fama forum SAM MASSA
Light Placement on Fire Apparatus
Every fire department has got one of them, or if they don’t, they know one of them: the person who knows every little model number and fact about every light fixture on the market.
He can tell you how many flashes per second, how many lumens, and the year the fixture was released. But, can he articulate where the optimal placement is to prevent blinding firefighters on the next emergency scene?
A variety of Fire Apparatus Manufacturers’ Association (FAMA) member companies manufacture technologies designed to help firefighters work more effectively after dark. Often, firefighters and lighting manufacturers alike get sidetracked with things like the number of LEDS; number of lumens; or, when specifying apparatus, the placement of other firefighting appliances on their apparatus that could obstruct scene lights so the fundamentals of a rock-solid scene lighting package get overlooked.
By keeping the following four fundamental principles in mind, your apparatus specifying committee can build a truck that not only looks sweet but also gives you an edge when you are out at night saving lives and protecting property.
The name of the game in working after dark is uniformity. The intensity is less important; the number of times the firefighter’s eyes have to transition from very bright light to very dim light is what causes strain on the operator. It is more important to have an even level of lighting around the vehicle and fire scene than it is to have one spot in particular extremely well lit. Consider installing a greater number of fixtures each with a lower intensity around the apparatus to create an even workspace. Many FAMA member companies can even draw your apparatus digitally before manufacturing to help you visualize how the beam patterns will perform.
Humans have evolved to work with the sun shining down from overhead. As such, leveraging the evolutionary science and biology of our species during spec writing is helpful in reducing glare on fire scenes.
Here’s the science: Humans have two eyeballs, each recessed into a socket on the frontal bone of the scull. Above that socket, there is a bony structure called the supraorbital ridge over which the eyebrows typically align. When the sun shines down on a human’s skull, this bony structure, coupled with the eyebrows and eyelashes, casts a shadow that typically occludes the eye and prevents the sun from shining directly in the eyes of people as they work.
When specifying a fire apparatus, firefighters should keep the basic biology of the human body in mind and specify scene lights that can be placed as high overhead as practicable, so that the personal protective equipment and natural shape of the human skull help naturally prevent glare from hitting the crews at night.
Lights can be placed high up on the body, on poles, or even on light towers to help reduce glare.
Light doesn’t bend! Think about fixture placement and the shadows that will be created when you select a mounting location! If you mount a scene light with asymmetric optics on the side of a stepped pumper body (say, on the vertical surface near where the hard suction may be attached), if the beam shines “down” and “out” from the fixture and a horizontal portion of the body is below it, a shadow will be cast along the edge of the body on the ground. In these situations, consider bringing the fixture out toward the edge of the apparatus to prevent these shadows from occurring. Light cannot bend around the profile of the truck—if it’s obstructed, you will have a shadow.
You’ve only got so much hose! The vast majority of the time, when operating off the fire apparatus at night, you will be tethered to the apparatus by a piece of hose. When writing a specification for scene lighting on a fire apparatus, consider the length of hose and the most frequent operating characteristics of the apparatus for scene lighting design. If the truck has 250 feet of crosslay, there is no need for scene lights than can shine 1,000 feet down the road. Focus on the areas you can reasonably expect to work in and supplement your scene lighting package with portable or battery-/generator-/extension-cord-powered fixtures for the “what if” situations.
Many FAMA member companies build products specifically designed for the fire apparatus industry. When designing an apparatus, reach out to the manufacturers of the equipment you are considering and invite them in to help guide your committee on fixture placement. For more general information about scene lighting, as well as a variety of other topics related to fire apparatus equipment, check out the FAMA buyers guides online at https://www.fama.org/fire-service-resources-list/.
FAMA is committed to the manufacture and sale of safe, efficient emergency response vehicles and equipment. FAMA urges fire departments to evaluate the full range of safety features offered by its member companies.
SAM MASSA is the president and chief technologist for HiViz LED Lighting, a manufacturer of specialty scene lighting equipment with a primary focus on the fire and emergency services market. He is a North Carolina firefighter, an emergency medical technician, and a representative for FAMA on the National Fire Protection Association (NFPA) 1901, Standard for Automotive Fire Apparatus, technical committee.