SUBJECT: Advanced Steel TOPIC: Extrication Challenges of Advanced Steel in Vehicles: Part 3 OBJECTIVE: The rescuer will understand and explain the capabilities and limitations of various manual-, air-, and electric-powered rescue tools. TASK: Given the information contained in Part 3 of...
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SUBJECT: Advanced Steel
TOPIC: Extrication Challenges of Advanced Steel in Vehicles: Part 3
OBJECTIVE: The rescuer will understand and explain the capabilities and limitations of various manual-, air-, and electric-powered rescue tools.
TASK: Given the information contained in Part 3 of this series and reference to a late-model passenger vehicle, the rescuer will be able to identify individual rescue tools within the department's tool inventory that can and cannot be expected to cut through advanced steel Boron structural areas.
During this first-ever research into the challenges of advanced steels for vehicle rescue, it became very apparent that there were rescue tools out there that did not have the capability to cut through advanced steel. Essentially, our current generation of cutting tools were being out-gunned by the strength of the new alloy steels such as Boron and Martensite. In Part 3 of this series, we begin exploring exactly which tools will cut advanced steels and which won't. The time to find out is now, not at the scene of a crash with people trapped.
The research into tool capabilities began by first taking rescue tools that could potentially be used for cutting vehicles apart and organizing them into specific categories. The categories selected were air chisel tools, electric sawing-type tools, gas-powered cutting tools, hand tools and power rescue system cutters. The plan called for each family of rescue tool to be evaluated in a systematic manner on confirmed advanced steel.
Engineers from the American Iron & Steel Institute who participated in this field work confirmed that Daimler-Chrysler had exactly the same advanced steel structure present in its Dodge Caliber four-door sedan as well as its Jeep Patriot and Compass SUVs. The structural A-pillar, the B-pillar, and the roof rail back to the C-pillar were confirmed to be made of hot-stamped Boron alloy steel; that's one of the ultra-high-strength steels that are giving our rescue tools problems. Armed with that information, the Learning & Development group at the corporate offices of State Farm Insurance became involved in supporting the project. Through their network of agents, State Farm officials were able to locate eight 2007 or 2008 models of these specific vehicles, five Calibers and three Jeeps. All had suffered some sort of collision damage, were assigned as "total loss" vehicles and were scheduled for salvage auctions around the country.
Armed with knowledge of exactly what steel was present in these specific vehicles, exactly where it could be found, how thick it was and even how it was attached to the rest of the vehicle, the next step was to plan some rescue tool testing. The outcome of the research had to show what the capability of our current rescue tools are and what tools exist that have the capability of cutting through the advanced steels. The steel that was going to be consistently encountered in all these vehicles was Boron; ranging in thickness from 0.889 mm to 1.9 mm. To put things in perspective, the Boron ranged from slightly thinner than a penny to slightly thicker than a quarter. Also, in every vehicle the Boron layer was an inner layer of steel either inside the A- or B-pillars or comprising a layer of the roof rail. The B-pillar is constructed of three layers of metal — two mild steel layers and the Boron.
Air Chisel Tools
Air-powered tools, both high and low pressure, were tested first. In every case, the air chisels or airgun tools were unable to cut through the Boron B-pillars. The chisel bits cut into the outer mild steel layer but were unable to cut through the Boron layer, even the thinnest areas. In several cases, the chisel bit actually broke. Air chisels are not advanced steel cutting tools.