111 Questions
What does the ladder company captain direct the driver to do upon approaching the location of the alarm?
Place the truck in front of a one-story 75X100-foot brick-and-joist machine shop
What does the ladder company captain determine to be the fire building?
The one-story 75X100-foot brick-and-joist machine shop
What is the ladder company captain's role in relation to the truck's forcible entry team?
Directs them to force open the normal entrance door
What is the ladder company's initial impression of their role before reaching the location of the alarm?
They serve only as a plaything for children and a supervisor of burning garbage
What action did the 'outside vent firefighter' take at the rear of the fire building?
Checked conditions and attempted to vent the rear window from the roof
What did the captain do upon realizing the severity of the situation?
Recalled previous truss roof collapses
What did the chief do upon being notified of the collapsed skylight frame?
Ordered evacuation as huge timber trusses and flames became visible
What did firefighters do when collapse became imminent?
Were ordered to evacuate to the adjoining building
What does 'tragic timber truss trilogy' refer to?
Deadly collapses in Ridgefield, Brooklyn, and Hackensack that killed 16 firefighters
What did firefighters do upon entering the factory's interior?
Entered the factory's interior and assumed the fire was small
What is the purpose of a high, decorative front parapet wall in buildings with bowstring truss roofs?
To conceal the roof shape from operating members except those on the roof
What action should firefighters take upon discovering any type of truss in a building during a fire?
Immediately relay this information to the officer in command
What role does the concave, arched underside of a bowstring truss roof play during a fire?
Acts as a 'heat sink,' allowing heat and smoke to flow upward, delaying their build-up at the floor
What challenge may firefighters face in assessing the severity of a fire in buildings with bowstring truss roofs?
Conflicting reports from those operating above and below a fire
What might mislead firefighters into thinking there is little to burn in a bowstring truss-roofed building?
A low fire load
What are three size-up indicators of a truss roof in a building as mentioned in the text?
A large open space without columns, a mounded roof shape, and certain occupancies that frequently use truss construction
Where are bowstring timber truss roofs most often found?
Prewar industrial buildings, garages, lumberyards, piers, bowling alleys, and supermarkets
How do buildings with timber trusses concealed by ceilings pose greater danger to firefighters?
Access to the truss attic space is challenging and extinguishing fires in this space is rare
What are the three main dangers posed to firefighters by timber truss construction?
Collapse of the roof pushing out a masonry wall, falling through the roof into the fire, and being crushed and burned by the collapsing roof
What is the most common type of timber truss roof characterized by a curved top chord and horizontal bottom chord?
Bowstring truss
Under fire conditions, the strength of a timber truss is determined by:
Its weakest member, and the entire section may fail as soon as the smallest web member weakens
What caused the collapse of the front masonry wall in two bowstring truss roof collapses in the Bronx, New York?
Failure of the front wall to resist the lever action of falling roof joists
What makes identifying a bowstring truss roof challenging for firefighters?
Its unique structure which is not always easy or quick to identify
What caused a firefighter's death in Los Angeles in 1998?
Timber truss roof collapse
What makes rear walls more resistant to collapse compared to front walls in buildings with bowstring truss roofs?
They are more stable and have fewer openings
What should firefighters do if the access ladder to the truss attic space cannot be found in a bowstring truss-roofed building?
Make a roof cut opening at the sloping ends of the roof deck
In a bowstring truss-roofed building with enclosed web areas of each truss, which truss is likely to fail first in the event of a serious fire between trusses?
The one where the serious fire burns
In a 100 by 100 feet building with truss sections 20 feet on center, how large an area of roof will collapse if one truss fails?
4,000 square-foot section (40x100-foot area)
What is critical for a firefighter's safety when proceeding from the roof center above a failing truss?
The direction in which they proceed
What should be the initial strategy if a hoseline cannot extinguish a fire in a place of worship?
Conduct an exterior defensive attack
What is rated as among the most unstable and the first to fail during an earthquake simulation in testing laboratories?
Church towers and steeples
What may lead to a backdraft smoke explosion in a place of worship during a fire?
Unbreakable clear plastic covering the rose window
What should be done if two hoselines do not extinguish a fire in a place of worship?
Withdraw and conduct a defensive attack from the outside
What can be effectively used for venting and as access for an aerial master stream during a church fire?
