Skip to main content
NFPA Configuration:
Large Apparatus

Large Apparatus | Zone C – Lower Rear

  Show/Hide Requirements

NFPA Large Apparatus Lighting Requirements

This page provides a general overview of the Large Apparatus emergency warning light requirements of the “NFPA 1901 Standard for Automotive Fire Apparatus – 2016 Edition”. The NFPA 1901 standard defines a Large Apparatus as an apparatus that has a bumper-to-bumper length of 25 feet or more, or an apparatus that has the optical center of any optical warning device at greater than 8 feet above level ground.

Warning Zones

Rev 5/20

Each apparatus, 25 feet long or greater, is divided into eight (8) warning zones – four upper and four lower.

Modes of Operation

Calling for Right of Way: Apparatus responding to an emergency.
Blocking Right of Way: Apparatus at emergency scene. White light not permitted.

Permissible Colors

All colors must meet the SAE J578 color
specification for White, Red, Blue, and Amber.
The diagram at right shows which colors are
allowed in each zone.
Color Calling for Right of Way Blocking Right of Way
Red Any zone Any zone
Blue Any zone Any zone
Amber Any zone except A Any zone
White Any zone except C Not permitted

Flash Rate and Failure

The minimum flash rate allowed is 75 flashes per minute for any single optical source and 150 flashes per minute from all of the light sources visible at any data point (i.e., at least two warning lights are required in each zone). Failure of a lighting device should not leave a data point without a signal.

Light Energy Requirements for Apparatus–Values in Candela-Seconds per Minute

For vehicles 25 feet or longer: Light energy at each data point on the horizontal plane must be a minimum of 10K and 3.5K at +5o.

Midship Optical Warning Devices

A midship optical warning device shall be mounted on both the right and the left sides of the apparatus if the distance between the front and rear lower-level optical devices exceeds 25 ft (7.6 m) at the optical center. Additional midship optical warning devices shall be required, where necessary, to maintain a horizontal distance between the centers of adjacent lower-level optical warning devices of 25 ft (7.6 m) or less. The optical center of any midship mounted optical warning device shall be between 18 in. and 62 in. (460 mm and 1600 mm) above level ground.