Roll Cage Failures

['84 Bronco II]

The "Minimalist Cage Designs" thread inspired me to create this thread. There were a few good cage failure threads on pirate and I always though they were quite interesting/eye opening. I am hoping this can become a sticky thread since this is an important topic and I think there is quite a lot to be learned from failures and actual data points.

Fortunately, I don't have anything to personally contribute, but I hope others can. This is not intended to be a "what do you think of my cage design?" or "If you build your cage out of poop pipe you're going to die!!!" thread.

I am hoping people can post pictures of their cages after significant rollovers, whether or not they held up, and provide details of the rollover and design of the cage (diameter, wall thickness, material, etc.). Then we can all speculate on why the cage held up[ or not, and use these data points to improve future designs or establish what is "good enough".

 

[JR4X]

2 min 45 seconds into this video. We're racing and get cut off by one competitor who checks up and allows a much slower rig to get in front of us. If you watch the first two minutes you can see us trying to get around a car that's swerving around wildly, so while we need to get past him we're trying not to get taken out by him at the same time. At 2:42 I tell dad "we got him" and dad hammers down. I saw the speedometer at 70 mph when we hit the jump, but we land on the slower car. Our right rear comes down on his left rear and I think we were going about 20 mph faster than him. It pitched us straight to the A pillar and caused us to violently endo pirouette to a barrel roll. The sudden stop was hard enough to knock my dad (driver) out in a vehicle that with our HANS devices our helmets CANNOT touch anything. If you watch the video in segments you can see we roll over off the other cars tire, straight to our driver A pillar. When the A pillar digs in thats what pile drives the nose into the dirt. The main cage didn't bend at all, it just smooshed the nose in. We cut the front hoop off and raced in the main earning a 3rd place podium spot after starting dead last.

https://www.facebook.com/KingofTheHa...zMzEzNzQ4MDY5/

Photobucket is a piece of shit so no matter what I do I can't change the order of these pictures. The bottom pic is me driving it back to the pits from the crash spot showing pre repair.







and here are a couple bare chassis pics from when it was new

 

['84 Bronco II]

Reserving this post for content. I have pics and vid of a cage that held up to a 69 mph direct landing on the drivers side A-pillar. Still have the chassis. I have pics of another one that we can debate wether it was a failure or not. It saved my life but it was done after that. Wouldn’t have saved me a second time over. It’s Saturday and I’m at work. I’ll come back and edit this with mucho pics and vids.

Awesome, great way to get the thread started

 

[ArTi54N]

I used to sorta know someone with a jet engine in his truck.. saw him the wall at somewhere over 200mph.. he walked away.. kinda wonder how much they spent on the cage.. and if a cage that good would be overkill for 4x4s

also, right before I totaled my 4x4.. I was gettin prices for cages.. speakin of a wide range of prices..

 

[SLOWPOKE693]

I went a bit overkill with the cage on my short course SxS just in case bad shit ever happens. Hopefully I won't be posting "after" pictures anytime soon.

 

[Wulf]

Not mine but I saw this brand new SXS on the trail right after it happened.

 

[92 Green YJ]

Looks like some shit welds on that side by side. Particularly that door bar. No penetration at all.

 

[SLOWPOKE693]

Looks like some shit welds on that side by side. Particularly that door bar. No penetration at all.

Every single one of those stock cages, no matter what the brand, is a death trap. Welds suck and the tubing is like .045 wall. I swear your probably better off pulling the factory cage and ducking in a rollover. At least then you don't have to worry about the "cage" coming down on you.

Honestly, I can't believe there hasn't been tons of lawsuits over that yet.

 

[SLOWPOKE693]

Here is one I saw last year that got T-boned. Not good.....

 

['84 Bronco II]

The interesting thing to point out about the Maverick cage is that besides the crappy weld failure, all of the apparent tube failures are where reinforcements were added and created stress risers. The swept back A-pillar is obviously done primarily for styling and left it very week. Can-Am is obviously aware that is is a poor design since they added the big gusset at the primary bend to reinforce the A-pillar, but this reinforcement may have been more of a detriment seeing as it caused the tube to kink/buckle rather than just bend to give a little. Had it had a secondary A-pillar like this buggy to create some triangulation and support that sweeping roofline, things probably would have went better

All that said, it does look like the cage did adequately protect the driver, so it did serve its purpose. It just could have been designed/built better so that it could have been used more than once.