Rose window
What is the primary strategy if the interior attack does not succeed in extinguishing the fire?
Prepare for a defensive master stream
What should firefighters do if they discover that the rose window is covered with unbreakable clear plastic during a fire?
Prepare for potential backdraft smoke explosion
What is rated as one of the most unstable parts of a building during an earthquake simulation?
Church steeples
What may allow an aerial master stream to break up fire and heat waves at the ceiling peak of a burning place of worship?
Primary venting of the rose window
What should be done if two hoselines fail to extinguish a fire in a place of worship?
Withdraw and conduct defensive attack from outside
When may venting not be necessary during the initial hoseline attack on a church fire?
When smoke and heat will rise up to high ceiling
What is the primary reason for venting stained-glass windows in places of worship?
To prevent smoke explosions and flashovers
When may venting of valuable stained-glass windows be necessary?
If interior attack fails and strategy changes to exterior attack
What public relations issue may arise from venting stained-glass windows in places of worship?
Sentimental value and donations for the windows
What is a crucial reason for checking the attic in places of worship for fire spread?
Fire in the attic could lead to collapse and trap firefighters
What should firefighters do near smoldering fires to check concealed spaces for fire spread?
Open up walls and ceilings
What is a risk posed by venting that may not effectively vent smoke stratifying near the high ceiling in places of worship?
Risk to wood timber trusses
What feature of places of worship should defensive and offensive firefighting strategies be based on?
Construction type
What hazard do stone veneer surfaces pose in places of worship?
Conceal concealed spaces and poke-through holes, posing collapse hazards
What should firefighters do upon discovering any type of truss in a building during a fire?
Open up walls and ceilings near smoldering fires to check concealed spaces for fire spread
What feature is identified as unstable during earthquakes in places of worship?
Church or temple towers, especially those with steeples
What role do portable ladders play in venting stained-glass windows near a fire in places of worship?
Raised to vent stained-glass windows near the fire during initial stages
What is crucial for firefighter safety in truss constructed buildings during firefighting operations?
Communication
What contributes to rapid timber truss roof collapse during fires in places of worship?
Wax coating from burning candles
What makes places of worship, especially the tower and steeple, a collapse danger?
Unique design
What is essential for places of worship with timber truss roofs to prevent injuries and deaths at fire scenes?
Pre-fire plans and defensive strategies
What increases firefighter survival chances during fires?
Knowledge of building construction
What is crucial to prevent firefighter injuries and deaths at fire scenes?
Teamwork among firefighters
What should firefighters be aware of and take necessary precautions for when responding to fires in places of worship?
Collapse risks
What have several tragic incidents involving firefighter fatalities occurred due to in places of worship?
Truss roof collapses
What is the primary structural member supporting the weight of the roof in a church or synagogue?
Sidewalls
Which area of a burning place of worship is considered the most dangerous during a fire?
Exposure A, B, and D sides
What type of hoseline is often ineffective for extinguishing fires in the attics of places of worship?
Handheld hoselines
What can the collapse of a large church ceiling cause, leading to windows blowing out and a flashover of superheated smoke and fire gases?
An explosion-like eruption
What strategy involves using large amounts of water and high-pressure streams with maximum reach when fighting fires in places of worship?
"Big water" strategy
What should be the size of the initial attack hoseline when fighting fires in places of worship?
The largest diameter hose available
What is the primary venting location in a place of assembly like a church or synagogue?
Rose window at the front of the building and stained-glass windows near the fire on both sides of the structure.
What are similar hazards that place of worship buildings share with heavy timber mill buildings during exterior fire spread?
Radiated heat and airborne flying embers
What emotional factor can lead firefighters to take unusual risks when fighting fires in places of worship?
The significance to the community and presence of sacred objects
What should be used to protect firefighters from collapse dangers such as bell towers, steeple, ceiling, sidewalls, and roof in a burning place of worship?
Aerial master streams from safe areas
What is the recommended method for quick access into a concealed roof space in a bowstring truss-roofed building if the access ladder cannot be found?
Making a roof cut opening at the sloping ends of the roof deck
In a bowstring truss-roofed building, if a serious fire burns in one bay between trusses, which truss is likely to fail first?
