|
|
|
Ladder |
a) A piece
of fire fighting apparatus that carries an aerial ladder used for rescue
and positioning of personnel on upper floors of a building. Also called
Truck or Aerial. b) Two rails or beams with steps or rungs spaced at
intervals; any fire department ladder of varying length, type, or
construction. |
|
Ladder bed |
The rack or
racks in which ladders are carried on a ladder truck. Do not confuse
with bed ladder. |
|
Ladder carry |
Any
organized system for carrying ladders. |
|
Ladder Company |
Also known as a truck company. A ladder company is a combination of a
fire truck with an aerial ladder, an assortment of ground ladders and
forced entry tools and the manpower used to staff it. Ladder trucks can
have straight aerial ladders as short as 65 feet or longer ladders with
platforms (buckets) on the end. In many department's ladder companies
are responsible for ventilation and forcible entry duties. A standard
ladder company will include an officer, driver/operator and two
firefighters on a ladder truck |
|
Ladder Fuels |
Fuels, such
as branches, shrubs or an understory layer of trees, which allow a fire
to spread from the ground to the canopy. |
|
Ladder locks |
Metal
devices used to hold the fly section of an extension ladder in place
after it has been extended. also dogs, pawls) |
|
Ladder pipe |
Master
stream nozzle mounted on the fly of an aerial ladder. |
|
Ladder Truck |
The ladder truck is referred to
as such because of its ability to carry a full compliment of ground ladders
as well as contains either a telescoping ladder or a platform. |
|
Laminated beam
|
Beam made of superimposed layers of similar
materiel (usually wood) by uniting them with glue under pressure. |
|
Laminated shingles |
Shingles that have added dimensionality
because of extra layers or tabs, giving a shake-like appearance. May also be
called "architectural shingles" or "three-dimensional shingles." |
|
Laminating |
Bonding together two or more layers of
materials. |
|
Lanai |
A verandah or porch. Landing A platform in a
flight of stairs. |
|
Landing |
A platform between flights of stairs or at
the termination of a flight of stairs. Often used when stairs change
direction. Normally no less than 3 ft. X 3 ft. square. |
|
Landing Zone |
See Heli-spot. |
|
Lap |
To cover the surface of one shingle or roll
with another. |
|
Lap joint
|
Joint produced by lapping and joining two
similar members. |
|
Large Diameter Hose |
The biggest hose used by firefighters, large diameter hose (LDH) is
sometimes referred to as a water main above ground. LDH is usually 4-5
inches in diameter and is used to supply water from the hydrant to pumper
trucks. See also supply hose. |
|
Latch |
A beveled metal tongue operated by a
spring-loaded knob or lever. The tongue's bevel lets you close the door and
engage the locking mechanism, if any, without using a key. Contrasts with
dead bolt. |
|
Latent heat of vaporization |
The quantity of heat absorbed by a substance when converted from a
liquid to a gas. |
|
Lath |
A building material of narrow wood, metal,
gypsum, or insulating board that is fastened to the frame of a building to
act as a base for plaster, shingles, or tiles. |
|
Lattice |
An open framework of criss-crossed wood or
metal strips that form regular, patterned spaces. |
|
Law of heat flow |
The natural
law that specifies that heat tends to flow from hot substances to cold
substances. This phenomenon is based on the supposition of the ability
of one substance to absorb heat from another substance. See Conduction,
Convection, and Radiation. |
|
Law of specific heat |
The measure of the heat-absorbing quality of a substance as measured in
BTU's or in kilojoules. The relative quantity of heat required raising
the temperature of substances or of the quantity of heat that must be
removed to cool a substance. |
|
Lay |
To lay hose
out in a predetermined sequence for fire fighting purposes. |
|
Laying a Line |
The evolution where a fire hose (line) is
advanced from a fire hydrant to the scene of a fire. An officer may say
"bring us in a line", which means he wants another company to perform the
above evolution |
|
Layout |
The distribution of hose at the scene of a
fire. |
|
LC50 |
Lethal concentration 50, median lethal
concentration. The concentration of a material in air that on the basis of
laboratory tests (respiratory route) is expected to kill 50% of a group of
test animals when administered as a single exposure in a specific time
period. |
|
LD 50 |
The dose of
a pesticide active ingredient taken by mouth or absorbed by the skin
which is expected to cause death in 50 percent of the test animals; the
lethal dose is measured in milligrams per kilogram of body weight.
