Had the opportunity to cut the driver's front A-pillar of a 1998 Volvo C-70. That car is a two-door convertible. it is the older model C-70 from Volvo with the rag top. The new C-70 version is now a hardtop convertible.
Anyway, the A-pillar is a Boron structure. It has the typical multiple layers of Boron forming a roof pillar. What is interesting for rescuers however is that inside the hollow portion of the Boron A-pillar, I found a tubular Boron pipe.
The Boron pillar with the Boron pipe made it very difficult to cut through. The cutter struggled until it stressed the pillar steel enough for it to actually fracture. That is what generally happens with these Advanced Steels.
I captured a few images to show...
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08-21-2011, 05:12 PM #1
Volvo A-Pillar with Boron Pipe Inside
08-21-2011, 05:14 PM #2
I took a shot looking right down into the cross-section of the Volvo A-pillar to show the detail and the fracturing of the Advanced Steel Boron metal....
08-21-2011, 05:16 PM #3
What you see as dark blue in the cross section image is the outside surfaces of the pillar itself. That is just mild steel.
The layer you see inside that is gray in color. That is an inner Boron layer. Remember, it is 8 times stronger than a layer of mild steel!
The round pipe you see inside that is 100% Boron.
08-21-2011, 07:25 PM #4
Wonder if SAWING it would be more efficient than "shearing" it. You'd need a Good blade. In any event,it's gonna take longer to do stuff. T.C.
08-21-2011, 08:53 PM #5
With the Advanced Steels, and Boron is just one of the types, you cannot saw through it with a reciprocating saw. It isn't the saw, it's the blade. When Boron forms the pillar, it goes beyond the capability of a saw blade.
When the blade begins to try to cut the pillar, it will cut into the outer mild steel but the teeth will just get smoked off when it gets through to the Boron layer.
The only saw that can cut through Boron is a rotary saw. The K-12 will go through it but that is not a practical tool for rescue of a trapped person. I also used two different 7 & 1/4-inch electric circular saws sold as rescue saws. They will eventually cut through Boron but the blade is destroyed, the noise is unbearable, sparks fly all over, and the saw will probably stall many, many times during the cutting effort.
08-21-2011, 09:57 PM #6
Have you tried the Diamond grit blades? Slow,but they should cut Boron OK. Still not seeing much of it around here so I haven't had as much chance to experiment as I would like. I've cut some pretty hard stuff with diamond blades. T.C.
08-22-2011, 03:09 AM #7
- Join Date
- Dec 2002
- Mainz, Germany
Good post. Renforcement pipes in roof posts are definitly a big concern for rescue crews. I can throw in some more graphics about the pipe in this specific vehicle, one from the Crash Recovery System, the other is a Volvo media image.
Both show that the pipe is running through the complete A-Post and is ending in the rocker panel.
Moditech Rescue Solutions B.V.
08-22-2011, 09:44 AM #8
08-22-2011, 12:37 PM #9
I just finished conducting two 'live' demonstrations in NY City for the IAFF. As part of the Redmond Symposium, I worked with three FDNY officers. We cut up a 2011 Chevy VOLT on Tuesday and then a second one on Wednesday. That makes a total of seven(7) 2011 VOLTs that I have cut up. I think it is an unofficial world record for one rescuer.
Anyway, the VOLT does not use Boron tubes but it does have Boron A-pillars and Boron B-pillars. They are big and resemble a box where they connect to the rocker.
The lesson I have learned cutting these new cars is that in order to roll the dash or jack the dash, the entire 'box' at the bottom of the A-pillar has to be completely cut through. I don't care what rescue tools you have. The steel will resist movement until it is completely cut and disconnected.
The Boron 'box' shape at the base of the B-pillar means that the "B-Pillar Blow Out" technique has to also be modified. One cut into the back side of the B-pillar will not allow the spreader to blow it out. You now have to cut at least three of the sides of the 'box' at the base of the B-pillar or it won't move when the spreader forces it.
08-22-2011, 12:44 PM #10
This is the driver's side of a 2010 Volvo XC60 that we cut open. It might not look like much, but that B-pillar and the rocker are all Boron steel. Realize that without a new generation power cutter, you would not be able to do what we did cutting this Boron steel.
You can see what I mean when I talk about the 'box' shape at the bottom of these newer pillars. Being all Boron, in order to remove the B-pillar, we had to cut the front edge, the inside edge, the rear edge, and the outside wall of the 'box' in order to get it to let go.
Look for 'boxes' in many of the new vehicles. This design does make the vehicle more crashworthy but when it does fail due to a severe impact, it will be more cutting for us.
08-22-2011, 04:48 PM #11
- Join Date
- Mar 2006
- Southern California
Ron, great post..... Like I've said earlier we cut on cars of all types of Makes and Models in Corona for (3) days. Mercedes Benz was awesome enough to donate 8+ brand new vehicles for us to use. The current use of these Advanced High Strength Steels are currently around 10.4% of the vehicle, however, the future holds that most vehicles will be up to 40+% AHSS which as we know is gonna make vehicles safer for the Occupants but way harder for Rescuers. The information I have says the tensile strength of Boron Steel is 150,000 lbs.
As far as cutting the Posts, we often forget that we can also cut the roof or use an Air Chisel for the outer layer. When we gave the update class from Corona to our FD we tried this and it worked well. Even Cutters with a small cutting area can cut the roof.
On the "A Post" you would cut approximately 1-2" above the Post into the roof. Obviously, you're gonna have to cut the windshield also so providing for Glass Management is critical.
On the "B Post" you take as large of a cut that you can that includes the Top Rail and as much material of the roof as possible. Even the older Amkus Combi-Tools can make these cuts (we had our Guys use the older/weaker tools to make the training more challenging).
For Rescuers that read these updates, Boron will most likely be our "Beast of Burden" when it comes to Auto X."Be LOUD, Be PROUD..... It just might save your can someday when goin' through an intersection!!!!!"
Life on the Truck (Quint) is good.....
Eat til you're sleepy..... Sleep til you're hungry..... And repeat.....
08-23-2011, 07:14 PM #12
I love Boron as our "Beast of Burden". It's so true!
09-21-2011, 12:17 AM #13
- Join Date
- Jan 2003
That same configuration was found in 07 Dodge minivanRescue Co. 1
09-21-2011, 08:52 AM #14
But NOT the same Hardness. T.C.
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