Electronic Systems Make Aerials Smarter And Safer

An E-ONE HP100 aerial ladder platform in a training situation.
An E-ONE HP100 aerial ladder platform in a training situation.
The electronic control station in the bucket of a Pierce aerial platform.
The electronic control station in the bucket of a Pierce aerial platform.
Thirty percent of Rosenbauer's straight stick 75-foot aerials are equipped with a remote control operating package, which allows the ladder to be operated from either the pedestal (shown here) or the platform.
Thirty percent of Rosenbauer’s straight stick 75-foot aerials are equipped with a remote control operating package, which allows the ladder to be operated from either the pedestal (shown here) or the platform.

Technology is turning aerial apparatus into “smart” machines, able to sense proximity to obstacles, allow ladder travel at variable speeds, permit operation from remote locations and prohibit operation in unsafe situations.

And all those advancements are the result of the integration of microprocessors, sensors and electronic systems that look, see and translate data into useable information to assist firefighters operating the equipment. Some of those innovations have been grouped under a single term, electronic envelope control, which originated in Europe.

One of the biggest technological changes in recent years is variable speed control, according to Joe Hedges, aerial product manager at E-ONE in Ocala, Fla. For example, on E-ONE’s HP100, a 100-foot platform aerial, variable speed hydraulics control the speed of the bucket and where it’s positioned relative to the turntable. The farther the aerial is extended, the more the variable speed control slows its movement.

“Suitable platform speed depends on the position of the aerial,” Hedges said. “The benefit to variable speed control is that you get the platform to travel fast when it’s retracted and slower when it’s extended. If the platform is traveling fast when fully extended, that can get scary for firefighters on the platform.”

But the aerial’s extension isn’t the only consideration. Variable speed control, he said, also will allow an aerial to speed up if it is fully extended as long as it is close to the centerline of the vehicle.

“By having a computer control everything on the apparatus you can vary the functions based on the sensors in the system, from elevation to extension, joystick positions and creep mode,” he said.

Creep mode slows all functions down when an aerial gets close to a building or other obstruction, significantly reducing the aerial’s speed. The electronics feather the controls to prevent whipping, allowing a smoother start and stop to aerial movements and preventing jerking of the aerial due to a change in direction.

“With creep control,” Hedges said, “when you let go of the stick, the aerial stops immediately.”

Electronics also protect the apparatus cab and body from collisions by the aerial, he pointed out.

“Every manufacturer does it a little differently,” he said. “We set the aerial to stop approximately 8 to 10 inches away from an obstacle, and then you have to use a momentary switch to allow the aerial to move in, holding the switch down as you move in close. With some other makers, you just flip a switch (non-momentary), and you can get closer.”

Paul Christiansen, marketing director for Ferrara Fire Apparatus, Inc. in Holden, La., said dual position waterways are getting a lot of attention on aerials.

“On a straight stick ladder, with the dual position waterway, you can position the monitor at the tip of the ladder, or if you were going to go to rescue operations, position it at the tip of the next lowest fly section,” he said. “We can electrically actuate it from controls on the turntable, and the ladder can be either in raised or lowered condition, but it must be completely retracted.”

Ferrara’s aerial platforms also make use of a speed control switch at the platform to allow an operator, when getting close to a building, to shift to a slower speed and creep into proximity.

Ferrara, which builds about 75 percent of its aerials as straight sticks, also offers a retraction safety interlock on its ladders.

Safety Interlock

“On a straight stick, you don’t move the ladder when someone is out there, so the interlock prevents the ladder from retracting beyond where the next fly section is located,” Christiansen said.

Ferrara also has a safety interlock built into its ladders to prevent the boom from being lowered onto the truck, avoiding cab and body collisions.

Jim Salmi, chief executive officer for Crimson Fire in Lancaster, Pa., believes weight management in aerials will become a more significant issue. The revised National Fire Protection Association 1901 apparatus standard that took effect last year added 50 pounds per firefighter to the weight allowance in a vehicle. With an eight-person cab on an aerial, that means an additional 400 pounds on the front axle.

“The challenge is how we configure the vehicle to provide functionality in a rear-mount aerial knowing we now have more weight on the front axle,” Salmi said.

Typically, a front axle can take up to 24,000 pounds, while a tandem rear axle can handle about 60,000. So there’s a much tighter margin on the front axle, Salmi said, especially because a good portion of the weight of the ladder and platform on a rear-mount hangs over the front axle.

