Advanced high-strength steel (AHSS) vehicle structures are helping to save the lives of occupants involved in crashes—but at the same time are making the lives of first responders much more difficult. Ron Moore, retired Division Chief of the McKinney (TX) Fire Department, has literally written the book on extrication involving vehicles with these advanced-steel structures, and he shared some of the challenges of this practice at the Great Designs in Steel seminar in Livonia, MI, this past May.
“As a responder, I can see cars that are pretty well mangled and when we arrive at the scene, the people are outside exchanging their insurance card with the law enforcement. Years ago, they would have been trapped and injured in that vehicle. So it is a good thing what the [advanced high-strength] steel is doing and the crashworthiness design, but on the other side of the coin, it is a challenge to us,” he said.
In 2008, Moore started to receive emails and phone calls from rescue personnel located all over the country about not being able to cut through A- and B-pillars and other structures with their department’s existing tools. “I have no idea what’s going on; it’s catching me off guard as well. Basically our extrication capabilities [were] outgunned by certain vehicles in certain areas,” he said.
Software providing schematics of different vehicles is commercially available to the fire service for about $600. In addition to showing battery placement, airbag locations, and other such data, the drawings also identify the usage of advanced high-strength steels, which Moore determined was the culprit in many of these queries.
Moore turned to manufacturers of hydraulic rescue tools in 2009 and found that none of their cutters worked with AHSS. Companies started working on prototypes and “over the course of a year, we wound up having about four manufacturers of these hydraulic rescue tools that were working right along with me literally redesigning the cutting tools to be this new generation specific to addressing advanced steel.”
In 2012, every manufacturer of hydraulic rescue tools has at least one specially designed AHSS-capable cutter that they can offer to a fire department, according to Moore. “It’s about a $5000 investment,” he said. “In many small communities that’s a chunk of change.”
Moore helped to develop “workaround” solutions for fire departments that cannot afford to purchase a new-generation cutter. For example, these rescuers are taught to seek out the “soft stuff” and make cuts in those locations, or to use a hydraulic piston ram to bend the metal at seams and welds rather than cutting through it.
“Most fire departments cannot cut structural steel in a car that is above mild-strength,” he said. “When you get into the 780, 880, 980, the 1000 [MPa], it’s off the chart as far as a typical fire department for its rescue capabilities unless they’ve invested in the newer generation of tools that will now allow us to go through even the toughest stuff that you’ve got to date.”
Asked about challenges with other materials such as composites, Moore said that AHSS provides the biggest challenge because “it’s in Main Street, USA vehicles; it’s in every community.” Other metals and non-metal materials do not issue near the challenge, mainly because they are not as prevalent.
Education is the most important strategy at this point. “If we know where the strong points are and where the existing non-advanced high-strength steel areas are, we can work our techniques to address the softer or weaker spots,” he said. “Chances are where you have placed advanced high-strength steel, that’s where we need to work because it’s protecting the occupant.”
Another challenge to Moore and other rescue instructors is getting their hands on enough vehicles with AHSS for fire departments to get the proper instruction. “I need a way to get a hold of new vehicles with new structure design that we can work with,” he said. “The crash test vehicles, [insurance institutes and other companies] want the money back from them for salvage, so they don’t part with them. Yet they would be prime for us for research.”