Lethal dose 50. The single dose of a substance that causes death of 50%
of an animal population from exposure to the substance by any route
other than inhalation. |
|
Click here to return to top of this page |
|
Lead off |
Term that
indicates that hose is being laid from the hydrant to the engines on the
scene to provide water for fire fighting. Also referred to as Dropping
the Line or Laying a Line. |
|
Leader |
The ICS title for an individual
responsible for a Task Force, Strike Team, or functional Unit |
|
Leader Line |
A leader line is a line usually
having a gated wye on the end. Leader lines are usually 3 or 2.5 inches in
diameter and the wye usually feeds two or three 1.5 or 1.75 inch attack
lines. |
|
Lean to |
A shed whose rafters lean against another
building or other part of the same building. |
|
Ledger |
Strip of lumber fastened to the lower part of
a beam or girder on which notched joist are attached. The wooden perimeter
frame lumber member that bolts onto the face of a foundation wall and
supports the wood structural floor. |
|
LEL (Lower Explosive Limit) |
The lowest concentration of the material in air that can be detonated by
spark, shock or fire, etc. |
|
LEPC |
See
Local Emergency Planning Committee. |
|
Let in brace |
Nominal 1 inch-thick boards applied into
notched studs diagonally. Also, an "L" shaped, long (at 10') metal strap
that are installed by the framer at the rough stage to give support to an
exterior wall or wall corner. |
|
Level A Protection |
Type of protective clothing worn when the
highest level of skin, respiratory and eye protection against chemicals is
required. Generally, this consists of a totally encapsulating,
vapor-protective ensemble worn with a self-contained breathing apparatus
(SCBA) when the ambient environment presents both a respiratory and skin
contact IDLH hazard and impairs a worker's ability to escape. Originally
developed by the EPA, this definition subsequently has been adopted by OSHA
in HAZWOPER (29CFRI910.120). The level of protective equipment in situations
where the material is considered acutely vapor toxic to the skin and hazards
are unknown. Full encapsulation, airtight chemical suit with SCBA or SABA. |
|
Level B Protection |
Type of protective clothing worn when the
highest level of respiratory protection is required, but a lesser level of
skin protection is needed. Generally, this consists of a chemical liquid
splash protective suit worn with an SCBA when the ambient environment
presents an IDLH inhalation hazard, but does not present a skin contact
hazard nor does it impair a workers ability to escape. Originally developed
by the EPA, this definition subsequently has been adopted by OSHA in
HAZWOPER (29CFRI910.120). The level of protective equipment in situations
where the environment is not considered acutely vapor toxic to skin but may
cause respiratory effects. Chemical splash suit or full coverage non-air
tight chemical suit with SCBA or SABA. |
|
Level C Protection |
Type of protective clothing worn when the
concentrations and types of airborne substances are known and the criteria
for using air-purifying respirators are met (29CFRI 910.120). Generally,
this consists of a full-face or half-face respirator and hooded chemical
protective clothing. The level of protective equipment required to prevent
respiratory exposure but not to exclude possible skin contact. Chemical
splash suit with cartridge respirator. |
|
Level D Protection |
A work uniform offering minimal protection
and worn for nuisance contamination only. The level of protective equipment
required when the atmosphere contains no known hazard, when splashes,
immersions, inhalation, or contact with hazardous levels of any chemical is
precluded. Work uniform such as coveralls, boots, leather gloves, and
hardhat. |
|
Level 1 staging |
Used on all multiple-company emergency
responses. The first-arriving vehicles of each type proceed directly to the
scene, and the others stand by a block or two from the scene and await
orders. |
|
Level 2 staging |
Used on large-scale incidents where greater
alarm companies are responding. These companies are sent to a specified
location to await assignment. |
|
Liaison Officer (LNO) |
A member of the Command Staff responsible for coordinating with
representatives from cooperating and assisting agencies. The Liaison Officer
may have Assistants. |
|
Life line |
Rope used by firefighters in the performance
of rescue, search, and escape. |
|
Life net |
A canvas device with folding circular metal
frames with spring action. Used to catch persons who jump from buildings.
