Collision safety in our cars

[oprn]

This subject keeps coming up in discussions particularly around our glass bodied street buggies but does apply to other types as well.

Virtually none of our cars were ever designed with collisions in mind and we strive to drive in a way that it does not happen. At least I do. I know I am very vulnerable out there, very little better than riding a motorcycle so I take the biker attitude that everyone out there on the road wants to kill me! It's worked so far...

The "safety fix" that is always without exception suggested for our cars is to build a roll cage. Now before we go any further, I want to say that I am not here to bash roll cages, they are very useful things in a roll over. Absolutely essential for us in our open Buggies in serious off road driving. I am not talking about the traditional "rat trap" roll bar, the jury is still out on whether or not they are better than nothing! However... statistically... on the road only 3% of collisions actually result in roll overs! The other 97% are frontal, side and rear collisions.

Let's think about that. We do not have crush zones, impact side bars, energy absorbing bumpers or air bags. Some of us have collapsible steering columns... sort of... but yet we advocate only for protection for the 3% out of all the serious incidents that could happen. By only focusing on roll cages are we luring ourselves into a false sense of security?

The vast majority of roll cages out there are, by design, very weak from the front or rear and especially the side. Now there are a few roll cage designs I have seen pictures of that have bars angled enough to the rear and one or two designs that have bars that go past the windshield that would provide some limited value/protection in front and rear collisions it is true. What about side impacts? When I am out in the traffic in our Buggy, I feel extremely vulnerable from the side. In fact a knuckle dragging Neanderthal degree of vulnerability! Can we effectively do something about that? I think it is possible. What about better front and rear protection too? Can it be done without the car being dominated by the safety features? Turning it into an ugly rolling pipe rack? Thereby lies the challenge in my view (pun intended!). Any solution is going to be a compromise I am sure.

Thoughts and ideas on this subject please.

[Ol'fogasaurus]

Safety is not always pretty!

On my black buggy I am still fighting with the cage and what/how it supports what the pan can't.

DSC00647 (2) copy.jpg

This is more or less the start of the VW pan. The front-end beam mount is in place as it is spot welded to the underside part of the front of the pan. Changing the head from BJ to K&L requires one to get the spot welds removed from the pan's beam mount and replace it with the other style of mount that you want to use.

The welds on the rest of the pan assy are spot welded so a good smooth reweld should be done. Remember that in the tunnel there are "things" that usually need to stay so don't weld permanently close out the access door in the front end.

After market floor pans are available in a couple of different material grades/thicknesses.

The body mounting flanges on the sides give some strength but not that much as the material used is thin and the flanges are not really designed not to work without the body attached. The floor pans do not aid much in torsional/twisting, that has to be taken care of other ways. The main body with a top on the unit is a stronger aid as it has the top to spread loads fore, aft, side to side and crossways more that the bare pan does.

To change the rear to IRS from the earlier suspension requires aftermarket pivots for the IRS suspension arms to be added.

If you are going to a bus trans, then its shifter nose sits higher to the top of the buggy's tunnel not through it like the stock unit does. Work will have to be done there.

Also the rear shock towers need to be supported to keep the shock eyes from breaking off.

The pan area from the rear mount (ahead of the engine area) to the "Napoleon's Hat" area is where the cage will sit. Depending on the body design you have to deal with that but one thing I would add is that on the top of the cage an "X" setup should be added to deal with torsional spread.

cagesamplesW[1].jpg

There are a lot of cage designs out there. I'm not sure if any of these are street good or not as the states may of may not approve of the design.

Anyway, this is probably a very incomplete start, and I am sure there are other opinions on this. I am still futzing about the cage design and other supports for the pan like the front "wings" and the running boards.

Lee

[oprn]

We can beef up the roof all we want but the fact remains that there is only a 3% chance we will need it on the street. A side collision is the weak underbelly of all automotive designs especially our kit cars and is far more likely to be involved. That is the area that concerns me. We will never really eradicate that soft point unless we do an extensive sand rail like structure around our glass car bodies. At some point the car becomes something we no longer want to drive due to access and appearance issues. At that time it's best all around to drive something properly engineered with side pillars, impact rails and air bags.

However I see no reason we could not improve on our present kit cars to some degree without getting lost in a bubble wrap exercise and creating an eyesore. Some sort of a compromise between vulnerability, and authenticy whereby we still want to and it is reasonably safe to enjoy our hobby. I suppose that target looks a bit different for each individual.

[Ol'fogasaurus]

Back in the 60's a friend of mine who ran (who later owned it and the other 3 shops) an exhaust shop had built a buggy for a neighborhood kid. It was a stock length, swing axle bug pan and, as usual, he did a good job. The "thing" back then was a "hoop" instead of a "cage" which he made.