 

[SLOWPOKE693]

Reserving this post for content. I have pics and vid of a cage that held up to a 69 mph direct landing on the drivers side A-pillar. Still have the chassis. I have pics of another one that we can debate wether it was a failure or not. It saved my life but it was done after that. Wouldn’t have saved me a second time over. It’s Saturday and I’m at work. I’ll come back and edit this with mucho pics and vids.

And then......

 

[YotaAtieToo]

I have the same rig as above, I thought honda did OK using 2" and a little be design than some of the others. I guess I didn't think they would be dumb enough to use stupidly thin tubing.


You guys need your eyes checked. The weld did not fail, the tubing ripped open. Again, a result of way to thin of material.

 

['84 Bronco II]

Alright guys, let's try to get a little tech in here instead of just making this a dump for pictures you found on the internet. Please try to post some basic information with the pictures such as tubing size and material grade as well as what were the conditions of the roll over were, i.e. speed, number of rolls, etc.

Also, I would prefer to discuss actual rigs instead of factory cages on golf carts Perhaps if it is a custom cage it would be worth posting up. The intention of this thread is for people to learn and see first hand the performance of various roll cage designs so that they may be able to determine what is "good enough" for their particular build or to avoid making critical design mistakes.

 

[JR4X]

And then......

I'm trying The video I need to attach is the Ultra4 Stampede - Rancho Cordova Cali 2017. If P4x4 worked right I could find the video, I can't find it anywhere now. Gonna be hard to adequately describe the context without the video. Need more time to dig.

 

[mobil1syn]

not sure id call mine a failure, it did what it was supposed to do and kept the occupants alive. a few small changes and chances are i would have revived the truck. door bars and sub belts. all tube was 1-3/4x.120

my build thread - http://www.pirate4x4.com/forum/toyot...ck-thread.html

thing to remeber is to keep the seats attached to the cage. this way in the even the body separates from the chassis you are in the cage. think of it the way an f1 car explodes.

mine did its job, kept me and my wife (gf at the time) alive. we both ended up with staples in the dome, could have been avoided if the sub belts where installed. see the thread for the discussion regarding this. no one saw me roll since my buddy was on his bike. given the way i ended up and damage on the vehicle im fairly certain i was airborn at one point. cage stayed centered in the cab,

the front end and the cab stayed put fairly well. door bars would have kept it solid, didnt have em though you could see where the dash bar bent as the the front corner tried pushing itself through the cab. the back of the truck too a big hit and bent bad just past the shock mounts. understandable since there was no lateral support past that point. back half and links would have been the ideal solution. decided to get married instead of rebuilding.

in the far away shot you can see where i made contact with the bank and where the truck ended up.

 

[JR4X]

And then......

I'm not happy about how this is going photobucket and PBB ruined everything. Some pics posted. Wishing I hadn't decided to play but I'm still working on it.

 

[gt1guy]

I'm not happy about how this is going photobucket and PBB ruined everything. Some pics posted. Wishing I hadn't decided to play but I'm still working on it.

Don't sweat it. You got the vid and pics up.

That looked like a healthy roll. Surprised the A-pillar didn't move, so it seems running that vertical A-pillar brace did it's job.

 

[thedirtman]

Did a full frontal roll off of Death Hill at Prison Hill ORV. Main hoops 2"x.120 wall DOM. Hit hard on the driver side windshield and the A to B bar. Only damage to the cage was the bend in that bar. It was a pretty good drop maybe 8-10'

 

[MochaMike]

I think some of you are taking "roll cage failure" the wrong way.

The purpose of a roll cage is to protect the occupant(s) as much as possible. Not to keep the vehicle free of damage/keep it unscathed.
Granted, many of them protect the vehicle enough to keep on trucking.
But given the right circumstances, anything can be destroyed and people can be injured/killed (Dale Earnhardt comes to mind).

That being said, here are my pics: I rolled off a ledge at the top of the slabs on the Rubicon (there are steps on the left looking up with a small tree on top, or you can take a big ledge to the right of a large tree to the right. I went up to the left & as my LF tire climed a boulder, my RR dropped in a hole/slid of the ledge which made me roll toward the PS.
I thought it would just be a flop but gravity prevailed and then I slid of the ledge landing on my lid, then rolled 1/2 onto my DS. When I slid off the ledge landed on a cooler size boulder centered almost exaclty between the DS & PS seat above my head. The cage held, but did collapse in the center about 12-18".

