Book 29 Truck Manual Flashcards
Effective ventilation will accomplish four main objectives:
Save lives
Assist in firefighter access
Control horizontal spread of fire
Reduce the possibility of back draft or flash over
If the heat, smoke, and fire gases are not released, they will accumulate at the highest point of the structure and begin to bank down and spread laterally. This process is generally known as ______________
Mushrooming
The key to safe and effective roof ventilation is the knowledge of _____________________
Rafter type and rafter direction
On roofs sheathed with plywood, the “Head Cut” is made __________ to rafters
Perpendicular
single cut made through the roof decking, the same width as the chain saw blade
Kerf cut
Since the plywood normally used is 4’ x 8’ in size, a nailing block will usually be found every __ feet.
4
A ____________is a small triangular piece of roof covering (composition), which is removed from the roof to expose the roof sheathing.Used to determine ?
Plug Cut
Sheathing type and composition thickness
A _____________ is a light cut of the roof covering, usually composition only. It is used to facilitate the removal of multiple layers of roofing material (composition).
Score cut
A skim cut is a light cut made with the chain saw, cutting through the __________ and _______________
Roof covering and plywood sheathing
turbine-style ventilator is about _____ more effective when the turbine is spinning
30%
In a 45 Degree inspection hole When the saw makes contact with a rafter, roll over the rafter and continue the cut for approximately _______________
6 to 10 inches
The chain saw operator should cut a minimum of ______ dice cuts before the puller begins removing sheathing.
3
Cut ________ inches inside of the purlins to avoid hitting metal hangers.
4 to 6
conventional construction will utilize a minimum of ________ (and up to mill/timber construction).
2”x 4”s
A frame configuration of conventional construction, Rafters are usually ______ inches or larger and are usually ______ to ______ “on-center.”
AND up to ______ For “ steep pitched roofs”
2”x 6”
16” to 24”
36”
Metal gusset plates , The most common are ___ gauge steel plates with prongs that produce _____ inch penetration.
18; 3/8”
Eighteen- gauge “roof truss clips” may be found nailed to the bottom chord spaced ____ to ______ and top plate of interior walls
3 to 5 trusses
Newer roofs use _______ inch plywood as a decking instead of 1 x 4 inch or 1 x 6 inch space sheathing
3/8” or 1/2”
Bridge truss roofs are found on various types and sizes of commercial buildings primarily constructed during the _______________. Wooden truss members are built from ________inch lumber
1930s and 1940s ; 2” x 12 “
Straight sheathing was utilized prior to _____, and _______ sheathing was utilized after 1933.
1933; diagonal
With tied truss arch roofs, Tie rods are usually ______ in diameter, with turnbuckles are used below each arch member to ensure the arches do not push the exterior walls outward
5/8”
Wooden I Beam , may be constructed from _____ inch plywood or “chip-board” of the same thickness.
3/8”
In open web construction, The steel tube web members are prefabricated from ________ cold rolled steel tubing with the ends pressed flat into a semicircular shape with a hole punched through the end
1” to 2”
Open web bar joists, Top and bottom chords are usually made from ____ steel and web supports are solid ______ inch steel bar
1/8” ; 5/8”
In a lamella arch, when exposed to fire , total roof collapse may occur if fire removes more than ____ of the roof structure
20%
steel loses its tensile strength at ______ degrees F,
1000
In pre-33 URM Buildings, Parapet walls around the perimeter of a roof. Parapet walls can be ______above the roof line, and ______ or more if used as a facade on the front of a building.
3 feet
5 feet
After the ________ Earthquake of 1959 . A _______inch concrete bond-beam cap to be laid on top of lowered parapet walls along public ways and exits. -
Tehachapi;
4” to 6” inch
Kings row can be found every ______ rows on buildings
4-6
Long Beach Earthquake of 1933 ordinances:
- Exterior walls are required to be at least nine inches thick.
- Masonry walls are required to be reinforced with steel “rebar.”
- All joists and rafters are required to be anchored to exterior walls. This is usually
accomplished by bolting a “ledger board” to a masonry wall and attaching the joist and
rafters to the ledger board with metal hangers. - Cement utilized in the mortar.
- Diagonal roof sheathing.
Tehachapi Earthquake of 1959 ordinances :
- A four to six inch concrete bond-beam cap to be laid on top of lowered parapet walls along
public ways and exits. - Parapet walls should not be higher than 16 inches including the bond-beam cap, and most
importantly; - Exterior walls drilled at the roof rafter level and a steel anchor bar/rod installed every four
feet and attached to the existing roof rafter. This modification rendered the fire cut of the
roof rafter ineffective. The steel anchor bar/rods are secured to the exterior of the building
by a plate/nut combination that is known as “rafter tie plates.”
The Sylmar Earthquake of 1971 ordinances:
- Add steel bracing from parapet walls to roof structural members.
- Metal straps across the width of the roof and attached to opposing walls. The straps are usually 1/3 of the length of the building back from the front and rear walls.
- Remove the layers of composition and cover the sheathing with ½ inch plywood. This decking is then recovered with composition.
Metal straps on pre-33 roofs , can be found _____ from walls
3 to 4 feet
Depending on the particular method that is employed, “curtain” construction can be about ____ faster than conventional construction
60%
Compared to negative pressure ventilation, positive pressure ventilation is approximately ______ as effective at removing contaminants from a building
Twice
Positive pressure is most efficient when the exhaust opening (heat hole, window, door, etc.) is between
__________ to ____________the size of the entrance opening
3/4 ; 1 and 3/4
positive pressure has proven effective AGAINST winds (leeward to windward) of up to ___ mph; efficiency will be reduced accordingly.
25
When Blowers are used in series, the front blower can increase the capacity of blower A by approximately ______
10%
removing screens on windows prior to using these openings for ventilation purposes will increase the efficiency of these openings by at least ____
50%
A single 18” blower is adequate for an average _______sq ft single family
dwelling
2000
Concentrations of carbon monoxide can be found during overhaul from what range?
500 ppm - 1200 ppm
Limitations in the length and diameter of the winding drum restricts this type of elevator to ______ lifts and slow speeds
150 foot
hydraulic elevators use hydraulic power instead of cables and traction sheaves and are generally limited to
_____ story buildings
6
The equipment rooms for hydraulic elevators are normally located at the lower level of a building, but can be at any floor level or ___________feet away from the elevator shaft
50 to100
Larger than passenger elevators, freight elevators can be as large as ________________ and have a carrying capacity of up to ______
12’ X 14’
3 tons
Gib blocks are approximately ___________________ and are installed every ______ across the underside of the door panel.
3”W x 1”H x 1/2” Thick
18 inches
centrifugal force governor is provided on most elevators to guard against overspeeding (when a car travels in excess of _____ of top speed, the governor will activate a safety stop device).
20%
Mains in water lines, normally run beneath a street and parallel to a curb, can vary from __________ in size
2 to 72 inches
Service lines run between a main and a water meter, can vary from ___________
1/2 inch to 12 inches
Water meters are normally directly adjacent to shut-off valves and vary in size from ___________inches (inlet- outlet size).
1/2” to 10”
Compound meters are _____ or larger and are normally found directly adjacent to shut-off valves.
4” inches
Domestic water pressure at normally ____ to ____
40 to 80 psi
