|(1) Target control, popular in Europe, allows an operator to have the aerial memorize its route to a target, avoiding obstacles like trees and power lines, and then retrace the route if needed. A drawback to these systems is if a power line falls behind the aerial and the aerial tries to retrace its old route. (Photo courtesy of Pierce Manufacturing.)|
|(2) Rosenbauer’s Smart Aerial system of envelope control allows an aerial to be safely operated over a short jacked side of the vehicle. (Photo courtesy of Rosenbauer.)|
|(3) Rosenbauer’s platforms have a proximity sensing system that uses five sensors-three in front and one on each side. The inset shows a close-up of the sensor. (Photo courtesy of Rosenbauer.)|
|(4) Crimson Fire’s aerial apparatus are heavier than their European counterparts, often by as much as 20,000 pounds or more. (Photo courtesy of Crimson Fire.)|
Technology commonly used in European aerial apparatus is finding its way across the Atlantic to North American aerials, while technology and products designed and developed in the United States are making their way to Europe to be incorporated into fire apparatus there. Yet, there appears to be a limit to how much technology will be swapped back and forth, mainly because of the fundamental differences between the fire industry markets in Europe and the United States.
Jim Salmi, chief operating officer for Crimson Fire, says that in Europe most of the buildings are constructed of stone or masonry, so the source of fuel for a fire is different than in the United States, with more internal content involved and less external structure.
In addition, Salmi points to the width of roads and streets in Europe (narrow and often very tight), as well as road regulations that are much more restrictive in terms of weight carried, as other differentiators that affect the design and use of aerial apparatus in Europe. “In the United States, a 100-foot aerial might weigh in the 60,000- to 70,000-pound range, but in Europe that 100-footer might only weigh 40,000 pounds,” Salmi says. “In Europe, they do things to minimize the weight of fire vehicles and place trucks on smaller GVW (gross vehicle weight) vehicles.”
As a result, European-style aerials have designs “that optimize the strength-to-weight ratios,” Salmi says, “and in doing so sacrifice some of the capabilities allowed with more weight.”
Salmi notes that in contrast to the United States, most European aerials have no water tank, ground ladders, or hosebeds on them. “They’re more limited in their purpose and don’t try to accomplish all things, so they stay under the weight limit,” he says.
Controlling the Envelope
One of the European technologies most discussed in fire industry circles is envelope control, which controls the range of motion of an aerial device based on the loads and weight on it. “In most European designs, if you’re not able to extend the outriggers fully on the side you’re operating on, the technology limits the amount of the envelope in which you can work, based on the spread of the outriggers,” Salmi says. “The computerized controls will not allow you to operate the aerial beyond safe limits.”
Mike Harstad, aerial manager for Rosenbauer, says European aerials typically operate faster than what firefighters in the United States are accustomed to seeing and also are less focused on tip loads. “The United States market is kind of transfixed on a 500-pound live load, with buckets having 1,000-pound loads,” Harstad says. In Europe, he adds, when the bucket is in a certain position, the aerial’s computer calculates the load and allows more firefighters to be put into it.
Harstad says Rosenbauer is the only company in the United States “operating an aerial over a short jacked side without an override,” an operation he calls “incredibly common” in the European market. “All other aerials have an inborn safety switch that can allow less than 10 degrees rotation to the short jacked side of a truck.”
Rosenbauer’s programmed logic of envelope control (called Smart Aerial) continually performs live load calculating, Harstad points out, actively monitoring the load on the ladder through sensors on the ladder extensions, in the hydraulic cylinders, and in the outriggers. “As long as the aerial is in a safe parameter, we can sweep 180 degrees across the short jack side,” he says. Typically, he notes, that means the aerial would not be near full extension.
But, envelope control hasn’t caught on with some United States manufacturers. Tom Smeal, aerial product manager for Smeal Fire Apparatus Co., says that while the National Fire Protection Association (NFPA) allows envelope control in aerials, it didn’t adopt the European standard on the subject. And, current testing provided for in NFPA 1911, Standard for Inspection, Maintenance, Testing, and Retirement of In-Service Automotive Fire Apparatus, he says, does not address envelope control for aerials.
