Collapse of BB CH8 Hard

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Questions and Answers

What type of buildings are mostly found in the industrial area?

Small two-story office buildings

Apartment complexes

Large one-story factory buildings, junkyards, and empty lots (correct)

Skyscrapers and residential homes

What does the ladder company captain direct his team to do upon approaching the location of the alarm?

Ventilate the large windows and truck entrance door immediately

Force open the normal entrance door of the 75X100-foot brick-and-joist machine shop (correct)

Raise a ground ladder to the roof of exposure 4

Assist the engine company with stretching a hoseline

Which building has a hoseline already stretched to its front by the engine company?

A nearby residential home

Exposure 4

Exposure 2

One-story 75X100-foot brick-and-joist machine shop (correct)

What is the ladder company's initial assessment of their role in the industrial area?

They feel like they serve only as a plaything for children and a supervisor of burning garbage Signup and view all the answers

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 Signup and view all the answers

What did the captain do upon realizing the severity of the situation?

Recalled previous truss roof collapses Signup and view all the answers

What led to the chief ordering evacuation?

Huge timber trusses and flames becoming visible in the machine shop Signup and view all the answers

What is referred to as the 'timber truss trilogy'?

Deadly collapses in the 1960s, 1970s, and 1980s that killed 16 firefighters Signup and view all the answers

What did the firefighter on the roof radio about?

Heavy fire in the bowstring truss roof Signup and view all the answers

What did firefighters assume upon entering the factory's interior?

The fire was small and vented rear windows from inside the building Signup and view all the answers

What action did the chief take upon arrival?

Ordered evacuation as huge timber trusses and flames became visible in machine shop Signup and view all the answers

What made firefighters realize that collapse was imminent?

Radio report about collapsed skylight frame by firefighter on roof Signup and view all the answers

What does 'timber truss trilogy' specifically refer to?

'Timber truss trilogy' refers to deadly collapses in 1960s, 1970s, and 1980s that killed 16 firefighters Signup and view all the answers

What did specific details include regarding 'timber truss trilogy'?

Deadly collapses in the 1960s, 1970s, and 1980s that killed 16 firefighters Signup and view all the answers

What are the three main dangers that timber truss construction poses 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 Signup and view all the answers

What is the most common type of timber truss roof?

Bowstring truss Signup and view all the answers

What can cause the collapse of a front masonry wall in a building with a bowstring truss roof?

Failure of the front wall to resist the lever action of falling roof joists Signup and view all the answers

Why did the rear walls not collapse in the incidents in Bronx, New York?

They were more stable and had fewer openings, making them more resistant to movement of the roof joists Signup and view all the answers

What makes sizing up a fire difficult in a building with a bowstring truss roof?

The unique structure of the bowstring truss roof can provide misleading information about fire and surroundings Signup and view all the answers

Why is identifying a bowstring truss roof by its curved shape not always easy or quick?

As indicated in many textbooks and post-fire analyses Signup and view all the answers

What caused a firefighter's death in Los Angeles in 1998?

Timber truss roof collapse Signup and view all the answers

What are timber truss roofs made of?

Large wood members arranged in triangles and connected by metal connectors. Signup and view all the answers

Under fire conditions, how strong is a timber truss?

Only as strong as its weakest member, and may fail as soon as the smallest web member weakens. Signup and view all the answers

What makes timber truss roofs pose similar risks as they age in different regions?

The structural weaknesses become more pronounced over time. Signup and view all the answers

What kind of space was created by the bowstring timber truss section where the fire occurred in Hackensack, New Jersey?

Attic roof space Signup and view all the answers

What is the purpose of a decorative front parapet wall in buildings with bowstring truss roofs?

To conceal the roof shape from all operating members, except those positioned on the roof Signup and view all the answers

What is a key challenge faced by firefighters in buildings with bowstring truss roofs?

Receiving conflicting reports from those operating above and below a fire Signup and view all the answers

What is the role of early identification of a truss during a fire in buildings with bowstring truss roofs?

Crucial for safe operations and can prevent serious injuries Signup and view all the answers

What function does the concave, arched underside of a bowstring truss roof serve during a fire?

"Heat sink," allowing heat and smoke to flow upward, delaying the build-up of heat and smoke at the floor Signup and view all the answers

What might mislead firefighters into underestimating the potential fire hazard in buildings with bowstring truss roofs?

A low fire load in the building Signup and view all the answers

What are three size-up indicators of a truss roof in a building?

Large open space without columns, mounded roof shape, certain occupancies frequently using truss construction Signup and view all the answers

Where are bowstring timber truss roofs most often found?

Prewar industrial buildings, garages, lumberyards, piers, bowling alleys, and supermarkets Signup and view all the answers

How does the absence of a ceiling impact firefighting operations in buildings with timber truss roofs?

Greatly assists firefighters in identifying trusses and extinguishing fires quickly Signup and view all the answers

What makes access to the truss attic space challenging in buildings with timber trusses concealed by a ceiling?

