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By Alan M. Petrillo

Yet today, TDAs continue to be used by many departments for a variety of reasons, including maneuverability, storage capacity, ground ladder carrying ability, and faster setup time at a fire scene.

Advantages

Tim Smits, senior sales manager of fleet management for Pierce Manufacturing Inc., says a TDA is one of the most versatile pieces of aerial apparatus in a fire department's arsenal of vehicles. "A TDA has excellent maneuverability, and with an experienced crew, there's virtually no place you can't take the TDA because of its fifth wheel articulation and the ability to steer the rear of the apparatus around obstacles," he says.

Often, the area covered by a TDA's ladder is greater than a department could achieve with a straight-frame rear-mount ladder. "Brevard County (FL) has a 100-foot Pierce TDA that they took out on a training scenario at a hotel property that had an enclosed garage in front of the structure," Smits says. "There was only a two-car-width area in front where you couldn't position a rear-mount, so they maneuvered their TDA in so they could cover the whole front of the structure. They parked the TDA in the center and were able to hit every floor and balcony, and when they tried it with the rear-mount backed in as close as it could get, they only could hit one quarter of the structure."

Dave Perkins, aerial specialist for E-ONE, points out that besides maneuverability, carrying larger complements of ground ladders and having more compartmentation are big advantages of a TDA compared with a straight-frame aerial ladder. "Maneuverability seems to be the biggest benefit of a TDA over even a single-axle straight-frame ladder," Perkins says, "but another thing we're seeing propel fire departments toward TDAs is they are more concerned about carrying more ground ladders. In addition, there's more cubic feet of compartmentation, so departments are able to use the TDA as a specialized truck company and have its hazmat or water rescue components on the vehicle."

Pete Hoherchak, aerial products manager for KME, agrees with Smits's and Perkins's assessments. "With a TDA, the purpose of steering from the rear is maneuverability where the vehicle is able to get around in tight city streets," Hoherchak says. "Where the tractor goes, the tiller can follow."

Compartmentation is another critical benefit of a TDA, he adds. "A typical rear-mount ladder has a minimum allowance of 2,500 pounds of equipment," Hoherchak notes. "On a TDA, it's the same minimum requirement by the National Fire Protection Association (NFPA), but most departments are able to put between 5,000 and 8,000 pounds of equipment on the vehicle because of the space available and the fact that the TDA can handle it."

On the ground ladder issue, Hoherchak says a typical straight-frame aerial ladder will carry 115 feet of ground ladders, while a TDA will easily carry more than 200 feet of ground ladders.

Disadvantages

Chuck Glagola, aerial sales manager for Smeal Fire Apparatus, notes that TDA disadvantages includ

Christian P. Koop

They all serve the same basic purpose: to assist the foundation brakes in stopping heavy ERVs and commercial over-the-road rigs. However, there are several different makes and types on the market, and how they are mounted and operate all differ. Impact to the rest of the vehicles' systems and reliability also differs as well as how much retardation output they can produce. In this article, I will briefly cover the history behind some of the different types of retarders we have used in my department and some of my experiences dealing with repairs and maintenance.

Because retarders provide added stopping power, they will also reduce the possibility of brake fade, which I am sure all will agree is huge when it comes to safety. Reducing or eliminating brake fade is the main reason they were invented. Keep in mind that they do a lot more than this because they not only improve or reduce stopping distances but also extend brake life. Extending brake life means cost savings and less time at the shop. Fewer changeouts (crews transferring their gear from a frontline ERV to a spare) is a good thing for the overall operation, the crews, and the communities they serve. These are two extremely important subjects, particularly in today's highly litigious environment not to mention tighter budgets. To reiterate and make sure I get my point across, retarders not only improve the safe operation of any ERV equipped with these devices, they will also reduce brake maintenance and replacement costs over the life of the ERV while reducing equipment downtime simultaneously.

There are several different types and makes of retarders on the market today, and they differ in operation; efficiency; cost; installation; and, most importantly, to me as far as the fire service goes, how much they can really slow the vehicle down in brake horsepower (BHP) at low-speed operation or intercity service and how quickly they achieve maximum retardation. They run the gamut-ranging from hydraulic transmission output retarders to electromagnetic driveline retarders and engine retarders.

Electromagnetic Induction Retarder

The first type I will cover is the electromagnetic induction retarder from Telma, which is probably the oldest, having been around for almost 70 years. It was developed by an engineer in Europe who saw the need to add a means of assisting brakes to reduce total brake failure because of brake fade. Heavy trucks would lose their brakes in mountainous regions of Europe, resulting in many lost lives and destruction of equipment and goods. These retarders can be mounted in the driveline hanging from the chassis rails or in a "focal mount," which bolts directly to the differential input housing. This retarder is totally frictionless, and the energy absorbed by these retarders is released directly to the air surrounding them.

In a nutshell, there are a set of fixed nonrotating electrical coils with two metal stators on either side that rotate with the driveline. As the electrical field generated in the coils is induced into the stator, it serves as a driveline brake and will slow and eventually almost bring the vehicle to a full stop. They generally are programmed to turn off or deactivate at a predetermined speed so they do not remain on when the vehicle is stopped. The units we had in se

A fire department's firefighters and officers are usually the best resources in deciding what course of action to take when it comes to a piece of apparatus that is on the edge of its useful life.

