Building a ROPS?!

[mark777]

For me, here it is in a nut-shell.

A certified ROP's rated for your make and model is "legally" better. Even the residual value of your tractor will be higher than that of one without the same structure. Most manufacturing companies meet all the minimum standards, but still keep costs down to maintain a higher profit margin.

And (as Eddie stated) a competent weldor with the correct materials can build one as good, or better. Diagonal supports, gussets and higher grade hardware is a good example to a superior hand built structure.

This is the catch and it's a real "Catch 22":

If you build and install a ROPs and seat belt for yourself that's OK....even legal. If you sell that tractor, or build a ROP's for any other tractor then you are liable for any injury sustained, regardless if it's the operators error or not.

If you build a ROP's but call it something else, like a HD canopy support and include seatbelts, your liable for the same circumstances as above.

And finally, doing the same as above and not including seat belts is as, or more dangerous than a tractor with no structure at all. I hope this helps in understanding why I do not manufacture my own (IMHO well built) ROP's.

Mark

 

[OldMcDonald]

What kind of seat belts do you have on your tractors, lap, diagonal as in cars, full harness? I have never heard of seat belts on ag tractors until this thread. Old McDonald.

 

[drmiller100]

u guys are funny.

a tractor flips, and what are the odds you will end up still sitting in the seat when it is all done???? so you all wear seat belts????

any rops is better then no rops at all.

Roll bars for race cars have some GOOD information. If you built a roll bar to specs for a 12 second quarter mile car, you'd probably be pretty safe in your 2 mph tipover. In particular, use good materials. Square tubing is a joke. If you are doing it yourself, either use a LOT of THICK steel, or mandrel bent roll bar tubing.
Further, use good mounting points. A roll bar that attaches in two places is worthless. Have a roll bar that attaches in at least 4 positions, each at least 3 feet apart. the earlier post is a great example. If that bar had just two forward supports, the kid might have lived.

The quarter mile fab shops are pretty friendly folks, and they have a LOT of experience, and they are usually REALLY friendly about helping people design good quality roll protection at very reasonable prices. And they have a LOT of experience in thinking about roll over protection.

Just my thoughts.

 

[markct]

drmiller100, i agree with you entirely that any rops is better than no rops. my dozer has a canopy type structure that i made primarily to be safe from falling tree limbs and such, while it dont consider it a rops by any means, if i ever were so unfourtanate to have a rollover its very likely that it would keep the machine from goin all the way over, it would probably stop it on its side, a much more likely place to be able to survive. another case in point is that i know of a guy that had a ford 8000 ag tractor, very simular to the one i have, it had a non rops cab on it, it was not a strong cab by anymeans, just formed sheetmetal mostly. he had a rollover, the tractor stopped on its side rather than going all the way over, probably saved his life, im not saying i would trust that type cab to be a rops by any means, but it was enough to stop it, thats better than nothing at all!!! my ford 8000 has the same style cab and i plan to build a rops for it eventualy, i have no worrys at all about building it. me and my father are the only ones who run it, and i am a competent welder so i see no reason not to build one. can hurt

 

[mark777]

Just a lap belt. The type you see on any late model tractor, with Torx bolts and welded nut plates for anchor points.

 

[kenmac]

Jerry , if you look at my 1st post on this thread I have a linc to the accident you refer to.

I talked to one of the yanmar dealers that had alot to do with getting ROPS developed for yanmars. He said that they don't roll a tractor to test the ROPS ,that they use hydraulics in the test process. I purchased one of the 1 st. ROPS for a yanmar & I have to say ,it is a better design than I could have made in my shop. In the test process they were able to know where to install the thickest steel & critical bracing. Without the testing the adverage person just don't know. You say ,any ROPS is better than none. Not correct , the man in the linc I provided must have thought the same. It may give you a false sense of security that I have a ROPS now so I want worry so you get into a situation & your ROPS fail, but like I said before, it's your life !

