Emergency lighting experts Command Light explain the fundamentals of scene lighting in fire trucks  

Numerous light studies show fire truck light masts provide more usable light than portable or truck-mounted lights. Even the most basic fundamentals back the advantages of elevated scene lighting. And yet, all too often, these masts are deemed an option. Rarely the standard. Still, they are an important choice that fire departments can make and advocate for when purchasing their apparatus, which brings us back to those fundamentals.   

There are three basic scene lighting principles, all backed by various light intensity findings, worth considering — clustering, elevation and placement.  

FUNDAMENTAL #1 — LIGHT CLUSTERING  

When it comes to nighttime vision, light uniformity (even lighting across the scene) is more important than intensity (extreme illumination of a particular area within a scene) because intensity can cause a breakdown of the eyes’ rhodopsin, a light-sensitive protein that activates the retina’s rod cells, which aid in nighttime vision. Moreover, this strain increases when a person’s eyes continually adjust from dim to bright lighting. This is where grouping lights on a light tower can be beneficial.   

Think of stadium lighting at your favorite sports arena. Much like a fire truck light mast, arena lights are clustered together to gather and direct light to create uniform lighting across the entire arena. The same holds true for the fire truck lighting.  Let’s compare a six-head tower to two different perimeter light scenarios. With perimeter lights, only half of the truck-mounted lights are directed at the scene, creating unlit areas and sub-par lighting. With the six-head tower, uniform lighting can be achieved. 

“The whole thing about lighting is to make sure it’s usable,” says Roger Weinmeister, President of Command Light, which manufactures light towers for departments around the globe. “The moment you fix lighting to the side of your truck is the moment you lose half the light, which is not a great investment given the expense of LEDs.”  

Meanwhile, light towers not only cluster these fixtures, Weinmeister adds, but they can be rotated and angled into endless positions to illuminate ditches, mountain slopes and other terrain. Some towers, like Command Light, offer backlighting capabilities to illuminate dual scenes.  

FUNDAMENTAL #2 – LIGHT ELEVATION  

Like the first fundamental, our second lighting principle builds on human anatomy.   

“Humans have evolved to work with the sun shining down from overhead,” explains Sam Massa, HiViz President and Chief Technologist for HiViz LED Lighting, a manufacturer of specialty scene lighting. “Here’s the science: Humans have two eyeballs, each recessed into a socket on the frontal bone of the skull. Above that socket, there is a bony structure called the supraorbital ridge over which the eyebrows typically align. When the sun shines down, this bony structure casts a shadow that typically occludes the eye, preventing the sun from shining directly into a person’s eyes as he or she works.”  

In short, our bodies, and more specifically our skulls, are built to mitigate this glare. However, at night, if the truck’s lights are fixed directly to the apparatus, all of this goes to the wayside. Massa stresses that it is important to select scene lighting options that will place fixtures high overhead to reduce this very glare.   

But how high is too high? The intensity of light decreases the farther it is away from an object. Light intensity findings can help you pinpoint optimal height. For example, through research we carried out, we found that a documented light tower produces 20 meters of usable light. This is achieved by elevating the cluster of lights 9 meters above the truck. Meanwhile, the telescopic mast raises the lights 10 meters high but only produces 15 meters of usable light, while the pole light kit had even less reach because the lights were not clustered together, stressing Fundamental #1.  

 

FUNDAMENTAL #3 — LIGHT PLACEMENT  

With light comes shadows, but shadows can often be avoided if a light is properly positioned. Take for instance a stepped pumper body. If a light is mounted above the pumper’s stepped ledge, the light’s optics will hit a portion of the ledge, which in turn will cast a shadow on the work area below. That’s where a light tower light Command Light comes in handy. This tower can be positioned to overhang on the side of the apparatus in a “streetlight” position.  

But the work area extends beyond the truck. Vehicles, property and even terrain, like ditches or ravines, are all work areas that have shadowed obstacles. However, when light is elevated, rotated and angled, these shadows can be managed, and there’s no better way to control the placement of light than with a mast.   

To test light intensity, we placed a vehicle roughly 10 meters from the apparatus light source. Here, both height and light angle impacted the amount of usable light inside the vehicle.   

This is a good point to talk about the difference between lux and lumens. Lumens is the total amount of light a fixture produces. However, this number does not represent lux — the amount of light that reaches the scene, or in this case inside the vehicle. As we’ve already addressed, a lot can factor in how many lumens make it to the fireground.  

“Every scene is different, so it’s important lighting is versatile,” Weinmeister concludes. “And when you have the ability to control light and how it’s grouped, placed and elevated, your apparatus will become an even more powerful tool.”  

And so, with a little urgency, light towers can be more than just an option. They can be a necessity.  

“When you’re out at night, saving lives and protecting property, there shouldn’t be a substitute,” Weinmeister says. “And just because it’s not the standard, departments can insist it become one.”