Ornamental tin and suspended panel ceilings obstruct access to the truss attic space Signup and view all the answers

What is the recommended method for gaining quick access into a concealed roof space in a building with a bowstring truss-roofed attic?

Making a roof cut opening at the sloping ends of the roof deck Signup and view all the answers

In a bowstring truss-roofed building with enclosed web areas and a serious fire burning in one bay between trusses, which truss is likely to fail first?

The truss closest to the fire source Signup and view all the answers

In a 100 by 100 feet building with truss sections 20 feet on center, how much roof section will collapse if one truss fails?

4,000 square-foot section of roof Signup and view all the answers

When a firefighter proceeds from the roof center above the failing truss, what direction may provide temporary safety?

20 feet in a direction perpendicular to the failing truss Signup and view all the answers

What is crucial for firefighter safety in places of worship with timber truss roofs?

Pre-fire plans and defensive strategies Signup and view all the answers

What contributes to rapid timber truss roof collapse during fires in places of worship?

Wax coating from burning candles Signup and view all the answers

What is often the most unstable structure in a community during earthquakes?

Tower and steeple of places of worship Signup and view all the answers

What is a collapse danger in a house of worship, especially the tower and steeple?

The unique design Signup and view all the answers

What do firefighters need to be aware of and take necessary precautions when responding to fires in places of worship?

Collapse risks Signup and view all the answers

What is essential for safety in truss constructed buildings during firefighting operations?

Ensuring structural integrity Signup and view all the answers

What is the purpose of venting stained-glass windows in places of worship during a fire?

To prevent smoke explosions and flashovers Signup and view all the answers

What is the risk associated with not effectively venting smoke stratifying near the high ceiling in places of worship?

Risk to wood timber trusses Signup and view all the answers

What should be considered when determining firefighting strategies for places of worship?

Construction type Signup and view all the answers

What hazard do stone veneer surfaces pose in places of worship during a fire?

Concealed spaces and collapse hazards Signup and view all the answers

What should firefighters do during the initial stages to vent stained-glass windows near the fire?

Raise portable ladders to vent stained-glass windows Signup and view all the answers

Why is checking the attic for fire spread crucial in places of worship?

Fire in the attic could lead to collapse and trap firefighters Signup and view all the answers

What should be the initial strategy if a hoseline cannot extinguish a fire in a place of worship?

Withdraw and conduct a defensive attack from the outside Signup and view all the answers

What is the primary danger associated with a covered rose window in a place of worship during a fire?

Smoke and heat buildup Signup and view all the answers

What should be done after venting the rose window during a church fire?

Vent the side stained-glass window Signup and view all the answers

What is the purpose of an aerial master stream in a burning place of worship?

To break up fire and heat waves at the ceiling peak Signup and view all the answers

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 Signup and view all the answers

What is the first part of a church building to collapse during earthquake simulations?

Church steeples Signup and view all the answers

What should be prepared if an interior attack does not succeed during a church fire?

Defensive master stream strategy Signup and view all the answers

What is rated among the most unstable parts of a building during an earthquake simulation?

Church towers and steeples Signup and view all the answers

What strategy should be adopted if it is determined that a church fire cannot be extinguished by a hoseline?

Conduct an exterior defensive attack Signup and view all the answers

What is a primary structural member in a church or synagogue?

Sidewalls Signup and view all the answers

Which area of a burning place of worship is considered the most dangerous during a fire?

Exposure A, B, and D sides Signup and view all the answers

What makes handheld hoselines ineffective for extinguishing fires in attics of places of worship?

Significant amount of wood Signup and view all the answers

What can the collapse of a large church ceiling cause?

Explosion-like eruption Signup and view all the answers

What emotional factor can lead firefighters to take unusual risks in places of worship?

Sacred objects inside the building Signup and view all the answers

What should be the priorities for firefighters when fighting fires in places of worship?

Addressing the life hazard, incident stabilization, property protection Signup and view all the answers

What is recommended as the size for the initial attack hoseline when fighting fires in places of worship?

Largest diameter hose available Signup and view all the answers

Where should primary venting be done in a place of assembly?

Rose window at the front and stained-glass windows near the fire on both sides Signup and view all the answers

What are exterior fire spread problems in a place of worship similar to?

Heavy timber mill buildings with radiated heat and airborne flying embers Signup and view all the answers

How should firefighters be protected from collapse dangers in a burning place of worship?

Using aerial master streams from safe areas Signup and view all the answers

What strategy is recommended for fighting fires in places of worship?

Using large amounts of water and high-pressure streams with maximum reach while addressing unique hazards and emotional factors associated with these buildings. Signup and view all the answers

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.

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.

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Description

Test your knowledge of firefighting and truss identification with this quiz. Learn about the importance of early identification of trusses and the actions firefighters should take upon discovery.