By Alan M. Petrillo

If the apparatus is getting old and needs repair, they have to decide what to do-refurbish the vehicle or buy a replacement. The decision isn't always as straightforward as it might appear. The types of departments that consider refurbishing vehicles vary, Jeff Wegner, vice president of sales for Smeal Fire Apparatus, points out, from large municipal departments refurbishing aerials and pumpers to smaller departments that might not be able to afford a new vehicle and choose to refurbish an existing one to get another 15 to 20 years out of it.

Wegner says that in 2009, when the economy took a nose dive and manufacturers suffered a 40 percent decrease in new truck sales, refurbishments became popular again. "We saw a lot of departments doing refurbishments then," he notes, "and that trend continued for several years. But, new truck sales are starting to come around, and there aren't as many refurbishments as in past years."

Donley Frederickson, national sales manager for Rosenbauer, believes that apparatus refurbishment work has slowed down, a sign he says means "fire departments are watching their finances pretty closely. But when there's too much work to be done on a vehicle, our dealers usually recommend that the fire department buy a new vehicle instead of going the refurbishment route."

Financial Considerations

Don Daemmrich, refurbishment center sales manager for Pierce Manufacturing Inc., believes that a great deal of refurbishment comes about because of finances. "I think a lot of the refurbishment that is done to fire vehicles is due to budgetary considerations in the fire department or municipality," Daemmrich says. "And often, a department that has a custom piece of apparatus it likes might want to update it with the latest safety technology."

Daemmrich says that larger city departments typically are the ones bringing in apparatus for refurbishment. "The bigger cities run a lot more calls, and road conditions might be more difficult, so their apparatus might need to be refurbished more quickly than a department that doesn't have such a high call volume," he notes. Daemmrich's rule of thumb on the value of refurbishment is, "If you can keep the refurbishment at 50 percent of the cost of a new vehicle, it's a good investment."

Chris Lashley, plant manager of the factory service center at E-ONE, agrees with Daemmrich's cost estimate. "If we see a customer exceeding a cost that shows it's not in its best interest, we advise that customer to consider buying a new vehicle," Lashley says. "We usually will consider going to 50 to 60 percent of replacement cost. Beyond that, it's better to replace." He says aerials and aircraft rescue and firefighting (ARFF) vehicles are typically the best candidates for refurbishing.

Mark Albright, general manager at 4 Guys Fire Trucks, agrees that the decision on whether or not to refurbish a vehicle is a tough call for fire departments. "How much money do they have to spend?" he asks. "A refurbish job can run well over $100,000 or more, but weighed against the cost of a new truck at $400,000, it might be more attractive. It depends on what the department can afford."

The cost of a new vehicle also drives some departments to refurbish an existing

By Bill Adams

Politically correct variants are "keep it short and simple" and "keep it simple and straightforward." Those acronyms should be applicable to fire apparatus purchasing in general and to specifications and standards in particular.

Disclaimer

The intent of this article is not to degrade, impugn, or criticize purchasers, apparatus manufacturers, or specification writers (spec writers). Writing fire apparatus purchasing specifications is a major responsibility. It is a demanding job, and I give credit to all who do it. There is no disparaging or passing judgment on the National Fire Protection Association (NFPA) 1901, Standard for Automotive Apparatus. The document is conspicuously referenced because all specifications are heavily influenced and governed by it. NFPA 1901 is the bible of fire apparatus purchasing-regardless of whether spec writers subscribe to its principles and philosophies. It's not going away. Live with it.

One objective when purchasing a new rig is to improve the vocation of firefighting. Any regulatory standard or specification making firefighters' work less hazardous and less complicated to perform is commendable. Specifications and regulatory standards should be as functional as the apparatus they intend to describe. Unfortunately, some regulatory requirements are confusing, hard to read, and harder to understand. As a result, writing effectual purchasing specs can be a challenge. Purchasing fire apparatus should not be a complicated process.

Education

Being unaware, uninformed, and unfamiliar does not necessarily mean one is ignorant or uneducated. Regardless of being career or volunteer, not all firefighters are as well versed in the technical aspects of writing specs as those who professionally write them and the standards that govern them. Infrequent exposure to spec writing and purchasing does not mean an apparatus purchasing committee (APC) lacks the skill or ability to buy a fire truck. Even experienced firefighters and APC members might need a little help. The industry should help them.

APC members can be intimidated, perplexed, and even confused by technospeak-technical jargon beyond their grasp. Some may be overwhelmed by a lack of clarity in the written word. Asking for clarification of specifications and standard verbiage is not an indication or admission of ignorance. Some APC members may refrain from asking too many questions for fear of appearing foolish. In my opinion, regulatory standards and specifications should be simplified and made easy to read. Doing so will make firefighters and (some) spec writers better educated and an APC's job less complicated.

Specs and Standards

Fire apparatus original equipment manufacturers (OEMs) publish standard specifications proprietary to their products. They use them to educate prospective customers and to promote their products. OEMs encourage purchasers to use them as purchasing specifications. That is their job. Although using proprietary specifications is questionable in some political arenas, it's a common practice, and most everyone does it. Get over it. I do not address the validity of proprietary specifications herein, but I do address making them and the regulations that govern them understandable and easy to read.

Historically, fire apparatus specifications were considered long if they exceeded a couple dozen pages. Thirty years ago, one manufacturer was ecstatic when his specification broke the 75-page mark. Today, specs for a simple pumper can easily exceed 100 pages. I question if they need to be that long. It is understandable if the intent of lengthening the document is to educate the consumer. It is debatable if they are lengthened