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Aerial Safety: An Engineer’s Perspective

Issue 4 and Volume 19.

In a recent incident, a firefighter fell off of an aerial device platform but managed to grab onto a tree on his way down.

Although this firefighter was not injured, his experience should be a reminder to us all that working on or around any aerial device requires training and special attention to stay safe.

All of us use products every day that are designed by engineers. Most products fall into one of three classes. Consumer products like dishwashers, blow dryers, and vacuum cleaners are designed to be used out of the box by anyone. Lawnmowers, snow blowers, and power tools have the expectation that the user will read the instructions and use the product in a safe manner with the proper protective gear. Industrial equipment such as construction equipment, airplanes, and fire apparatus are designed to be used by knowledgeable, trained, experienced, and skilled operators only.

Engineers approach the design of each class of product differently, and there is a different level of user involvement in each design. Although the consumer has no direct influence on the design of a vacuum cleaner, the purchaser of a commercial aircraft or a fire apparatus is intimately involved in the final design’s specification. The line between each of these classes of products is critical to keep in mind-both for the design engineer and the operator. Fire apparatus fall solidly into the industrial equipment class, and it is essential that we do not allow ourselves to think otherwise.

Industrial Design Challenges

When approaching the design of industrial products, the engineer is challenged with providing extreme capabilities. Aerial device design is similar to designing aircraft in the sense that the old engineer’s adage of “When in doubt, build it stout out of things you know about” does not apply. The easiest way to make something more stout is to add more material. When you add material to an aerial, you are adding weight. As you add weight to one section, the stress in the sections below it increases, and the device becomes less stable. To gain stability back, you must increase the stabilizer spread and add more counterweight. Aerial design is a constant tradeoff between strength and weight. It is this precise design requirement that drives the expectation that operators will adhere to four fundamental precepts: knowledge, skill, safe practices, and prevention.

Know Your Aerial Device

Knowledge is something you can gain by study, and this is exactly what is necessary before you ever touch your aerial device’s controls. Control functions, interlocks, and load capabilities may vary widely from one device to the next-even within the same manufacturer.

When I studied for my pilot’s license, I was expected to know more than just how the controls work. I needed to prove my understanding of the airplane’s detailed design. I needed to know how the pedal cables controlled the rudder and what to do if they broke. I needed to know how to load the plane properly, how to calculate the center of gravity, and how the plane would respond if the load fell outside the design limits. Just like a pilot is ultimately responsible for the safe operation of his plane, an aerial device operator is ultimately responsible for the safe operation of his device. This means understanding every function, every feature, and every limitation. It also means understanding the maintenance and inspection criteria, what will happen if something breaks, and how to respond.

What this means for the aerial operator is that the load chart is more than just a friendly suggestion. Every aerial operator must thoroughly understand the load chart for his aerial device. Operators must consider anything that can add load to the device. Water monitor reaction, swaying, snow or ice buildup, wind, and heavy personnel all must be considered-particularly when the device is near its operational limits. The device will work well and safely within its design limits, but the operator must know and stay within these limits at all times.

Practice Makes Perfect

If you ever watch a construction equipment operator working a front-end loader or a backhoe, you get the sense that the claw or the bucket is almost an extension of his own body. This massive piece of machinery can perform amazingly delicate maneuvers with loads that are measured in tons. The reason the equipment operates so smoothly is because the operator is skilled. He operates the equipment every day and has become skilled through practice, practice, and more practice.

The principle of practice, of course, applies equally to the operation of an aerial device. Whether operating a water tower or a heavy-duty platform, you will not gain the necessary skill without practice. The muscle memory needed to skillfully maneuver a ladder or platform during rescue operations does not come just from reading a book; it only happens by performing the actions properly over and over again.

Safe Practices

With study, you will know the right things to do. And with practice, you will gain the skills to perform them smoothly. The next precept is to develop the discipline to always adhere to safe practices.

The first line of defense in keeping people safe on the fireground is using personal protective equipment (PPE). When working on an aerial device, this must include a ladder belt or safety harness. National Fire Protection Association (NFPA) 1983, Standard on Life Safety Rope and Equipment for Emergency Services, provides requirements for ladder belts and specifies that the tether cannot exceed 24 inches. A short belt means that, if clipped to a sturdy object, the wearer cannot fall very far. This does not guarantee that a fall will not injure or even kill. But in the judgment of the experts, it will greatly reduce the risk.

With your ladder belt and tether in place, it is important to develop good disciplines for using them. The Fire Apparatus Manufacturers’ Association (FAMA) and the NFPA recommend that you be tethered to a sturdy structural feature on the device any time the device is in motion and whenever you are off the ground unless you are actively climbing or descending the ladder or you are entering or exiting the platform.

The second line of defense is to never go it alone. Although the primary operator should always be at the control station at the base of the device, other personnel are equally important. It may be necessary to have one or two spotters on the ground, especially while operating in tight quarters or around power lines. The spotters and the operator must practice together, perfecting a system of communication that will minimize confusion.

Another reason operating an aerial device is a team activity has to do with the need for a buddy. Climbing alone is like swimming alone-if you get in trouble, you will need help. If you fall and dangle from your ladder belt or safety harness, you may not have the strength to recover. If you dangle for more than a few minutes, your blood circulation may cut off and you may soon die.

The third line of defense is to apply the knowledge you have gained to react to things that might go wrong. If you understand your ladder, you can avoid damage to the device or harm to others. Heat, flames, and smoke are all hazards that can change at a moment’s notice, and you must be alert to get personnel out of the way if the situation warrants.

Prevention: Worth a Pound of Cure

Before every flight, a pilot will walk completely around the plane; feel the edge of the propeller for nicks; and look for damage, leaks, or other signs of problems. Your aerial device is a complex machine that requires the same care before it is used. Study your operator and maintenance manuals and NFPA 1911, Standard for the Inspection, Maintenance, Testing, and Retirement of In-Service Automotive Fire Apparatus, to determine the critical points on the device that should be regularly inspected. Inspect these points and look for signs of wear, corrosion, or impending failure. Once you know the inspection criteria, you should make sure your device certifications are up to date before agreeing to operate it. Just like no one would expect a pilot to fly passengers in a plane that has not met the maintenance plan, you should not operate your aerial device without the proper inspections.

FAMA’s Commitment

Our mission at FAMA is to enhance the quality of the emergency services community through the manufacture and sale of safe, efficient emergency response vehicles and equipment. Our focus on apparatus and aerial device safety is reflected in the soon-to-be published “Fire Apparatus Safety Guide.” This guide will be a must-read for every firefighter and will contain detailed information on ways to stay safe when operating an aerial device.

Finally, we all care about the safety of our firefighters and those they serve. Our industry is a small one compared to many others and, in most cases, answers to questions are only a phone call or an e-mail away. Our apparatus are designed to be used for tremendous good when cared for properly and used safely by knowledgeable and skilled operators. It is all of our responsibility to operate them only in that manner.

ROGER LACKORE is the director of product safety for Oshkosh Corporation. He has a bachelor of science degree in mechanical engineering and a master’s degree in engineering management. He is licensed as a professional engineer and a certified safety professional. Lackore has 27 years of design experience in the heavy vehicle industry.