The truss closest to the fire source
In a 100 by 100 feet building with truss sections 20 feet on center, if one truss fails, how large of a roof section will collapse?
4,000 square-foot section
What is the critical direction for a firefighter to proceed from the roof center above the failing truss in a bowstring truss-roofed building?
Perpendicular to the failing truss
What may need to be done if interior attack fails and strategy changes to exterior attack in a place of worship with valuable stained-glass windows?
Venting of stained-glass windows
What may create public relations problems when it comes to venting windows in places of worship?
Sentimental value and donations for the windows
What is the primary reason for venting stained-glass windows in places of worship?
Preventing smoke explosions, flashovers, and heat bank down on firefighters
What should be raised to vent stained-glass windows near the fire during initial stages?
Portable ladders
What should venting create in places of worship and where should it start near the window?
Cross ventilation, start near the top of the window working down
What risk is posed by venting that may not effectively vent smoke stratifying near the high ceiling in places of worship?
Smoke may not effectively vent, posing risk to firefighters
What is the primary structural member supporting the weight of the roof in a church or synagogue?
Sidewalls
What is the most dangerous area during a fire in a place of worship?
Exposure A side
What is the primary strategy for fighting fires in places of worship?
Using large amounts of water and high-pressure streams
What is crucial for firefighter safety in truss constructed buildings during firefighting operations?
Utilizing aerial master streams from safe areas
What should be the initial attack hoseline when fighting fires in places of worship?
Largest diameter hose available
What are the primary venting locations in a place of assembly like a church or synagogue?
Rose window at the front and stained-glass windows near the fire on both sides
What is rated as one of the most unstable parts of a building during an earthquake simulation?
Front masonry wall
What might lead to a backdraft smoke explosion in a place of worship during a fire?
Failure to vent stained-glass windows effectively
What should be used to protect firefighters from exterior fire spread problems in places of worship?
Aerial master streams directed at burning areas from safe locations
What is crucial for firefighter survival chances during fires in places of worship?
Adhering to priorities of addressing life hazard, incident stabilization, and property protection
What is the primary reason for firefighter fatalities in places of worship?
Truss roof collapses
What should firefighters prioritize to increase their chances of survival during fires?
Knowledge of building construction
What is a significant factor for safety in truss constructed buildings during firefighting operations?
Communication
What is crucial to prevent injuries and deaths at fire scenes in places of worship?
Teamwork among firefighters
What can contribute to rapid timber truss roof collapse during fires in places of worship?
Burning candle wax coating
What makes places of worship, especially the tower and steeple, a collapse danger?
Unique design complexity
What have structural engineers found about places of worship during earthquakes?
Most unstable structures in a community
What should be implemented for places of worship with timber truss roofs to enhance safety?
Pre-fire plans and defensive strategies
Where are places of worship most vulnerable during an earthquake simulation?
Tower and steeple structures
What is the most common structural member supporting the weight of the roof in a house of worship?
Timber truss roof system
What is critical for firefighter safety when responding to fires in places of worship with timber truss roofs?
Communication, teamwork, and knowledge of building construction
What is the primary strategy upon arrival at a church fire?
Assess the fire's size and determine if it can be extinguished by a hoseline
What is the first part of a building to collapse during earthquake simulations in testing laboratories?
Church steeples
What should firefighters do if two hoselines do not extinguish a fire in a place of worship?
Withdraw and conduct a defensive attack from the outside
What can be effectively used for venting and as access for an aerial master stream during a church fire?
Rose window
What may lead to a backdraft smoke explosion during a church fire?
Covering the rose window with unbreakable clear plastic
What is crucial for firefighter safety when proceeding from the roof center above a failing truss?
Maintaining awareness of potential flashover conditions
What should be done after venting the rose window during a church fire?
Decide to vent the side stained-glass window of the place of worship
When might venting not be necessary during the initial hoseline attack on a church fire?
If smoke and heat will rise up to the high ceiling, not preventing firefighters from approaching the fire
What contributes to rapid timber truss roof collapse during fires in places of worship?
The concave, arched underside of bowstring truss roofs creating large voids that trap heat and smoke
What should be prepared if the interior attack does not succeed during a church fire?