“That’s where the potential for envelope control products kick in,” Salmi said. The keys with envelope control, he noted, are not only in taking weight off the front axle, but also in understanding the capacities of the ladder in horizontal reach.

“The farther out you go horizontally, the more counterbalance you need on the truck,” he noted. “Envelope control limits how far out you are able to go horizontally, meaning you need less weight on the truck.”

Electronic envelope control originated in Europe where most aerial apparatus operations are vertical. But in the United States, Salmi said, “We often need horizontal reach instead of vertical reach, as in the case of suburban apartment buildings.”

Donley Frederickson, national sales manager for Rosenbauer in Lyons, S.D., said envelope control is used on his company’s Smart Aerial, available on 75-foot and 109-foot straight sticks and on 101-foot and 104-foot platforms (three- and four-section aerials, respectively). The four-section aerial allows Rosenbauer to shorten the truck by about five feet, he said.

“The Smart Aerial uses sensors that allow us to short-jack the aerial and still be able to rotate the ladder in 360 degrees of operation,” Frederickson said. The sensors will not allow the ladder to be operated beyond its stability capability without retracting the ladder or raising it to a safe position.

Self-Bedding Feature

The technology used by Rosenbauer also prevents the ladder from being set down on the cab, light bar or body of the truck. The company offers a self-bedding feature on its aerials, where the operator gets the aerial into proper position, flips a switch and the aerial beds itself.

While the 75-foot straight stick has always been Rosenbauer’s main product, Frederickson said many departments have been opting for the 109-foot platform recently.

“I attribute that to the functionality of the platform and its rescue capability,” he said. “It’s easier to work off a platform for rescue than off a straight stick.”

Thirty percent of Rosenbauer’s 75-foot straight-stick aerials go out the door with a remote control operating package on them, and a slightly smaller percentage on its platforms, according to Frederickson. The remote control units allow the aerial to be operated either from the pedestal or the platform.

Rosenbauer also offers a side-seat option on its rear-mount aerials, available on either side. The advantage, Frederickson said, is visibility, placing the operator farther back and in a more comfortable position that eases operation.

Tim Smits, national sales manager for Pierce Manufacturing, Inc. in Appleton, Wis., said his firm uses envelope control where the truck can be short-jacked on one side and retracted on the other.

“It’s a basic form of envelope control, but does not affect our horizontal reach,” he said. “In the past you always used the aerial on the opposite side of the short jack, but with envelope control, you can go to the short jack side, but at a higher angle. If you try to lower the ladder down horizontally, it would not allow it unless you retract the ladder somewhat.”

Smits said Pierce is the only aerial manufacturer offering a choice of steel or aluminum ladders.

“We see the difference in performance issues,” he said. “With our 100-foot aluminum ladder, we can flow 1,500 gpm with a short stabilizer stance. With steel, we have a wider stance and less water flow, but it’s capable of a larger waterway and has a higher wind loading rating – up to a 50-mph wind, while the aluminum is rated to a 35-mph wind.”

Mike Moore, Pierce’s director of strategic new product development and support, said Pierce’s newest 100-foot aluminum ladders need only a 12-foot outrigger spread.

“They only come out two feet on each side of the truck, so you can set up the aerial in less space than when you have an open cab door,” he pointed out.

Besides the narrowed jack spread, the Pierce 100-foot aluminum ladder’s waterway has been moved to the side of the device to avoid crushing the piping on a parapet. The ladder can be operated at minus 11.5 degrees below grade and can rotate 235 degrees around the truck without extending the ladder.

Looking to the future of pumps and tanks on aerial apparatus, Hedges of E-ONE doesn’t anticipate big changes.

“We don’t see any trends away from having a pump,” he said. “If there’s no pump, you can bring an aerial device into a department at lower cost, but then you need to staff it with additional manpower.”

Hedges said quints and aerials sporting pumps and tanks make up between two-thirds and three-quarters of the aerials that E-ONE produces in a year, with the majority of those units being quints. “Those numbers have been fairly consistent for the past five to ten years,” he said.

The popular quint is composed of five elements – hose storage, water capacity, storage for 85 feet of ground ladders, a pump and an aerial ladder.

Christiansen of Ferrara Fire Apparatus said the majority of aerials his company sells are quints. “Usually the departments buying quints are medium-sized departments,” he said, “while the big city departments usually run ladders or platforms without pumps. Those are the more traditional truck companies.”

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