A little about my cage design (which has since been added to). The A & C pillars are a single tube, So it goes from base of A, straight back over B, and then at an angle to C.
The C is a stringer, with stringers connecting the As below the steering wheel and above, Bs had a stringer as well. I ran base stringers from A to B, with 2 more connecting DS to PS which my seats are mounted on (most of this was to help with frame flex, since I'm bolted to my sliders and frame).
Originall there were 2 stringers in the connecting the A to A & B to B stringers (center of rig, above my head), I had added sheetmetal strip between them for stereo & CB.
I eventually added a U shaped halo connected to the top of Bs to protect the kiddos in the back.

The design left a 2'x3' open squares above the driver & passenger seat.
I'm pretty sure that if that boulder was another foot over, I probably would have suffered a head injury. That really freaked me out.
So, I changed the design adding more triangles (probably overkill).

You can see the rectangles over my head in the moon rocks picture.
Note the rock in the shadow.

 

[MochaMike]

Carnage

 

[MochaMike]

Fix/Version #2:

EDIT: Currently there is some plate coming up the center behind the rear of the seats where my shoulder harnesses attach to. Plan is either this month or in the fall to run another stringer between the B pillars to attach the harnesses. However, my seats lean back behind the B pillars, so I'm not sure if I can get a single bar with bends behind them, or if I have to run a straight bar further back, with simple 90* joints. If I do that, I'll probably run 1" or 1.5" instead of the 1.75" I have for the rest of the tube.

 

[JR4X]

I think some of you are taking "roll cage failure" the wrong way.

The purpose of a roll cage is to protect the occupant(s) as much as possible. Not to keep the vehicle free of damage/keep it unscathed.
Granted, many of them protect the vehicle enough to keep on trucking.
But given the right circumstances, anything can be destroyed and people can be injured/killed (Dale Earnhardt comes to mind).

That's what I was trying to get at in my now edited post. When we started racing we didn't anticipate the speeds we would be going now. Our car in post 2 was built with the idea of not only keeping us alive in a rollover, but to be repairable quickly between races. It was rolled at race speed over a dozen times and while it's retired now if I had to pick something to wreck at 70 it's still my number 1 draft pick. It's also heavy which became an issue for being competitive. Our new car that replaced it weighs over a thousand pounds less, but we know that the cage will need replaced after it saves our lives. I'm putting together my next set of pics which show a cage that saved my life in the scariest situation I've been in, the cage held 5000 pounds off me and my passenger but it deformed and broke down rendering it unusable for further competition.

 

[Stephen Wilson]

Fix/Version #2:

EDIT: Currently there is some plate coming up the center behind the rear of the seats where my shoulder harnesses attach to. Plan is either this month or in the fall to run another stringer between the B pillars to attach the harnesses. However, my seats lean back behind the B pillars, so I'm not sure if I can get a single bar with bends behind them, or if I have to run a straight bar further back, with simple 90* joints. If I do that, I'll probably run 1" or 1.5" instead of the 1.75" I have for the rest of the tube.

I understand you have rear seat access to deal with, but the only lateral triagulation in that cage is the small windshield "A". It really needs more, especially at the B pillar.

 

[SLOWPOKE693]

I understand you have rear seat access to deal with, but the only lateral triagulation in that cage is the small windshield "A". It really needs more, especially at the B pillar.

Agreed

 

[gt1guy]

Roll cages really need to be looked at like a consumable. A cage that gives a little bit in a crash is actually absorbing impact energy that would otherwise be transferred to the occupants. That's a good thing to have happen....as long as the occupants are still within the protected bubble (for lack of a better term) of the structure. It's when you start having B-pillars give way that you're in trouble.