A defensive master stream strategy
What is considered among one of the most unstable parts of a building during an earthquake simulation?
Church towers and steeples
Study Notes
Fire Safety in Buildings with Bowstring Truss Roofs
- A high, decorative front parapet wall can conceal the roof shape from all operating members, except those positioned on the roof.
- Early identification of a truss during a fire is crucial for safe operations and can prevent serious injuries.
- Firefighters discovering any type of truss in a building should immediately relay this information to the officer in command.
- The concave, arched underside of a bowstring truss roof acts as a "heat sink," allowing heat and smoke to flow upward, delaying the build-up of heat and smoke at the floor.
- In buildings with a bowstring truss roof, firefighters may receive conflicting reports from those operating above and below a fire, leading to challenges in assessing the severity of the fire.
- A low fire load in a bowstring truss-roofed building may mislead firefighters into thinking there is little to burn, but there could be a significant structural fire load in the roof system.
- Three size-up indicators of a truss roof in a building include a large open space without columns, a mounded roof shape, and certain occupancies that frequently use truss construction.
- Bowstring timber truss roofs are most often found in prewar industrial buildings, garages, lumberyards, piers, bowling alleys, and supermarkets.
- The absence of a ceiling in buildings with timber truss roofs greatly assists firefighters in identifying trusses and extinguishing fires quickly.
- Buildings with timber truss roofs concealed by ceilings pose greater danger to firefighters, with examples of fatalities in such buildings.
- Access to the truss attic space in buildings with timber trusses concealed by a ceiling is challenging, and extinguishing fires in this space is rare.
- For example, the Brooklyn supermarket had a truss attic space with timber trusses concealed by ornamental tin and suspended panel ceilings, making access and extinguishment difficult.
Firefighters and Timber Truss Roofs: A Deadly Combination
- In a fire at an auto dealership in Hackensack, New Jersey, six firefighters were killed and six others survived after the truss roof collapsed 32 minutes after their arrival.
- The truss roof was made of timber and the fire was in the attic roof space created by the bowstring timber truss section.
- Timber truss construction poses three main dangers to firefighters: collapse of the roof pushing out a masonry wall, falling through the roof into the fire, and being crushed and burned by the collapsing roof.
- Timber truss roofs have a history of death and destruction in the Northeast and pose similar risks as they age in the South and West.
- Timber truss roofs are made of large wood members arranged in triangles and connected by metal connectors.
- The most common type of timber truss roof is the bowstring truss, characterized by a curved top chord and horizontal bottom chord.
- Under fire conditions, the truss is only as strong as its weakest member, and the entire section may fail as soon as the smallest web member weakens.
- Two bowstring truss roof collapses in the Bronx, New York, caused the collapse of the front masonry wall due to the failure of the front wall to resist the lever action of falling roof joists.
- The rear walls did not collapse because they were more stable and had fewer openings, making them more resistant to movement of the roof joists.
- Firefighters need to continuously size up the fire and their surroundings, but a building with a bowstring truss roof can provide misleading information due to its unique structure.
- Identifying a bowstring truss roof by its curved shape is not always easy or quick, as indicated in many textbooks and post-fire analyses.
- A firefighter was killed in Los Angeles in 1998 due to a timber truss roof collapse.
Firefighting Strategies for Church Fires
- Small-scale replicas of buildings are constructed in earthquake-testing laboratories to observe how they react during ground-moving effects of an earthquake.
- During earthquake simulations in testing laboratories, church steeples collapse first, followed by chimneys, freestanding parapet walls, nonbearing walls, and finally, bearing walls and the roof and floors collapse.
- Scientists and engineers rate parts of a building based on their susceptibility to collapse during an earthquake, with church towers and steeples being among the most unstable and the first to fail.
- Firefighters are optimists but must recognize the dangers present during fires in places of worship, where an aggressive interior attack strategy might not be as effective as on residence building fires.
- Upon arrival at a church fire, the first officer should assess the fire's size and determine if it can be extinguished by a hoseline; if not, an exterior defensive attack should be the initial strategy.
- If two hoselines do not extinguish a fire in a place of worship, firefighters should withdraw and conduct a defensive attack from the outside.
- The strategy for a defensive master stream should be prepared if the interior attack does not succeed, and positioning apparatus for defensive operations should begin.