Not considered to be safe or effective for jumps made from above the fourth
floor of a building. |
|
Life Safety |
The first responsibility of the fire service
is the safety of lives and then the protection of property. This must always
be in the minds of the first fire company or unit to arrive; although, in
general, rescue and life safety are the duties of the ladder company. In the
vast majority of cases, even where the fire is severe and the need of rescue
of occupants is immediate, the most effective means of saving life is by
getting water on the fire and especially to deny fire the control of
vertical openings such as stairways and elevator shafts. |
|
Life safety code |
Guidance developed by the NFPA that is
concerned primarily with life safety in case of fire in buildings for
various occupancies. It addresses means of egress, signage, lighting, fire
control of egress routes, construction, as well as alarms and fire drills. |
|
Lift |
The vertical distance in feet between the
source of water and the pump of a fire department pumper. Water that is
drafted is often referred to as being lifted. Height a column of water may
be lifted in sufficient quantity to provide a reliable fire flow. Lift may
be raised through a hard suction hose to a pump, taking into consideration
the atmospheric pressure and friction loss within the hard suction hose.
Dependable lift is usually considered to be 14.7 feet (4.5 in). Maximum lift
is the height to which any amount of water may be raised through a hard
suction hose to a pump. Theoretical lift is the scientific height that a
column of water may be lifted by atmospheric pressure in a true vacuum. At
sea level, this height is 33.8 feet (10 in). The height will decrease as
elevation increases. |
|
Click here to return to top of this page |
|
Light Bar |
The unit that contains the strobe or flashing
lights found on the roofs of emergency vehicles. |
|
Light rescue vehicle |
Small rescue vehicle usually built on a 1 ton
or 1 1/2 ton chassis; designed to handle only basic extrication and
life-support functions and carries only basic hand tools and small
equipment. |
|
Limit switch |
A safety control that automatically shuts off
a furnace if it gets too hot. Most also control blower cycles |
|
Line |
Usually refers to a line of hose; also
frequently used as in reference to a rope or lifeline. |
|
Lineal foot |
A unit of measure for lumber equal to 1 inch
thick by 12 inches wide by 12 inches long. Examples: 1" x 12" x 16' = 16
board feet, 2" x 12" x 16' = 32 board feet. |
|
Lined tank |
A tank with a lining applied in strips or
sections and fastened to the inside of the tank after the tank is
constructed. Rubber is the most commonly used lining in hazardous materials
service. Glass, lead, nickel, polyurethane, and polyvinyl chloride are also
used as linings. |
|
Linen hose |
Fire hose constructed of linen or flax fabric
without a rubber lining. |
|
Lintel |
A horizontal structural member that supports
the load over an opening such as a door or window. |
|
Liquified gases |
A gas that has been subjected to a sufficient
amount of pressure or low temperature to cause it to become a liquid. A gas
that is partially liquid at a temperature of 70 degree F (21 degrees C). |
|
Liquefied Petroleum Gas (LPG) |
Any material having a vapor pressure not
exceeding that allowed for commercial propane composed predominantly of the
following hydrocarbons, either by themselves or as mixtures: propane,
propylene, butane (normal butane or isobutane), or butylenes. |
|
Listed |
Usually indicates tested by the Underwriters'
Laboratories, Inc., or Factory Mutual System as having met minimum criteria
for the device tested. |
|
Liter |
The volume of one kilogram of water at 4
degrees C.; the metric unit of measure for fluids; one U. S. gallon equal
3.78 liters. |
|
Live
load |
Weight on a structure consisting of movable
objects & persons. On a flat roof, the maximum live load is 20 psf (pounds
per square foot) if the roof is 200 square feet or less. |
|
LNG |
