Automotive advanced high-strength steels (AHSS) and ultra high-strength steels (UHSS) have changed many of the long-standing techniques and practices for auto body repair shops. The same is true for the fire and rescue professionals who often must create further damage to a vehicle in the service of saving lives at an accident site. Understanding how first responder extrication and rescue practices are changing to account for today’s modern steels can assist repair technicians with assessing damage and planning and executing repairs to modern vehicles which have been the subject of extrication modifications.
For the best perspective on how AHSS and UHSS are changing the way rescue personnel interact with vehicles when extrication is necessary, the Steel Market Development Institute (SMDI), a business unit of the American Iron and Steel Institute, works with an expert on the topic — Ron Moore. A former battalion chief in a suburban Dallas-Fort Worth fire department, Moore is a nationally-recognized expert on extrication. He’s the author of the widely used textbook “Vehicle Rescue and Extrication.” Additionally, Moore trains fire, rescue, EMS and law enforcement personnel across the nation on how to safely rescue and extricate drivers and passengers from vehicles of all kinds.
The basics of extrication are a constant, Moore explains: Rescue personnel need access to the people inside the vehicle, room to work on them in place if necessary and a path for safe removal of all involved. This can range from the standard “door job,” as it’s known in the fire rescue community, to removing instrument panels, roofs or pillars, forcing compartments open and more.
Where there’s been crushing, bending or folding of vehicle structures putting occupants at risk, rescue personnel can either move or remove those materials based on the requirements of the specific situation. The materials involved factor into this decision on the scene, as some tactics such as door frame spreading, which worked in the past with traditional steel body structures, may fail when advanced or ultra high-strength steels are involved.
Tougher vehicles, tougher opponents
In general, Moore calls modern AHSS-intensive vehicles a “tougher opponent” for rescue personnel thanks to the strength of the materials they’re now working against, often in a race against the clock. While the increasing crashworthiness of vehicles means fewer extrication jobs, the new strength of the materials they’re modifying means, “when they are trapped, we have more work to do.”
“It’s becoming the norm for side-impact collisions with people trapped inside to remove the B-pillar altogether, and increasingly we’re ‘making the car a convertible’ by taking off the roof,” he explained. In the past, spreaders could move B-pillars far enough out of the way for most access needs, but the strength built into modern AHSS-intensive B-pillars means they resist displacement to such a degree rescuers find it easier to cut through three sides and then use a spreader to bend it out of the way, if not remove it entirely.
Additionally, many traditional techniques involved “crush-then-cut” for components such as pillar assemblies. But with the advent of AHSS, crushing became so difficult to accomplish, techniques have evolved to either cut as-is or crush while cutting, if the available tools allow.
Also, the increased need for access to structural members for cutting or spreading means rescuers are increasingly removing the instrument panel entirely by “rolling” or “jacking the dash,” a process often including fender removal to allow full access to instrument panel assemblies.