- A rose window in a church or temple can be effectively used for venting and as access for an aerial master stream to discharge a heavy caliber stream into the upper portions of the church.
- The primary venting of the rose window may allow an aerial master stream to break up fire and heat waves at the ceiling peak of a burning place of worship.
- If the rose window is covered with unbreakable clear plastic, it creates major venting problems and allows smoke and heat buildup, leading to a backdraft smoke explosion.
- After the rose window is vented, the decision must be made to vent the side stained-glass window of the place of worship, and positioning of other master streams should be done to protect exposures.
- Venting may not be necessary during the initial hoseline attack on a church fire, as smoke and heat will rise up to the high ceiling, not preventing firefighters from approaching the fire.
Firefighting in Places of Worship
- In a church or synagogue, the weight of the roof is supported by the sidewalls, making them primary structural members.
- Incident commanders need to be aware that a collapsing roof can push out the sidewalls, and a failing wall can cause the roof to collapse.
- The exposure A, B, and D sides of a burning place of worship are the most dangerous areas during a fire.
- Attics in places of worship often contain a significant amount of wood, making handheld hoselines ineffective for extinguishing fires in these spaces.
- The collapse of a large church ceiling can cause an explosion-like eruption, blowing out windows and creating a vacuum that leads to a flashover of superheated smoke and fire gases.
- The emotional factor of fighting fires in places of worship can lead firefighters to take unusual risks, as these buildings often hold sacred objects and are of great significance to the community.
- Firefighters need to adhere to the priorities of addressing the life hazard, incident stabilization, and property protection, even in places of worship.
- The initial attack hoseline should be the largest diameter hose available and must attack the seat of the fire, while a second hoseline is needed as backup.
- Primary venting in a place of assembly should be the rose window at the front of the building and the stained-glass windows near the fire on both sides of the structure.
- The exterior fire spread problems of a place of worship are similar to heavy timber mill buildings, with radiated heat and airborne flying embers being significant hazards.
- Collapse dangers in a burning place of worship include the bell towers, steeple, ceiling, sidewalls, and roof, and firefighters should be protected from these hazards using aerial master streams from safe areas.
- The strategy for fighting fires in places of worship involves using large amounts of water and high-pressure streams with maximum reach, as well as addressing the unique hazards and emotional factors associated with these buildings.
Firefighting Strategies for Church Fires
- Small-scale replicas of buildings are constructed in earthquake-testing laboratories to observe how they react during ground-moving effects of an earthquake.
- During earthquake simulations in testing laboratories, church steeples collapse first, followed by chimneys, freestanding parapet walls, nonbearing walls, and finally, bearing walls and the roof and floors collapse.
- Scientists and engineers rate parts of a building based on their susceptibility to collapse during an earthquake, with church towers and steeples being among the most unstable and the first to fail.
- Firefighters are optimists but must recognize the dangers present during fires in places of worship, where an aggressive interior attack strategy might not be as effective as on residence building fires.
- Upon arrival at a church fire, the first officer should assess the fire's size and determine if it can be extinguished by a hoseline; if not, an exterior defensive attack should be the initial strategy.
- If two hoselines do not extinguish a fire in a place of worship, firefighters should withdraw and conduct a defensive attack from the outside.
- The strategy for a defensive master stream should be prepared if the interior attack does not succeed, and positioning apparatus for defensive operations should begin.
- A rose window in a church or temple can be effectively used for venting and as access for an aerial master stream to discharge a heavy caliber stream into the upper portions of the church.
- The primary venting of the rose window may allow an aerial master stream to break up fire and heat waves at the ceiling peak of a burning place of worship.
- If the rose window is covered with unbreakable clear plastic, it creates major venting problems and allows smoke and heat buildup, leading to a backdraft smoke explosion.
- After the rose window is vented, the decision must be made to vent the side stained-glass window of the place of worship, and positioning of other master streams should be done to protect exposures.
- Venting may not be necessary during the initial hoseline attack on a church fire, as smoke and heat will rise up to the high ceiling, not preventing firefighters from approaching the fire.
Test your knowledge of firefighting strategies and safety measures with this quiz. Learn about the challenges faced by firefighters and how to prevent tragic incidents like the one described in the scenario.
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