Crash Safety Stuff

Something to digest while you are hunkered down by COVID19.

This is Dr. John Melvin, one of my former Profs.

Some good tidbits of crash safety info here. He really pioneered the crash safety of modern racing.

Hope you enjoy.

Walt.

 

Most people won't know this but Dr. Melvin and others spent years researching the injury mechanisms within the human body.

What causes harm? Where do your organs move in response to G-impacts? Where does your brain go, and how are DAI [Diffuse Axonal Injury] brain injuries triggered?

The four key take-away points are these..........

1) Decouple the human from the rigid structure of the vehicle to avoid excessive impact G's being imparted into the body. Or at least employ an abundance of energy absorbing material between same. 2) Build a seat [or survival capsule] around the driver and use it to dissipate the impact inertia inside the perimeter of the roll cage. 3) Support the head, shoulders, and pelvis. All at once, all the time, laterally and rearward. 4) Use a HNR [Head Neck Restraint] together with a 6-point [or 7-point] safety harness to control forward impact loads.

This stuff saves lives and avoids serious injuries. It is not something to pass off lightly.

 

I will add to this post upon reflection....... Okay my day job involves a lot of this kind of stuff, so bear with me.

You can't just go out and buy a Racetech or Momo seat out of a catalogue and expect it to properly protect you fully. Kind of like going to a mall and buying a new suit. Does it fit proper? Well sort of, but that's all they offered on the rack.

It [driver containment system] has to be properly proportioned to "you".

If not, you could actually be doing yourself more harm than good. I can't say this strongly enough.

If you are building or retrofitting a race car, take the time and get the professional advice to construct a survival cocoon around yourself.

Be mindful of where safety personnel might need access to cut your sorry ass out, and give them clearance to do that. Ideally, could they cut out your capsule, with you in it, and transport you with it to a hospital if you are seriously compromised?

You don't really want to be a test dummy for a 50-140 G impact.

 

In case anyone wonders, yes I do own a Pro Mod. It is in the process of being re-framed and seriously updated [re-purposed].

I liked the visibility and posture when I first initially sat in it, but later I thought about the crash-worthiness and driver protection, and I said to myself "are you kidding me?. This was a name brand chassis offering, so not some piece of junk.

My suggestion to you all is this.........

Spend a few hours, nights, weeks, imagining what might possibly go wrong with your ride. How is your body being held by the combination of seat/belts/limiters? Even if you are in a door car, where can your appendages fling and what might they hit? Think "Indy Car" tub, and then extrapolate from there.

All the best to everyone. Maybe one day we can all return to racing, whatever that may look like in the hopeful future.

 

If you devise and build a cutting away plan, then please put yellow tape on those critical spots/tubes. Of course they will have to improvise on site.

This would seriously help rescue personnel. Go greet the rescue personnel if you can in advance. Say Hi and get to know them. Walk the track. Show them your ride. Can't hurt. What did that cost, nothing! Would it give you some peace of mind? Probably.

 

Have you seen the new McCamis video on the pro mod safety updates ? He does address these issues and explains some Safety Safari extrication procedures .

 

A good seat should be a priority. We have all been running GARBAGE seats forever, a carbon panel against tubing even with a poured insert is garbage. Most poured inserts are too thin in the critical areas to do anything.

 

Notice in this video (a real crash at 260 mph, without a hard impact, at Bonneville) and the complete lack of shoulder lateral support for the driver, and what that does to the lateral forces then imparted into the helmet/head/neck combo at the top of the driver.

Your helmet and head weigh on average say 13 pounds, or more. Good idea to constrain that mass. Agreed.

Your seat likely (if done proper) will constrain your pelvis. Agreed.

Your body structure from pelvis to neck has much more mass, and it is going to go want in the vector of impact. If it does, it can totally negate your head constraint efforts, or even make them worse from the perspective of your neck and spinal cord and brain.

I have said this before, but I will repeat it again. Dr. Melvin has been saying it for years. RIP.

Support the pelvis, shoulders, and head, all in line, all at the same time, both laterally and rearward. Use the head/neck device to constrain your head/helmet/neck combo in the forward direction only.