 

[EddieWalker]

</font><font color="blue" class="small">( You say ,any ROPS is better than none. Not correct , the man in the linc I provided must have thought the same. It may give you a false sense of security that I have a ROPS now so I want worry so you get into a situation & your ROPS fail, but like I said before, it's your life ! )</font>

Kenmac,

You say that the guy "must have thought the same." You are basing your position that no ROPS is better than a home built one base on what you "think" one guy in one accident might have thought.

Others have pointed out first hand experiences with rolls and how their ROPS performed. Can you state a single instance where a person was in a roll on a tractore with no ROPS that they came out of it without injury?

To me, this is an important distinction.

Eddie

 

[MarlandS]

Not to start a fight, but the story in that link shows how everything that can be done to create an accident was done and the kid payed the ultimate price and Dad and Grandpa will forever live with the guilt

First, a certified welder should have known about welding to cast and it's limitations. I get the impression that they installed the ROPS for fit and then neglected to finish it with longer bolts and a plate on the bottom (wasn't the original lower plate there already?) It would have probably been adequate for tipping the way it was set up but not flipping, especially anchored and under power.

THEN, they had a barely experienced operator doing one of THE most dangerous things you can do with a tractor, chain ,and post. Wrapping the wheel to pull posts isn't called the widow maker for nothing, I've been operating tractors for 35 years and never would consider doing this. It's too easy to miss the clutch or for your foot to slip off.

A ROPS is an easy thing to build correctly, it's not too tough to make it safe for rolling the tractor clear over but you CANNOT stack the deck totally against yourself and expect ANY man-made structure to keep you alive.

 

[keeney]

In regards to:

"To imagine that a factory ROPS found on any modern CUT will protect you in anthing but a basic sideways roll over or lay-down isn't realistic."

Well, its best not to find out the hard way, but all OSHA certified ROPS must also supposedly provide back-flip protection.

The commercial manufacturers do spend a fair amount of effort optimising their designs to be the most cost efficient way to manufacture a structure that will still meet the minimum requirements. One optimization is to only attach at two points. Its not easy to make it reliably strong enough attached only at the rear axle, so its not something I would recommend somebody try on their "1st generation, rookie, ROPS design". Also, I would not recommend blindly copying a commercial design - it would be easy to overlook something like the strategic use of a high strength alloy or the significance of a few 1/8ths of an inch of extra thickness in a key location in a casting. It is also likely that attempting a stright copy, you will be unable to sufficiently duplicate something like some cast-in additional reinforcing in the axle or a strenght-maintaing bend with little or no collapse in square tubing.

There are lots of ways to design a structure with a lot less risk of failure and a lot less chance of having a small ommission or defect turn into a failure. Its called a robust design strategy. Some people call it overbuilding. On example is attaching the ROPs at four points to the tractor. Its a lot less challenging of a design. The stresses are much lower overall - the attachment points are all in simple compression or tension, not bending. There is some redundancy by having four points vs. two. Less precise positioning is required because the protected volume is larger. The four-post design also adds some protection from stuff being dumped back on the operator from the FEL.

As another poster pointed out, don't forget the seatbelt. Its a very important part of the design.

- Rick

 

[kenmac]

Eddie, this is only one instance . DO you think this is the only accident out there where someone has fabed. their own ROPS and it didn't hold & someone was seriously injured or killed ? If you think so then you are badly mistaken.This is the only one that I happen to find & post do a google search on this subject ,I'am sure you will find many more. Eddie , if you want to build you something out of sheet metal & glue it togher with super glue & call it a ROPS it's ok with me . Just don't put someone elses life at risk because you think build a better ROPS than one that has been tested & certified. Yes look on the yanmar forum ,there is sa post there where someone rolled their tractor with no ROPS without getting injured. All it takes is a little searching & you too can find these things . As far as I'am concerned , I'am through with this subject.

