Improved Cutting Blades Enhance Rescue Tool Effectiveness

Many advancements were made during the past decade in fire apparatus, firefighting equipment, personal protective equipment and communications gear. But extrication toolmakers may have been confronted with the greatest challenge for improvements to keep up with the material and design changes in new vehicles.

Hydraulic rescue tool manufacturers and firefighters agree that changes in cutting blade technology, the introduction of single line hydraulics with quick-connect fittings, reductions in tool weights and the introduction of battery-operated units have led to significant increases in effectiveness.

Firefighters want to be able to set up their rescue systems quickly and efficiently, use the maximum amount of force when needed with as little strain as possible and have the tools perform without problems.

In essence, rescue tool operators want a bulletproof system. Manufacturers are striving to meet those needs by assessing feedback from the field and incorporating worthwhile critiques into new and redesigned products.

Fran Dunigan, marketing manager for Holmatro Inc. believes the most significant development in hydraulic rescue tools in the past ten years involves cutting blade modifications that improve “first bite” capability.

“The reinforced A and B posts in modern cars are more beefy and difficult to cut,” he said, pointing out that many hydraulic cutters more than 10 years old have difficulty slicing through them. For that reason, he said, Holmatro set out to redesign its cutter blade.

“We introduced our NCT blade, which is a significant improvement in cutting technology because we changed the geometery of the blade,” he said. “Firefighters can now more effectively cut the posts on the cars on the street today.”

With a hydraulic cutting tool, he said the highest cutting force is generally at the pivot point of the blades when they are wide open. But by changing the geometry of the cutting blade from a flat profile to a U shape, much like some hand-held wire cutters, he said Holmatro was able to increase cutting force, while using less pressure.

“As our NCT blade starts to close, it creates a teardrop that takes the material being cut and pulls it in closer to the highest cutting force area,” Dunigan said. “So now you have a cup or U-shaped blade that can make the same cut as a flatter blade, but use 40 percent less hydraulic pressure to do so.”

William Simmons, general manager at Hurst Jaws of Life, agreed that cutting blade improvements were necessary to keep pace with the stronger posts and materials used to build vehicles.

“We’re seeing new materials in car posts today that won’t collapse like in the past,” he said, “and we have to cut them from the widest position possible, which is a pretty significant change.”

He said Hurst designers changed their thinking about cutter blades, which typically focused more force near the pivot point of the blade.

“Instead of basing our view on the highest possible cutting force, we wanted to have the cutting force spread over a greater working area of the cutting blade,” Simmons said. “So we were able to design a cutting blade that allows the user to be able to cut material with more of the blade, rather than in only one specific area.”

Chuck Sheaffer, sales manager for Amkus Rescue Systems, said cutter blades have seen more design innovation and change than any other component of a hydraulic rescue system.

“It’s the blade in the case of the cutters or the tips on the end of the spreaders that can make all the difference in the world,” he said.

Rather than simply ratcheting up the power, he said, “We have a cutter body that uses different blades for different types of situations.”

Sheaffer said the length and design of the blade is where a tool gets its cutting power. “We can design the cutter to get more power at a different place within the cut,” he said, “whether the cutter tool is wide open, completely closed or somewhere in between.”

He noted that some manufacturers attempt to pull the metal being cut as much as possible toward the pivot point of the cutting blade. However, he said, with a 7-inch or 8-inch wide open cutter, the blade’s curve flattens out and doesn’t bring the metal back into the cutter as well as it should.

“Sometimes, the smaller blade actually will puncture better and get you into certain areas to suck the metal back into the cutter body,” he said. “Bigger isn’t always better, and stronger isn’t always the best.”

Todd Birkel, vice president of sales for TNT Rescue Systems, said cars have become much more difficult to dismantle because auto manufacturers added stronger and thinner materials such as boron and other low-alloy, high-strength steels to their vehicles, particularly in posts. To compensate, he said TNT developed bigger cutters with different blades.

“We have to come up with a stronger product to handle those new materials, but that correlates to a heavier tool to accomplish that task,” he said. “Those new materials lead to compression in cutting where the materials deform and make it more difficult to get through with the cutters.”

Very often, Birkel noted, a firefighter cuts through the outer layer of a reinforced A or B post only to be confronted by a rigid core.

In order to get through reinforced posts, TNT introduced three new cutters – the SLC 28 with 156,000 pounds of cutting force, the SLC 29 with 269,000 pounds of cutting force and the BFC 320 with 320,000 pounds of cutting force.

While TNT’s blades have retained their basic shape, Birkel said some have been modified to gain a mechanical advantage where needed.

“We’ve made some changes in the arcs of the blades to accommodate the larger C posts in cars, but primarily the shape is fairly close to what we’ve always had,” he said.

Hydraulic tool weight is a concern, Birkel said.

“To increase the power in a tool, you have to increase the size,” he said, “but there’s also ergonomic value to lightening tools across the board so they are easier to use. That’s been a primary focus for several years now.”