“What concerns us as manufacturers is that with envelope control you are controlling machines with electronic transducers and switches,” Smeal says. “The European standard requires quite a few redundancies to be built into the aerial. But in North America, those redundancies are not required.”
Although Smeal says his company uses some electronic controls, for instance from an elevated platform to the turntable, all the master controls are manual ones. “When you pull a lever on the master control station on our turntable, you’re pulling directly on a valve,” he says. “There are no electronics in the master control station.”
The advantage to manual rather than electronic control, Smeal points out, is that if the rig were to lose all electrical power on the turntable, the operator would still be able to operate the aerial through hydraulics.
In addition to digitally programmed speeds of high, medium, or low (creep mode), Smeal also offers a ramping feature on its aerials. The feature can be digitally set as to how fast the operator wants the aerial to move from no movement to full movement, preventing an abrupt change of dynamic stopping or starting.
Tim Smits, senior manager of national sales and product support for Pierce Manufacturing Inc., says that although Pierce now has envelope control technology on its aerial products, there have been a number of technological innovations developed in the United States and later exported to Europe. “Pierce was the first company to bring multiplexing to aerials,” Smits points out. “We also developed collision avoidance, auto stow, and automatically leveling stabilizers. We’ve been doing them for at least 15 years.”
Collision avoidance prevents the aerial from being lowered onto the cab or body of the vehicle. Auto stow allows an operator to bring the aerial within a certain distance from its cradle, push a button, and have the aerial center itself and lower into the boom support area.
Automatic stabilization uses a computerized program to level an aerial ladder or platform. “When you get to the scene, you run the stabilizers out, hit a button, and the truck sets itself up,” Smits says. “It automatically puts itself to level and takes any human error out of the procedure.”
In Europe, Smits says many aerials have a higher reach than their United States counterparts, but it’s more important there because many European buildings don’t have the standpipe systems large United States buildings do. In addition, in the United States, when faced with a fire up higher than 10 stories, most departments perform an interior attack, he says.
Vertical reach may be more important in Europe because of its tight streets and tall buildings, Smits points out, but in the United States, horizontal reach is a critical factor. “Many United States buildings are set back from the street perhaps 40 to 50 feet,” Smits notes, “and some even more. So, an aerial’s horizontal reach is very important.”
Hit the Target
Target control is a European technology that’s made some inroads in the United States, Smits says, but he believes it has some drawbacks. Target control allows an operator to have the aerial memorize its route to a target, avoiding obstacles like trees and power lines, and then retrace the route if needed.
“What if a power line falls behind the aerial and you try to retrace your old route?” Smits asks. “That could be a problem if you’re using target control. Technology can be good, but there’s something to be said for the KISS (keep it simple, stupid) system too.”
Salmi says that target control-also called motion repeat or auto repeat-is much more common on European aerials than on United States ladders and platforms, and so are collision contact systems.
Collision contact systems typically have sensors around the platform that prevent the basket from hitting a structure or other solid object. Salmi notes that such systems can be overridden because sometimes the operator might have to put the basket against a structure to make a rescue.
Harstad adds that the proximity sensing system on his company’s platforms detects a solid object within 18 inches of the bucket and stops the platform before a collision can happen. Rosenbauer uses three sensors placed across the front of the platform and one on each side. “These ultrasonic proximity sensors are so sensitive, they can detect a piece of paper,” Harstad says.
Aerial Water Flow
Harstad believes that the biggest technology that’s gone across the Atlantic is water flow. “Until recent years, it was very uncommon to see a waterway on a European aerial because they mainly use their aerials for rescue,” Harstad says. “But now it’s much more common to see a waterway at the tip over there.”
Salmi agrees and expands on the water theme. “In Europe, they try to be more efficient with their extinguishing fluids,” Salmi says. “In the United States, we have good water supply systems, but in Europe the water supply is at a lower volume. So they’ve invested a lot more energy in minimizing the amount of agent, whether it’s water, foam, or CAFS in fighting fires.”
ALAN M. PETRILLO is a Tucson, Arizona-based freelance writer and is a member of the Fire Apparatus & Emergency Equipment editorial advisory board. He served 22 years with the Verdoy (NY) Fire Department, including in the position of chief.