 

[Slamfire]

My Mitsubishi D 1800 has a couple of flat pads with bolt holes on the rear axle also, they are for mounting the fenders, in either one of two positions. I wouldn't dream of attempting to attach a ROPS to them. The installations I've examined in junk yards had heavy plates, bolted through all four corners, with additional attachments to the frame of the tractor. I rolled my tractor once, the exhaust stack prevented it from going onto the top. I just installed dual wheels to prevent that, and am still quite leary of side hillin'. I don't know what else I can do as Mitsubishi doesn't have any aftermarket ROPS available for my model. I've only the use of one eye so weldin' my own is out of the question, and all the local welders have turned me down. Let me know how you decide. /forums/images/graemlins/confused.gif

 

[EddieWalker]

kanmac,

Obviously you make some good points. If I implied that there
has only been one instance of an injury from a home made ROPS, then that was wrong of me and I apologize. I'm sure there's dozens and dozens of times this has happened.

This is a discusson on theory and opinions based on the original post of weather it would be better to build a ROPS, to modify a factory one to fit, or not have one at all.

If you can find a factory one, then I agree that would be the best avenue. No question about it. But your position that not haveing one at all is somehow safer contradicts the events that happened in your link. That accident was destined to happen with or without ROPS. Would they have done all those things they were doing if they didn't have the ROPS? My guess is yes.

There's no need to get upset with me because I disagree with you. It's nothing personal on my part. If something doesnt' exist, then create it. That's just me. You have a different way of doing things and that's wonderful too. Just not my aproach in life.

Sorry your through with the discussion, I've enjoyed reading yours and everyone elses views on the topic. All my tractors have factory ROPS and it's something I don't ever expect I'll need to worry about for myself.

But to be able to discuss a topic with such oposing and various views is fun for me along with educational.

Thank you,
Eddie

PS, what would you do if you had an old tractor without any ROPS and couldn't find a factory unit for it?

 

[cleatus]

I've enjoyed this discussion and I knew that there is no way we'll all agree on this subject,as even the gov's cain't. THe reason they got involved at all was to slow down law suits that were putting bussiness into bankruptcy that were supporting their campaigns. I know that there was also the thought about some saffety for the consumer, but more than anything money was involved, for reelection bids and manufacters and hopfuly less bankrupties,as that also cost companys money.
The one thing I do fill strongly about is I'm safer on my none ROPS row crop 55yr old tractor with piss poor brakes than I am driving to the store, which is only 2 1/2 miles.
I know each of us feel different about saffety and each of us will normaly try to be safe with the chores we do. I also know that most people feel very unsafe holding raw edged none safety glass and this is something I do most every day, without the use of gloves, but as this has been my job for years I know what I can handle.

 

[bobodu]

</font><font color="blue" class="small">( kanmac,



PS, what would you do if you had an old tractor without any ROPS and couldn't find a factory unit for it?



)</font>

You simply don't put yourself in a situation where an accident is LIKELY to occur.I saw a program on one of the learning channels about how accidents happen.Almost always,more than ONE thing has to go wrong...ie: brakes fail,poor maintenance,following too closely and excess speed.
If I read the single article cited correctly,the kid would still be alive IF..
The tractor wasn't pointed uphill
or..
He was doing something stupid like wrapping the tire.
or...
The darned post wasn't so firmly set..
or..
The bolts were longer.
or...
He was a little more experienced and wouldn't have tried this stunt.
My point is....I don't fly kites in a lightning storm nor do I clean a loaded gun.

 

[toy]

I have been reading this thread , but I never read the attachment of the tractor accident until tonight. According to what I read it wasn't the rops that failed it was the mounting points of the rops that failed . That was a sad thing that happened and Im sure the dad and the grandad will always be saying what if I had done it this way or that way, but what we need to consider and get from this topic is that when we add something to the tractor to carefully study all aspects of the job before we do this. This is one of a many tractor rollovers that had tragic end but I figure that there have been many that have happened where no harm was done where homemade rops have held up and saved lives . This thread has given me something to think about [it's a learning experience] take your time and consider all aspects of what your going to do ahead of time research the how toos of what your doing. One says you can build your own rops the other says not to its not safe, what I learned from this you can build your own rops its doable but be very carful and if you feel the least bit intimidated about building or question your ability of doing so leave it alone and get someone that knows what they are doing to do it for you whether it is a factory rops or a home built one.

 

[JustGary]

I looked carefully at my Kubota L2800 yesterday evening. The ROPS attaches only to the rear axle, in a fashion very similar to that in the accident report. Does that mean my tractor is not safe? Yup. I can only hope that I never get the opportunity to field test its ROPS. Well that's not exactly true; I can try really hard to not test it. That beats hope every time.

