anything after your purchase.
Can Stuvia be trusted?
4.6 stars on Google & Trustpilot (+1000 reviews)
52928 documents were sold in the last 30 days
Founded in 2010, the go-to place to buy study notes for 14 years now