Another thing back then was "Rat Racing" of which a similar thing is now in vogue with the teenagers. He was in "Snoose Junction" (a slang term for an older area of the large town we were in) which still had cement streets. Anyway, he was "Rat Racing" around when the cops caught sight of him so he tried to outrun them. On one corner, his swing axle rear wheel got caught a seam (gap) between the two pieces of street causing the wheel to "hook" and he went over. The "hoop" on the buggy laid down (as they usually did) and he was killed. The builder was devastated!

Anything that can and usually will happen so one should build for it.

Fiberglass itself is not really that strong unless it is a "foot thick" and then that is "Humm".

Like you said, side hits or being run off the road by someone not paying attention needs to be thought out in advance. If you sell it to someone and they get hurt or killed, are you going to feel bad if it was caused by something you did or didn't do?

Lee

[Ol'fogasaurus]

If you look up the term "Rat Racing" it is an older term than I thought. Back when the scientists were running mice through mazes to see memory and other things mice (and people) hand. That is where the term I used it as. "Digging Donuts" is also back in use where people are spinning the cars in an oval cooking the tires. Also was (less) done when I was a kid. It seems like things reoccur in about 20 year cycles but that is a guess as it may be quicker .

Lee

[oprn]

We all did dumb things when the testosterone was high and the brain cells were still 1 /2 empty...

I am thinking now about a side guard made in a "Z" shape, the bottom against the pan and the upper tied into the shock tower at the rear and a dash hoop at the front. It could be painted to match the outside color of the tub (black in our case) or covered with side pods if you have them. This would add a bit of torsional rigidity to the body too.

[Ol'fogasaurus]

We all did dumb things when the testosterone was high and the brain cells were still 1 /2 empty...

I am thinking now about a side guard made in a "Z" shape, the bottom against the pan and the upper tied into the shock tower at the rear and a dash hoop at the front. It could be painted to match the outside color of the tub (black in our case) or covered with side pods if you have them. This would add a bit of torsional rigidity to the body too.

Z shapes can deform (in this case, assuming I am understanding what you are saying) depending on the load direction and other things.

Are you are going to weld the three pieces together? The over 90-degree angle might be subject to collapse, but again I would have to see just what you are talking about. Formed "Z" material will have a radius of more the 90-degrees (depending on the size of the bent flanges and body) so the radiuses might be not as strong as 90-degree bend.

The "hoop" you are talking about I am not sure what and exactly where you are planning to use it.

To make sure I was going to give info on Torsional loading I looked it up and I had forgotten just how much the term "Torsional"[/b] covers . I also looked up Z shaped material and got this: https://www.metrosteel.com.au/everythin ... e-besides/. I didn't remember this shape being referred to as "Z" shaped material. Either of these shapes I don't remember of being used or I/we designed their use. Each of the flanges point in different directions so a lot of strength is probably lost in certain load situations. Something interesting for me to think about as I have been retired for so long.

If, in this case, you are talking about the twisting of the pan because the original body in now gone, and a glass body is being used then you need to go diagonally across from corner to corner. If you are talking about "side hits" then other things may come into play. For what it is worth: https://www.bing.com/search?q=the+load+ ... 91&pc=LCTS

I know it is complicated but then complication is something mother nature throws at us all the time.

I am enjoying this discussion as it is interesting and giving me things to think about that I haven't used for over 23+ years. Thanks again and don't think this is a negative conversation, it has good things to think about.

Lee

[oprn]

No I am not talking about the shape of the material used. I am talking about the shape of the structural member. The material used could be pipe or square tubing. Also the dash hoop is the bit under the dash that the steering column is fastened to. Maybe this goofy sketch will clear to up

[Ol'fogasaurus]

No I am not talking about the shape of the material used. I am talking about the shape of the structural member. The material used could be pipe or square tubing. Also the dash hoop is the bit under the dash that the steering column is fastened to. Maybe this goofy sketch will clear to up

The drawing sketch is a good idea aiding the dialogue. I am having a big bunch of plus and minus arguments with myself over this as I had to figure out what your idea really was as my first look was different than what I think I am seeing now. Again, good job!

If you have a hoop in the front by the firewall that would be in use... then maybe... but the bottom of the hoop would need a stronger support (I would think) on the floor area but then you have the tunnel and pedal assemblies plus your tootsies to deal with. Maybe higher than the tunnel might work but the material and other things can come into play also.

7-28-2010 007 (2).JPG

This is the body lift I did for my black buggy. I know it is not what you want to do but I am posting this so you can see (what I think) the idea is you would have to connect the parts of your sketch to somehow... to something stronger than the flanges of the pan halves plus having to deal with the cross-structure for both mounting and side hits. When I talked to some of the engineers I worked with, they were somewhat confused also (not car people and busy on other things) but they did see some of the good parts in it. Remember, the pan floors are not that thick of material to start with.

If you have a hoop in the rear that this structure was attached to then... no. The top of the hoop would need support also as the unsupported part could/would fold back on a roll or a flip.

The upper side mount and the diagonal side support mount still would need more support in case of a side hit and the mounting of the. A body mount would not be strong enough for anything more than a fairly light side hit but that also is something you cannot control either. I think a couple of verticals supporting the diagonal might be a good idea also.