Show me any ROPS you can dream up and I'll show you a situation where it could fail. Granted, my failure mode might not be a "roll over," but that giant log shouldn't crush you when it falls on you, should it? Every engineer works within design constraints, even if they are back yard engineers. Had anyone asked me about the one in the report, I probably would have declared it safe for any rollover. Would that make the death my fault? I don't think so. What we don't know about the accident is how much power the boy applied to cause the rollover. The bar might have supported a simple rollback, but perhaps the boy popped the clutch at full throttle. We don't know.

If that tractor had had a hydro transmission, the boy would probably still be alive. Does that mean we need to ban gear transmissions? Of course not. Forget the transmission, tractors aren't safe... should we ban THEM?

I would not hesitate to build my own ROPS for a tractor that didn't have one available. Would it be bullet-proof? Probably not, but it would sure beat what's on the tractor now. If I sold the tractor and was worried about the ROPS, I would remove the it and sell it to the guy separately and make him put it on. I would call it a "canopy support" too.

Regards,

Just Gary

 

[toy]

Like I said it wasn't the rops that failed it was the mounting points that failed as evedenced by the pictures. I asume that at some point there had been a rops on it previously but had been taken off, when it was taken off was something else also altered on the machine and I beleive there was something about shorter bolts that was used than what was supposed to be used and or maybe the wrong grade bolt. In an ideal world they could have found a machine like that and checked out their rops and checked other rops on other machines to see how they were mounted. I think someone in this thread mentioned mounting the rops to the frame on their machine that sounds like the safest and best way to mount a rops if it was possible. I know that those folks are heartsick over their loss. Its good to be reminded to be cautious when you are working, but not so much that you become paralized by caution and cannot do anything.

 

[keeney]

One point I think is pretty clear here is that designing safety equipment is typically a one-shot deal. Most people cannot afford to to test their tractors to destruction or failure, so the only valid design strategy is to try and anticipate the worst cases and over-build it.

All of us who have read this thread would certainly take back-flip protection into consideration if we designed our own ROPs. What would we still be missing?

What about seatbelts? Anybody ever design one of those before? They are as important as the ROPs in this protection strategy. What size webbing? What to anchor it to? What angle to the seat? What about the seat itself?

Lots of design decisions that would take a lot of thought to get it right. In addition to careful thought and consideration, a lot of these things are decided through corporate experience, testing, and unfortunately, learning from previous failed designs.

In order of safety:

1. Buy a tratcor with a full 4-post, commercially available FOPS / ROPS or cab and seatbelt.

2. Buy a tractor with a 2-point ROPS roll bar and seatbelt.

3. Buy a factory-designed add-on ROPS for a tractor without a ROPS.

4. Carefully fabricate a self-designed ROPS for a tractor without a ROPS

5. Poor ROPS design that only protects in 50% of cases.

6. No ROPS

- Rick

 

[drmiller100]

Again, I'll submit involve a local person with experience in helping you design it.
Drag racers really do have good practical knowledge in building roll over protection. There are tried and known materials.
A simple roll bar has 4 mounting points. 4 mounting points means the structure will be tension/compresssion, not bending. Take a straw, and try to bend it. Pretty easy. Now take that straw and try to pull it apart. Much much harder.

 

[Paddy]

Your point is good. Have someone design it who has exp.

In addition; I'm a test engineer in the ele field. First, all designs that will be produced in high numbers will be made of the lowest cost method! Passing the ANSI, American National Standards Istitute, test; who said it passed on the first time! And if you think the item you just bought represents...exactly what was tested, your kidding your self. In fact test don't always represent field duty, how could they with all the options for problems. Tests are descibed in 3 types, Design tests, Conformance tests and Routine tests.

I have seen products retested, SAME DESIGN, 3 times to pass. Most likely the products going out the door look like the ones that did not pass.

In summary, it is tough to match a factory design with such thin guage materials and pass the same tests. So if you want to build a ROPs, don't copy one, exceed what you see!

patrick