Nasty NASA GTS crash at Putnam Park on the 19th...

[gt40]

This month seems to be bad for NASA events... This guy is lucky to be alive (http://www.corner-carvers.com/forums/showthread.php?t=38101)...

I think its time to re-evaluate not only our harnesses, but also the design of our cages. I know I will...

[GlennCMC70]

if anyone finds out what tube wall thinkness he used, please post it here.

[GlennCMC70]

compair these two pics. i want you to see why i added the bar just behind the side morrors in my car. the red car's cage bent at the A pillar bend at the knee bar. the bars in my cage would help resist that.
http://i237.photobucket.com/albums/ff9/RSCoupe/IMG_1427.jpg

[GlennCMC70]

http://www.lawmotorsports.net/Pics/Glenn/web/CMC70_build_03_700.jpg

[gt40]

if anyone finds out what tube wall thinkness he used, please post it here.According to the C-C.com thread, it's 1.750” x 0.120” DOM. I'll be adding similar supports to my cage, along with an additional support from the min hoop to the halo, right next to my head.

[mitchntx]

Not a thing wrong with those supports.

Just make sure you place them smartly so that the driver can get out of the car in a hurry if need be.

Fixing one problem that creates another doesn't solve anything.

[gt40]

Not a thing wrong with those supports.

Just make sure you place them smartly so that the driver can get out of the car in a hurry if need be.

Fixing one problem that creates another doesn't solve anything.Absolutely! Ingress and egress are important considerations for me (for obvious reasons!)

[AllZWay]

I wouldn't mind adding those bars to my cage.

They definitely would have helped in that crash, but it is really wierd how the tubing just buckled in the straight part....not the bent part.

[Rsmith350]

Yeah but if you read the story behind it that wasn't hit flat. that curved indention was were a tree hit.

[GlennCMC70]

even w/ the bars i'm refering to, the cage would have likely kinked where it did, but the A pillar bar wouldnt have layed down like it did. if you go to the link w/ all the pics on it, you will see alot of distortion to the A pillar bars at the knee bar area. mostly to the passenger side.
i also am rethinking the bar thats required in the T tops cars. having a center bar between the eyebrow bar and the top of the main hoop would add the 3rd bar that had to fail before it would have kinked.

i'll also consider adding tubes to the main hoop and A pillar bars to triangulate that opening.

[mitchntx]

From the CC thread ...


Has there ever been a thread about a race car crash on Corner-Carvers that didn't involve a bunch of you guys ripping on whatever cage was in it? I'm not saying you're wrong, I'm in no position to judge, but for some of you guys, it seems like no cage is ever good enough.

This guy's comment and the intent of the comment is spot on.

There is and always will be a point at which a cage will be breached or fail. Not all possibilities can be addressed because some remain untapped.

Monday morning quarter-backing is very easy after this kind of incident.

Bottom line? The cage did it's job. The driver is alive today.

[GlennCMC70]

i agree Mitch - cage allowed him to have a higher chance of survival.
i think the NASA CCR's and the CMC rules limit cage design way too much. there were several things i tried to get approval for w/ my cage and was shot down.

so take cage failures w/ a grain of salt. alot of times the builders hands are tied by rules.

i too have balanced safety w/ regards to a weight penalty. the cash we are talking about here is a very low percentage type crash. a side impact would be a high percentage impact.

[AllZWay]

From the CC thread ...


Has there ever been a thread about a race car crash on Corner-Carvers that didn't involve a bunch of you guys ripping on whatever cage was in it? I'm not saying you're wrong, I'm in no position to judge, but for some of you guys, it seems like no cage is ever good enough.

This guy's comment and the intent of the comment is spot on.

There is and always will be a point at which a cage will be breached or fail. Not all possibilities can be addressed because some remain untapped.

Monday morning quarter-backing is very easy after this kind of incident.

Bottom line? The cage did it's job. The driver is alive today.