 

[JR4X]

Trying the posting here thing cuz f@ck photobucket. This thing was built to be a pro mod comp crawler and won the national points for W.E.rock in 2010. Samurai with an Exo cage with lots of cross bracing going through the body, Huge X in the double B pillar behind the cab wall. In 2011 it was converted to be an Ultra4 car when there was no classes yet. It had a fire in 2011 KOH and DNF'd, in 2012 we ran it in the first ever EMC. My only fear going into desert racing was doing a cart wheel yard sale. I'd only been in the truck 10 minutes shock tuning with King when we did a full on yard sale endo at 60. The cage held it off our heads with no real damage to the cage itself. After many other flops and rolls doing minor damage at most. In 2017 I was racing a Bonneville Offroad Race in Utah. Part of the course was ran on a dirtbike track, We pran ran it and I decided there was no safe way to do the jumps so I was just going to roll over everything. First lap of the actual race I thought I was hitting a table top so I hit it with enough oomph to fly thinking I'd land on top, slow down and roll the rest of it. Hit it way to hot and cleared the whole thing landing full lawn dart 20 ft past the end of the catch ramp. It landed on the nose all metal to ground no tire or suspension absorbing the impact. It shit whipped us onto the roof, over onto the tailgate and back onto its wheels. When it landed on the wheels I hit the start button and it started. I went to ask my co-driver if he was good to keep going. That's when I noticed I had a physical problem. The impact knocked the wind out of and I couldn't breathe or talk. I shut the rig off and climbed out unable to breathe for what seemed like an eternity. All the responders and my co driver are shaking me trying to force me to answer questions and I just couldn't. Once I could finally breathe we used the winch line to hold the hood shut because the hood latches had evaporated. We ran and got second in 4500 and beat most the 4800's racing with us. After getting it home and surveying the damage I realized I probably should not have continued. It had a lot of failed tube in the HAZ areas next to the welds, and a lot of deforming. With all the previous rolls and this one literally saving our lives I don't consider it a fail. But that was the end of that chassis' life. I cut it down and kept cutting trying to get down to something straight and there was no saving it. I ended up stripping it down and hauling the chassis to scrap. I'm a fan of the double B pillar for strength, and lots of triangulation really does work.

 

[MochaMike]

I understand you have rear seat access to deal with, but the only lateral triagulation in that cage is the small windshield "A". It really needs more, especially at the B pillar.

I've known that for a while, this cage is over 10 years old and isn't as good as a new one would be design wise.
Space is the major issue, a lot of guys put the B pillar further back, which isn't on the floor in the cab, but on the inside of the upper fender well (it turns the length of the bed,,,, see in earlier pics)
My having it on the floor, the seat has to extend past the B pillar.
In this pic, my seats are currently all the way forward (I moved them forward before the winter after a fall run 2 years ago to access stuff in the back, and the rails rusted. Normally they sit reclined more and the bases are further back.

So, I can't put anything diagonal between the B pillars.

 

['84 Bronco II]

Thanks for the latest contributions!

I don't want people to get caught up in the semantics of "failed," and in fact wish I could change the title of the thread to more accurately reflect what is meant to be posted. Basically any cage that got "tested" should be posted up regardless of whether it sustained damage or not. I am hoping we can build a good resource of real world results with good technical discussion, so people can more accurately determine what is good enough for their rig and the way they use it.

 

[SLOWPOKE693]

I've known that for a while, this cage is over 10 years old and isn't as good as a new one would be design wise.
Space is the major issue, a lot of guys put the B pillar further back, which isn't on the floor in the cab, but on the inside of the upper fender well (it turns the length of the bed,,,, see in earlier pics)
My having it on the floor, the seat has to extend past the B pillar.
In this pic, my seats are currently all the way forward (I moved them forward before the winter after a fall run 2 years ago to access stuff in the back, and the rails rusted. Normally they sit reclined more and the bases are further back.

So, I can't put anything diagonal between the B pillars.

With some slight bends you could. It wouldn't be ideal in terms of absolute strength but it would still be a big improvement IMO.

Question: What are your shoulder straps on the harness attached to now?

 

['84 Bronco II]

I figured I would post up a roll a buddy had in his BFR CK1 chassis buggy in Farmington a couple of months ago. The chassis is pretty much all 1.75" .120" wall DOM tubing, and his buggy weighs right around 3,800 Lbs.

I wasn't there to give a better description of what happened, but here's what he had to say about it when he texted me the pictures:

Little bit of damage but not too bad. Roof panel is caved in a bit on drivers side, and the passenger upper bar has a small dent. Nothing crazy though.
Forgot my light bar is trashed.
The trail I was on was called Coco. It was a sandy sending hill and I didn’t have much traction kind of shot me off the top to the right it was a pretty hard hit. My neck was hurting pretty bad yesterday afternoon.