ROPS Tubing: Drilling Holes

[RoyJackson]

A hole in the center one direction is at the edge in the other direction. So as long as everyone knows if they are going to roll it to the side or flip over backwards in advance, you are all set. Seriously, I doubt small holes will make a hill of beans of difference. I just like U bolts for things like this, but to each his own.

Your first statement makes no sense.
The ROPS is either square or rectangular tubing. Drilling a hole in the center will not be at the edge of the other direction. Before you respond, draw a sketch of the ROPS cross section and I think you'll see what I mean.

 

[KennyG]

Well, technically he is correct that a hole in the center in one direction is at the edge in the other direction, but that's not the point. The resistance in bending is in the portion of the square tube that is parallel to the force. The hole can always be in the center of this section.

 

[Leejohn]

Good lord people get a grip, they will be printing instructions on toilet parer for some of you next!

There isn't any instructions but there is a warning! Use from front to back not back to front.

 

[TomSeller]

......

 

[RBA50]

If you're concerned a few small neatly drilled holes may weaken your ROPS, consider also the ROPS structure is only rated for the weight of the tractor & not any extra weights/ballast you may have added nor attached 3PL implements or that FEL...............

Absolutely not true.

Kubota, and I'm reasonably sure most or all other manufacturers state very clearly in their manuals for both tractors and attachments such as FEL's, that they recommend use of ROPS or CAB and seat belt in almost all applications. The exception being if there is an overhead clearance condition.

If they hadn't engineered the ROPS for use with FEL's or other implements, they would clearly state that it is not effective for those uses. Otherwise the lawyers would have their collective butts in a giant sling.

 

[MBTRAC]

If you're concerned a few small neatly drilled holes may weaken your ROPS, consider also the ROPS structure is only rated for the weight of the tractor & not any extra weights/ballast you may have added nor attached 3PL implements or that FEL...............

Absolutely not true.

Kubota, and I'm reasonably sure most or all other manufacturers state very clearly in their manuals for both tractors and attachments such as FEL's, that they recommend use of ROPS or CAB and seat belt in almost all applications. The exception being if there is an overhead clearance condition.

If they hadn't engineered the ROPS for use with FEL's or other implements, they would clearly state that it is not effective for those uses. Otherwise the lawyers would have their collective butts in a giant sling.

"Absolutely not true" ??? - Do you have an engineering basis for making such an all encompassing definitive statement or is this merely your supposition derived solely from your Kubota manual ? Unfortunately if it is the latter, best not to place too much faith in generic statements in manufacturer manuals.....

Firstly consider the physics involved in a simple roll over - a drop of only 30inches on to soil will generate an impact at least double the gross mass of the machine, additional speed, greater momentum, &/or fall or then the impact mass will exponentially increase (as will impacting a hard surface like concrete or trees during the fall) - correspondingly multiple, any prior impacts or metal fatigue will have weakened the ROPS structure

With manufacturers commonly only rating ROPS structures to approximately double the mass of the bare tractor, at much above a static roll over the performance of the ROPS structure is already marginal - Australian Standards AS1636 & the International Standards on which they are based allow for construction of ROPS to the extent of structure deformation/survivabilty only to the extent to reduce the risk of fatal injuries for the operator if the tractor rolls in a low speed single roll over situation, rated for the bare tractor only - with the additional weight of any linkage implements, trailed attachments &/or a FEL the ROPS design intent/standard is well exceeded.......

Consider also the attached practical example of ROPS performance in combination with considerable dynamic loading, an investigation into a fatality caused by ROPS deformation under static loadings well within this specific tractor was rated - this 180hp tractor of 8.1T, with a 3PL capacity of 6.4T & rated for a 3.7T FEL (not fitted) experiencing a catastrophic ROPS deformation when the only additional weight on the tractor was a 7.8T trailer - Tractor roll over protective structure limitations - Workplace Health and Safety Queensland ..........all weights are well within the parameters of the manufacturers tractor operation manual & ROPS certification .........may be a 180hp tractor but the same ROPS design principles/limitations apply to 18hp tractors.......

 

[npalen]

I've often wondered if an operator who is not using the lap belt on a ROPS tractor is in more or less danger during a rollover than if there was no ROPS.

 

[RoyJackson]

I've often wondered if an operator who is not using the lap belt on a ROPS tractor is in more or less danger during a rollover than if there was no ROPS.

Good question...I can't say I have the answer, but I do think it would be quite ironic if the operator was crushed under the ROPS when attempting to jump.

 

[mjncad]

My JD 4200's operator's manual clearly states that if the ROPS is down, then do not wear the seat belt to give yourself a chance of survival by jumping clear of the tractor. If the ROPS is up, use your seat belt to remain within the "zone" to speak and avoid being crushed.

 

[Midniteoyl]

I have responded to this many times in the past and will say again, if the ROPS is so weak that putting a 1/4-1/2" hole in in compromises the safety then it isnt designed properly to start with. With the middle of the ROPS bracket being the area with the most force in a roll over (just like the center span of a bridge or building truss) this would be the area to avoid drilling holes. Upper or lower ends would be better if you are concerned. The same goes for welding on them. If you dont undercut the area welded on then you strengthen the area rather than damage it. Most folks here on TBN talk like the ROPS is a space shuttle or something. FOLKS its just a piece of common steel tubing bent to shape with mounting attachments WELDED on. Not exotic material, not special in any way other than designed to stop the weight of the tractor from continuing to roll and tested to verify. It will bend in a catastropic roll over just like any other piece of steel but should protect the operator from getting crushed if he is belted in. ROUND holes dont contribute significantly to strenth reduction where as anything with a corner is bad as it gives a good starting point for a crack to begin.

One other thing, if you think you can sue a ROPS manufacturer for something after a roll over, think again. They arent responsible for the roll over, you were. If the operator gets hurt because the ROPS bent, then YOU exceeded the limits of the protection. You cant drive a car off a 100' cliff and then sue the manufacturer because the air bags and safety harness didnt keep you from getting killed.
This is my opinion and all you safety freaks can flame away with your opinion which is all it is. No one has produced anything showing that drilling a hole compromises the integrity of the ROPS other than opinion. With all the engineers here, I would have expected someone to have calculated the effects of a hole on reduction of strength in at least a typical sized ROPS frame for CUT's.

And, i totally agree!!!

Just how many car, truck, motorcycles, or even, god forbid, airplanes have holes drilled in the structure?