My black buggy body would not work due to it's shape/design.

The diagonal angle would be good for a head on or side hit but not sure about a rear end hit. I do like the idea though.

I'm still arguing with myself on some things, so I'll try to give pluses and minuses as this goes on. Again, I haven't had the opportunity to go over new design ideas since the late 1900's. I'm still arguing with myself over some things on my black buggy even now.

Lee

[Ol'fogasaurus]

Had dinner and talked to the wife about it. She did not understand a bit but it gave me a chance to think without having to correct my spelling all the time

If you look at the 1 1/2 X 3 rectangular tubing notice the rectangular flat plates on the inside of the tube. The bends in the pan and the body lift are where the front and the rear of the doors are. I bent the tube by "Kerfing/pie cutting" the tube. I bent them, clamped them in place then welded the cuts then added the doublers over the seams after finishing the welds flat then added the doublers by slightly over bending the doublers, then clamping the doublers in place, spot welding the center in place then clamping the ends against the tube then welding them the finished the welding of the doublers over the seams. Your tubes would have to be bent also so that comes into play. The diagonal would be a doozy to do but I still think I like it.

Kerfing is more of a wood working term, but I had heard it used in metal work also. "Pie Cutting" might be more common of a term but they still do the same thing.

All three of your pieces of stock will have to be bent also. Mostly for the front to rear of the pan but the bigger bend would be for the passenger seat as that is who you are trying to protect besides adding strength to the pan.

We have only one rail left in our group right now and I think it might only have the one bend on the floor tube and the upper side tube. It might be two but I haven't had to play with it for a while.

Unless you have someone, who is good at bending the real stuff, I would think that for the diagonal tube getting some lightweight (more inexpensive) stock to do the mockup piece with. I don't think that wood would do the job as well but then again, who knows!

The upper and diagonal tube dia. should probably be the stock cage 1 1/2" dia. but I am not sure what the wall dia. is. Again, no welded seam tube as the strength is not there.

Lee

[Ol'fogasaurus]

The one point in the diagonal would be ones legs in a side hit. If the pan is stock length and the seat is back to the rear bend one's legs could be low but if the pan is shortened then the lower placement of the diagonal could put one's legs in not of as good of a situation.

Again, the foot pedals have to be delt with also.

Lee

[oprn]

Yes as you pointed out it is not a perfect solution but I am not looking for perfection, just an improvement. We cannot make ours cars completely bullet proof in a collision but I do believe advances in safety can be made. I do have a cheap hydraulic pipe bender so following the curve on the side of the Buggy is not an issue. I changed my sand rail from a short back to a long back including an engine cage with it several years ago.

On the diagonal braces it is a shortened pan Buggy but one could use two diagonal braces to get a steeper angle. That would do two things, a shorter span is always stronger and two braces would give better coverage than one.

As for the lack of horizontal support by the driver's feet, perhaps there would be room to add something forward of the firewall under the tank and just over the tunnel.

[oprn]

Also I might add that there is a danger of building a structure that it too ridged, too strong. The force of the collision is then transferred to the occupant and it becomes a case of the collision within the car, human body vs car body. That is why we have crush zones, to absorb the energy of the impact with the car body instead of transferring it to the human body. I don't know how many people understand that. A stronger structure only protects you up to a certain point, then it starts to become a detriment to survival.

That applies more to front and rear collisions as there is no room for a crush zone on the side of any car unfortunately.

[Ol'fogasaurus]

Will a strong build throw someone around... yes, but so will a weaker build and there may be more damage.

[Ol'fogasaurus]

Will too strong build throw someone around... possibly but that would need to be accounted for in the design, but... so would a weaker build and there is going to be more damage done in either way. Remember, the fiberglass body is not what one would call really structural.

If you draw a straight line from the rear corner to the front corner (see the previous picture). If it were a 1 1/2 dia. tube, say for part of the cage, it probably would hit/touch the seat depending on the seat size and location but even if it did miss it, it would be too close to the person for safety. It also would put your legs very close to the tube where a side hit would/could be.

A cage's rear hoop should be at least 4" above the tallest person in the vehicle and a helmet would add to that. One of the guys I knew flipped his rail and ended up breaking his neck (yes, on the sand but getting thrown about in something like that even on the street could/would happen on the street too. He lived for 8 more years in a wheelchair not able to move while his wife was the main support for all his needs to help him.

The cage should have a lower bar setup just off the floor and another below one's elbow. There should be vertical/angle tubular joins between the two bars. The diagonal design looks cool but not going to be a good working element.

The harness has to be mounted to the floor and the top of the harness is to be lower than where the harness strap goes through the back of the chair. This is to hold the person down in case of a violent situation.

Again, load transfer normally would be through the Bug body but without that the cage (if done right) should handle some of it.

leebuggy-12%20copy[1].jpg

leebuggy-1%20copy[1].jpg

Lee