Range Finders

By MIKE McGREAL JR.

After one of my fellow firefighters brought a new range finder to the campsite of a recent hunting trip, I started thinking about this technology and how it might be integrated into the fire service. The Wilmette (IL) Fire Department will be putting a new 95-foot rear-mount tower ladder into service soon; part of this process will involve crews driving around town and observing different buildings. I remember how frustrating it was to misjudge the distance to a building or home and have to take the ladder down and reposition the apparatus. I understand how stressful this is at a fire: Am I too far away or too close to the collapse zone? How far up the high-rise will the aerial ladder reach?

There are several applications for range finders. One is for judging the distance from the aerial apparatus to the target; this takes the guesswork out of setting up an aerial apparatus and would make spotting the apparatus faster and more accurate. Other applications include identifying accurate distances for hazmat incidents and collapse zones, from hydrants, and the lengths of attack or supply hoselays. Its applications for urban search and rescue (USAR) and wildland firefighting operations are endless.

Range finders are used in a number of commercial and military applications such as surveying, mapping, mining, target acquisition, and so on. Laser range finders calculate the distance to an object by bouncing a laser beam off that object and measuring the time it takes for the beam to reflect back. Models are accurate to within one yard and can measure distances to reflective targets up to nearly a mile away. Depending on the manufacturer and model, most laser range finders are lightweight and low-cost and can measure slope distance, inclination (slope percentage), and azimuth (the horizontal angle of the observer’s bearing in surveying measured clockwise from a referent direction, such as north). Range finders can also calculate horizontal and vertical distance, height, and missing line values. Some models are equipped with 7× optics, in-scope sata display, and a serial port that can be integrated with Bluetooth® wireless communications. However, for our purposes, we focused on the portable laser range finder used by hunters that had a maximum range of 300 yards and slope compensation. There are several affordable models on the market.

Photo by author.

The range finder has seen a number of technological advances over the past few years. Many models are lightweight, are easily operated with one hand, can measure through rain or snow, can see through nearby clutter, function well in low light, contain integrated optical magnification, and are 100-percent waterproof. Firefighter-friendly rubber armored shockproof body construction is also available in many hunting range finder models. Additionally, there have been recent vast improvements made to lens coatings, battery life, and information display.

TRIAL PHASE

Our evaluation was limited to a few models from various manufacturers. We went out and spotted several types of buildings, from single-family homes to nine-story high-rise apartment buildings. We found few limitations in regard to building construction. Whether the building was wood, brick, steel, or a wall of glass, the range finders were accurate. A few misreadings resulted in user error, but training and reviewing the user manual remedied the problems. During an alarm at a high-rise on a slightly overcast day, I ranged several floors from different angles. By walking the range finder up each floor just below the windowsills, I was able to accurately read each change in elevation. The homes in Wilmette are generally more than two stories and are set back 75 to 100 feet from the street, so we must rely on our quint to access the roofs. Ranging the peaks of roofs of single-family residences from the street was just as accurate. Judging distances to a fire hydrant necessitated that the user fix on an object near the hydrant or the hydrant itself.

Range finders are lightweight, accurate, and affordable; offer quick target acquisition and display; give readings in feet or yards; and take the guesswork out of judging distances. On the negative side, their accuracy may be affected by rain, fog, or heavy smoke conditions. They come in many shapes and sizes and have different ranges and performance characteristics, each with benefits and limitations. Information on range finders is readily available on the Internet, and manufacturers provide specifications as well as information on these applications and limitations.

Technology has its limitations and should not be a substitute for good, sound training practices. Range finders have as much of a place in our tool box as a spotting device, training aid, safety device, or any other tool a creative mind devises.

MIKE McGREAL JR. is a second-generation firefighter and a deputy chief for the Wilmette (IL) Fire Department, where he has served for 21 years. He has bachelor’s degrees in business and fire science management and is enrolled in the Executive Fire Officer Program at the National Fire Academy. McGreal is active with the Mutual Aid Box Alarm System Division 3 USAR team and is a dive master for the Division 3 Underwater Rescue and Recovery team.