Well... you know everyone is an expert about everything at CC.com and no one ever makes a mistake. :roll:

[gt40]

Bottom line? The cage did it's job. The driver is alive today.Just my opinion here, but the driver needs to buy a lottery ticet -- he was the luckiest SOB on the track that day. according to his own report on another forum (linked to in the C-C.com thread,) the roof was actually wedged between his helmet and his HANS Device, shoving his chin into his chest and cutting off his airway. Had it not been for the emergency crew getting out so quickly, he would have suffocated.

While technically the cage did do its job, it could have done it better, and isn't that what we're interested in? Most of us have a similar design in our cars and judging by how that cage deformed, I think we can improve on what we have.

[mitchntx]

Good points Robert.

I'm kind of hamstrung as I can't see the pics at work.

I'm not advocating NOT doing anything. But I certainly see a lot of "I told ya so" going on.

The only way I can see making it 100% safe is a coccoon of 1/4" plate completely surrounding the whole car ...

[jeffburch]

I read most of what's at cc.com.
Also there is a link to a gts forum where he blogged the build of the car.
On there is where the interesting stuff is.
He himself comments on why he went off.
Overheating brakes fumes made him goofy. :shock:

jb

[mitchntx]

Wow ... incredible pictures!

Robert ... a lottery ticket is in order ... I think.

Was the guy incredibly lucky due the rescue workers being Johnny on the spot or was he incredibly UNlucky for nailing a tree at exactly the wrong place and at the wrong speed?

Speculation is rampant and the bottom line is each of has to make a decision, based upon our own personal convictions. There is no right or wrong answer.

This was near tragic and we can all go beef up our cages to keep that kind of thing from happening again.

And then when someone runs off course and a limb goes straight through the windshield like a spear, we can all weld expanded metal across all the windows.

I'm not discounting the need. Don't get me wrong. If you need those support bars illustrated in Glenn's car, then by all means I think you should have them. When we are side by side going into T1 at TWS, I want your mental focus to be on driving, not worrying about what might align with the roof and cage and collapse it.

As general comment and aimed at anyone, what I DON'T want to see is a group of Monday morning quarterbacks saying "see I told ya so" or "I'm safer than you" statements. That's unproductive.

[AI#97]

http://www.lawmotorsports.net/Pics/Glenn/web/CMC70_build_03_700.jpg

This is on my to do list prior to hallet...was going to do it this weekend but have been sick as shit lately. After seeing the pictures....it may move back to the top of the list!

[Alien]

Since we're on cage safrty, I tend to take a lot of looks at rally car cages. These things are made with hitting trees in mind. All (WRC anyways) have the bar that Glenn points out but usually terminates at the mounting point. Another bar alot have is a stump bar, very low along the bottom of the door. Called a stump bar for the obvious. They also serve a purpose in a T-bone situation from another car. With a level hit, the NASCAR bars work well... unless the other guy is hard on the brakes in which case his/her nose is under the NASCAR bars.

This more than motivate me to finish off my original plan of completing my "X" door bar and adding another A-pillar bar, dashboard be damned.

[mitchntx]

GAry, we built Nick's cage with that "stump" bar in it.

http://www.lawmotorsports.net/Pics/Nick/web/Nick_Build_06.jpg

It also has a very high upper NASCAR bar and the cripple support everyone has been discussing.

Nick's cage will be a show piece.

[AllZWay]

Robert ... a lottery ticket is in order ... I think.

Was the guy incredibly lucky due the rescue workers being Johnny on the spot or was he incredibly UNlucky for nailing a tree at exactly the wrong place and at the wrong speed?

Speculation is rampant and the bottom line is each of has to make a decision, based upon our own personal convictions. There is no right or wrong answer.

This was near tragic and we can all go beef up our cages to keep that kind of thing from happening again.

And then when someone runs off course and a limb goes straight through the windshield like a spear, we can all weld expanded metal across all the windows.



Mitch is right on... You can never protect against every scenario that is possible in racing. Each person has to choose their own comfort level and no one is completely right or completely wrong in their decision.