Liquefied Natural Gas is natural gas that has
been converted to liquid form for ease of storage or transport. It is
odorless, colorless, non-corrosive, and non-toxic. When vaporized, it burns
only in concentrations of 5% to 15% when mixed with air. Neither LNG, nor
its vapor, can explode in an unconfined environment. |
|
Load bearing wall |
Wall designed to support the weight imposed
upon it from above. Includes all exterior walls and any interior wall that
is aligned above a support beam or girder. Normally, any wall that has a
double horizontal top plate. |
|
Loads |
Live load; the total of all moving and
variable loads that may be placed upon a building. Dead load; the weight of
all permanent, stationary construction included in a building. |
|
Local Emergency Planning Committee (LEPC) |
A committee
appointed by the State Emergency Response Commission, as required by SARA
Title III, to formulate a comprehensive emergency plan for its corresponding
geographical area. |
|
Local Government
|
A county, municipality, city,
town, township, local public authority, school district, special district,
intrastate district, council of governments (regardless of whether the
council of governments is incorporated as a nonprofit corporation under
State law), regional or interstate government entity, or agency or
instrumentality of a local government, an Indian tribe or authorized tribal
organization, or in Alaska a Native village or Alaska Regional Native
Corporation; a rural community, unincorporated town or village, or other
public entity. See Section 2 (10), Homeland Security Act of 2002, Pub. L.
107-296, 116 Stat. 2135 (2002). |
|
Log book |
See
Journal. |
|
Logistics |
Providing resources and other
services to support incident management. |
|
Logistics Section |
The
Section responsible for providing facilities, services, and materials for
the incident. |
|
Lookout |
A short wood bracket or cantilever that
supports an overhang portion of a roof. |
|
Loom up |
A column of smoke indicating the presence of
fire. |
|
Looped water main |
A water main arranged in a complete circuit
so water will be supplied to a given point from more than one direction.
Also called a grid system. |
|
Loose fitting facepiece |
A respiratory inlet covering that is designed
to form a partial seal with the face, does not cover the neck and shoulders,
and may or may not offer head protection against penetration. |
|
Click here to return to top of this page |
|
Louver |
Opening or slatted grillwork that allows
ventilation while providing protection from rain, sight, or light.
|
|
Low Explosive |
An explosive that has a reaction velocity of
less than 3300 ft/sec (1000 m/sec) |
|
Low Order Explosion |
A slow rate of pressure rise or low force
explosion characterized by a pushing or dislodging effect upon the confining
structure or container and short missile distances. |
|
Low pressure |
Inadequate volume or pressure of water as
indicated by a pressure drop when a pump attempts to supply hose streams
have too great a length or size. |
|
Low pressure container |
A container designed to withstand pressures
from 5 to 100 psi. |
|
Lower Explosive Limit [LEL] |
The lowest concentration of gas or vapor (% by volume in air) that burns
or explodes if an ignition source is present at ambient temperatures. The
lowest concentration of fuel vapor mix to support combustion. When the level
is below the lower explosive limit, it is termed too lean to burn. See
Flammable Limits. |
|
LPG (Liquified Petroleum Gas) |
Any one of several petroleum products such as
propane or butane stored under pressure as a liquid |
|
Lugging |
Condition that occurs when the throttle
application is greater than necessary for a given set of conditions; may
result in an excessive amount of carbon particles issuing from the exhaust,
oil dilution, and additional fuel consumption; can be eliminated by using a
lower gear and proper shifting techniques. |
|
Lumens |
Unit of measure for total light output. The
amount of light falling on a surface of one square foot. |
