NFPA D/O Apparatus flashcards

32 cards. Read the term and the definition here. The deck at the top of this page is optional.

NFPA 1911

Standard governing inspection, maintenance, testing, and retirement of in-service fire apparatus. It sets minimum daily, weekly, annual, and periodic check requirements and the records that must be kept.

Annual pump service test

Run 20 minutes at rated capacity, 10 minutes at 70 percent capacity with 150 psi net, and 10 minutes at 50 percent capacity with 250 psi net, recording all readings.

Steering axle tire tread

Tires on the steering axle of fire apparatus must be replaced when tread depth falls below 4/32 inch; tires on all other axles are replaced below 2/32 inch.

Aerial load test interval

An aerial device receives an annual inspection and test, plus a structural load test at least every five years. All results are documented and retained for the apparatus service life.

Out-of-service documentation

A defect affecting brakes, steering, tires, pump, or aerial integrity requires the apparatus be tagged out of service and the condition recorded on a work order until repaired and signed off.

Total stopping distance

The sum of perception distance, reaction distance, brake-lag distance, and effective braking distance. It grows with speed, and braking distance grows with the square of speed.

Apparatus following distance rule

Allow one second per ten feet of apparatus length plus one second, and add another second whenever speed exceeds 40 mph.

Engine brake on slippery roads

Exhaust and compression brakes are switched off on wet, icy, or snow-covered pavement because drive-wheel lockup can cause a sudden loss of control or jackknife.

Tire blowout response

Grip the steering wheel firmly, hold the apparatus straight, release the accelerator, and avoid hard braking until speed is reduced and control is regained.

Railroad crossing procedure

Stop the apparatus when required, open the window, look and listen in both directions, and cross only when clear. Never stop or shift on the tracks.

Collapse zone distance

Keep all personnel and apparatus at least a distance equal to the height of the involved building, and increase that zone for unsupported walls or heavy contents.

Ground ladder angle

Set the ladder base one foot from the wall for every four feet of working height, producing roughly a 75-degree angle for safe climbing and load capacity.

Outrigger placement

Fully extend outriggers on firm, level ground. Never place them over basements, vaults, septic tanks, or manhole covers where the ground can fail.

Overhead line clearance

Keep apparatus, aerials, ladders, and water streams at least 10 feet from energized overhead lines, increasing the distance as voltage increases, and treat all downed lines as energized.

Pump discharge pressure formula

PDP equals nozzle pressure plus total friction loss plus elevation change plus appliance loss. Add 0.5 psi per foot of rise and subtract 0.5 psi per foot of drop.

Friction loss formula

FL equals C times Q squared times L, where C is the hose coefficient, Q is flow in hundreds of gpm, and L is hose length in hundreds of feet.

Hose friction loss coefficients

With flow in hundreds of gpm, C values are 15.5 for 1 3/4-inch hose, 2 for 2 1/2-inch, 0.8 for 3-inch, 0.2 for 4-inch, and 0.08 for 5-inch.

Rated pump capacity test

A fire pump must deliver 100 percent of rated capacity at 150 psi, 70 percent at 200 psi, and 50 percent at 250 psi during the rated capacity test.

Cavitation causes

Insufficient water supply, excessive lift, a clogged strainer, or an air leak in the intake produces a rattling pump, fluctuating gauge readings, and lost capacity.

Maximum theoretical lift

Atmospheric pressure limits drafting lift to about 33.9 feet at sea level. Practical lift is 20 to 25 feet and decreases with altitude, hose wear, and intake restrictions.

Forward lay

The engine stops at the hydrant, lays supply hose from the hydrant to the fire scene, and is then supplied by that hydrant while pumping to the fire.

Reverse lay

The engine stops at the fire scene and a supply line is laid from the scene back to the hydrant, where another pumper takes the hydrant and pumps forward.

Drafting strainer depth

Keep the strainer at least 24 inches below the water surface and 12 to 24 inches off the bottom, and use a floating strainer in shallow or muddy water.

Water shuttle flow formula

Flow in gpm equals tank capacity in gallons multiplied by the number of tankers, divided by the round-trip cycle time in minutes.

Aerial load chart

The manufacturer's plate lists rated tip load and total load. Capacity decreases as the ladder extends and as the angle is lowered toward horizontal.

Aerial electrical clearance

Keep the aerial ladder, platform, and water stream at least 10 feet from energized lines, and increase that distance substantially for higher transmission voltages.

Master stream nozzle pressures

Master stream smooth-bore nozzles are designed for 80 psi nozzle pressure and fog master stream nozzles for 100 psi, per the nozzle standard.

Aerial emergency lowering

Auxiliary power or a manual bleed-down procedure retracts the aerial if the main hydraulic or electrical system fails. Operators must know and drill this procedure.

Due regard

Emergency vehicle operators may use warning lights and siren to obtain legal privileges but are never relieved of the duty to drive with due regard for others' safety.

Move Over law

Drivers approaching a stopped emergency or highway vehicle displaying warning lights must slow down and, when safe, change lanes to leave a buffer.

Two-in/two-out

At least two firefighters must be inside the structure and two outside, ready to rescue, before interior firefighting begins in an immediately dangerous to life and health atmosphere.

High-visibility apparel

Personnel working on or near a roadway must wear ANSI/ISEA 107 compliant high-visibility vests or garments so approaching traffic can see them.