[David Love AI27]

It is nearly impossible to factor in all the possibilities involved in a crash... for example what if there was a barrier to prevent the car from getting into the trees??? At a SCCA event at Cabiness (an airport for those not familiar) the track was deemed very safe because it was wide open with very few obstructions, however, a car had a stuck throttle, went flying across the course and hit a tractor, killing the driver... how do you account for that??? In this case, how do you factor in "passing out behind the wheel"???

How about the exhaust that went through the windshield at NPR? If it would have hit directly in front of the driver would the plastic visor save a life?

Don't get me wrong I'm all for safety in fact I'm willing to bet the cage in my car is the safest in the field including having my seat mounted on a framework of tubing welded directly to the cage... When is it overkill??? How many of you have the base of your seat support tied DIRECTLY to your cage??

We are so obsessed with safety on the track and yet we send our wives and kids out on the highways with overweight 18 wheelers out of Mexico that have bald tires and defective brakes...

On a lighter note if everyone drove a an overweight pig like the 27 car and kept your speed down (like I do) things might be a little safer :twisted:

[dirwin]

A little bit of triangulation and that cage wouldn't have failed. The obvious idea is to spread the loads over the greatest surface area, bars, gussets, floor plates etc... If you look at the triangulation and load spreads of the rear sections of the Audi cage, it held perfectly, and the seat didn't move. The front failed more than anything because of the long unsupported/untriangulated span.

The one thing that I really wish NASA would change is the number of floor mounting points. Like in Glenn's picture, spreading the down force loads over 2 bars is much better than one, taking that load all the way through 2 bars and into a floor plate tied into the rocker panel and your even better. So much of NASA/SCCA cage rules seem to be geared to limit any "competitive advantage" gained by making the structure more riged. The result is that some of the cage designs out there, while perfectly legal, are not safe, and some of the safest cage designs are not legal. With all of the dirt cars I have built in the past, I always take the forward upper support to the vertical door bar support, then all the way to the frame, IMSA doesn't disagree and I have seen some of my cars take side hits that would cave in a lot of the cars I have raced with in NASA/SCCA.

If you are using a unibody and the factory floor structure/rocker panels and trans tunnel are sound and the cage mounting points are located in the hard points of the unibody structure, there is really no need to tie the bottom seat mounts into the cage. If you are using a body on frame car and the cage ties to the frame and not the body (as it should), you MUST mount the seat to the cage/frame stucture, never ever ever ever ever do you mount a cage to a frame and the seat to the body on a body on frame car. Think about it, the body will move in an impact seperate of the frame/cage structure, your seat bottom and lap/crotch belts are moving with the body, the seat back and shoulder belts will be moving with the frame/cage. One direction of impact, your belts will get slack, the other direction and your belts will kill you. Neither is good.

The real moral to the story, if you don't know the engineering behind what goes into cage design, have someone who does build your car. After all, this is a hobby.


http://i195.photobucket.com/albums/z208/dirwin_photos/CMC70_build_03_700.jpg

[GlennCMC70]

Dave - Lou was politicing a rules change w/ NASA while i was building that cage. i did things as if it was gonna happen. the plan was to do as you pointed out w/ the two triangulated bars and w/ the side bars on the driver side door bars. we also almost made "floating plates" on the driver side for the door bar spacer tubes. we were going to keep going w/ the vertical bars in the door bars all the way to the rocker w/ floor plates on the ends of them resting on the rocker. the plates wouldnt be welded, just setting on top so as to not count as a mounting point. even that was getting alot of negative looks and feedback.

i think attaching the cage to select places like the windshild A pillar and main hoop to the B pillar are two places NASA is limiting cage safety. tying the cage to the chassis in as many places as possible is always cheap and safe.

[GlennCMC70]

keep in mind too, that the above cage was my first cage. Mitch and myself have changed things some since then and learned alot.