Tom Patton, president of Champion Rescue Tools, said vehicle structures have changed so dramatically that “the poor firefighter doesn’t stand a chance.”

So, he said he set out to build a cutter that would handle “anything on any vehicle in the next 20 years.” The new tool is called the Super Beast, and he said it was designed to cut safely with the ability to change cutter and spreader heads.

The Super Beast weighs 49.3 pounds and, according to Patton, puts out 500,000 pounds of force in the center of its pivot. He built a safety tether into his cutter blade so if it broke, the tether would keep pieces from separating and injuring a firefighter.

Single line hydraulics have made connecting rescue systems much easier, especially at night. From their inception, hydraulic rescue tools used twin lines – a pressure line to the tool and a return line to the pumping unit.

“Using twin lines in setting up a rescue system adds complication,” said Holmatro’s Dunigan. “It takes time to set it up, and it can be set up incorrectly. So we introduced the idea of a hose within a hose, meaning the firefighter can’t plug it in wrong and would no longer be exposed to pressurized hydraulics.”

The Holmatro single hydraulic line is called its CORE technology and uses male and female swivel couplings on each end.

“The single hydraulic hose with the end swivels means it’s more lightweight, it reduces space on the truck, it makes training error-proof, and on the scene you can’t hook it up wrong,” Dunigan said.

He noted that the female CORE coupler connected to the tool has an auto return valve in it so tools can be switched on the fly. The benefit, he said, is that a firefighter doesn’t have to run back to the pump and throw the dump valve to relieve pressure in the line in order to switch tools, as he would with dual hydraulic lines.

Hurst also has a single hydraulic line setup called Streamline, which gives the capability to hot swap tools without shutting the hydraulic system down for the changeover. Simmons pointed out that Streamline, available on all Hurst hydraulic tool products, can be retrofitted to existing equipment.

Birkel of TNT Rescue Systems agreed single line hydraulic systems offer efficiency and safety.

“The ability of the coupler to function as a valve so that you don’t have to disengage the pump and the simplicity in hooking up the systems certainly have garnered a lot of interest,” he said. “The single point connection is an improvement because it takes less time. You might save precious seconds in an extrication by only having to make that one connection.”

TNT offers both single and twin-point connection systems across all of its rescue tools, in both high and low-pressure systems.

Keeping the weight down on hydraulic rescue tools continues to be a focus for manufacturers because heavier tools cause firefighter fatigue.

Bruce Johnson, vice president of sales and marketing for Hurst, noted that the focus of many manufacturers is to make a tool that “day in and out is manageable in size, rather than one tool that can do everything.”

The goal, he added, is to produce a rescue tool that’s lighter in weight, without sacrificing operating capabilities, yet a tool that a firefighter can use for longer periods of time, get into tighter places and lift overhead to operate if need be.

Battalion Chief Bill Foss of the Golder Ranch Fire District in Oro Valley, Ariz., said some newer tools are nearly half the weight of older ones. Golder Ranch uses Hurst Jaws of Life rescue tools in both high and low-pressure systems.

“The difference between the two systems is not only in terms of the power, but also in the speed that the tool opens and closes,” Foss said. “You want a tool that responds to your touch and opens and closes quickly if you need that to happen. The newer tools close much faster on a post than the older ones.”

As an example, he pointed out that the C posts on most modern vehicles are much wider at the bottom than at the top.

“With the newer tools, you can close it quickly enough to crush the post and then whittle it down to cut it,” he said. “Also the hardened steel in the cutter blades cuts so much better than those in past years.”

Foss said he looks for good balance in a tool, one that is not front or back heavy, as well as speed in opening and closing the jaws or cutter blades.

“Being able to pick the tool up over your head or use it at chest level is very important,” he said, “so the tool that’s lighter in weight will allow you to work longer and more effectively.”

Another innovation in hydraulic rescue tools is the development of electro-hydraulic tools, essentially stand-alone rescue tools with self-contained hydraulic systems, each with its own reservoir, bladder and pump. These systems can be powered by either an onboard lithium ion battery or a 110-volt shore line. On a fire apparatus, they take up about half as much space as traditional hydraulic rescue tools with power plants and hoses. Hurst offers such a line with its eDraulic rescue tools.

Lt. Peter Walker of Lake Country Fire and Rescue in Chenequa, Wis., recalled he was at the scene of a recent accident and had a new eDraulic tool in the back of his vehicle. Walker is a Hurst distributor in Wisconsin.

“The car was wrapped broadside around a tree, the kind of thing no firefighter wants to see,” he said. “When the fire department arrived, they hooked up the truck’s hydraulics and were switching tools back and forth. I had the blind luck of having an eDraulic unit in my possession while driving by the accident.”

Walker offered the use of the Hurst tool and was pressed into service. He said he and other firefighters peeled off a door, stripped the roof and removed the dashboard.

“The unit didn’t hesitate going into second stage because there’s no distance between the pump and the spreader,” Walker said. “It blew off those hinges with no hesitation.”

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