[mitchntx]

Like in Glenn's picture, spreading the down force loads over 2 bars is much better than one, taking that load all the way through 2 bars and into a floor plate tied into the rocker panel and your even better.

http://i195.photobucket.com/albums/z208/dirwin_photos/CMC70_build_03_700.jpg

Dave, if you look at the 5th cage we built,

http://www.lawmotorsports.net/Pics/Nick/web/Nick_Build_06.jpg

We took advantage of what you are describing.

And while we were unable to attach a bar to the floor, we installed that 3rd bar down by the sill, just a couple inches off the floor. So after some deflection, the bar hits the floor and spreads the load just like an additional mounting point.

[GlennCMC70]

Dave - this is how we do them now.
http://www.lawmotorsports.net/Pics/Nick/web/Nick_Build_03.jpg

[dirwin]

Mitch & Glenn,

The red car's cage is outstanding. Load distribution is a product of a properly engineered cage. If a new builder doesn't understand the force dynamics involved in a crash and are not able to engineer the cage properly, DON'T build it yourself.

With our Mustangs, they are plated to the upper A pillar as well as both the upper and lower B pillar. We are able to get these through because they are Grand Am legal and were built by Multimatic.

It has always been my experience that if you bring up or propose an enhancment to safety and structural integrity to the scrutineers of both SCCA & NASA they will usually be pretty receptive. They will look and see if it is a performance advantage you are going for or if it is truly a safety issue.

[dirwin]

Just another note. To tie the cage into the A & B pillar's is of no value if the pillars have been gutted for weight reduction as is very common with AI and A-Sedan. The only reason it works on the Grand Am car is the roof and pillars have been untouched and are still as delivered from the factory.
http://i195.photobucket.com/albums/z208/dirwin_photos/MVC-011S.jpg
Again, I really like your red car, the workmanship and engineering look like they have been well done.

[mitchntx]

Again, I really like your red car, the workmanship and engineering look like they have been well done.

I appreciate those words. It takes time to build a "reputation" and it appears LAW Motorsports is headed in the right direction.

It takes a LOT of time to buld a cage like that and close to a grand in nothing but materials. If I recall, there is 120' of tubing in Nick's cage. Last time we checked, DOM tubing was over $6 a foot!

[dirwin]

Building a good cage takes a lot of money, time and knowledge. I have told people for years if you are going to cut cost, don't do it in the cage, seat, seat mount and fire suppression. If you have to cut these areas in order to race, go to another class or postpone racing. Too much is at stake and none of us are going to make a living driving these things anytime soon.

The cars I have built over the years have been built as if I were going to drive it and you guys do it the same way. As expensive as it is, and as much thought and time goes into building a race car from scratch I know you and Glenn aren't doing it to get rich.

You hope you never see it, but pride comes when you see one of your cars on it's top and you know the driver is okay. The driver/buyer then realizes, while expensive, it was worth every penny.

[mitchntx]

When James tried to create a new Pit In at MSR-H, once we discovered he was OK, the first thing I did was see how the cage held up.

It's a fine line between being morbid and looking for opportunities to improve when it comes to looking over a cage after it's been "tested".

When Jerry was rebuilding the Micah rollover Mustang, I asked for detailed pics of the car and cage. Jerry quickly obliged and I hope he knew why I asked for them.

When the 2 911s got together at MSR-C, one T-Boning the other at corner exit of Big Bend, I wanted to look the cages over really close to see what bent and where.

Glenn brought up a good point today. There is a cross bar shoulder high to send some loading to other bars. Maybe a bar 6" off the mounting plates which would put it about hip high all to help shore up a nasty side impact.

I like the way Daron and Mason's door bar setup. And I like what a lot of dirt sanctioning bodies are doing ... installing a metal plate in the door bars.

I like the way we move the main hoop diagonal from intersecting at the point where the down tube meets the main hoop to 12" inside that point. It creates a cocoon for the driver's head, with a support bar on either side.

Thank goodness 99% of us will never use our roll cage.