ROPS Tubing: Drilling Holes

[PILOON]

And, i totally agree!!!

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

Most airplanes wing ribs and other parts have more holes than not, some cases more than 50% holes.
HOWEVER aviation workmanship calls for de-burring and removal of any nicks around edges of holes. A simple nick can start a crack due to vibration and constant flexing which in case of a ROPS would not be a factor.
Critical components such as landing gear are actually welded as are many engine mounts.
It is all in the quality of the workmanship.

 

[RoyJackson]

Most airplanes wing ribs and other parts have more holes than not, some cases more than 50% holes.
HOWEVER aviation workmanship calls for de-burring and removal of any nicks around edges of holes. A simple nick can start a crack due to vibration and constant flexing which in case of a ROPS would not be a factor.
Critical components such as landing gear are actually welded as are many engine mounts.
It is all in the quality of the workmanship.

The holes in wing ribs and other structural members are for lightening purposes...since many of the holes are flanged, they stiffen the structure as well.
Good point about deburring all holes and other edges.

There's little doubt in my mind that a few small holes in the ROPS won't result in a catastrophic failure...however, when a manufacturer certifies a ROPS, they're actually certifying the design. Any changes to that design would require re-certification/validation.
Also, if the manufacturer did not prohibit any modifications to the ROPS, some fool would drill, weld or make other modifications that would degrade the ROPS. It's all a matter of liability...

 

[hosspuller]

"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 .... .

Interesting link ... A question about the trailer in this accident..

"...Significant contributing factors to this incident were the speed and mass of the tractor and trailer combination, as well as the use of castor steering (shopping trolley steering) on the front axle of the trailer. ..."

Does this mean the front wheels of the trailer (assuming 2 front 2 back) are free to swivel? Or are they speaking of typical Hay wagon steering ? (Trailer tongue steers the front wheels)

 

[Midniteoyl]

Most airplanes wing ribs and other parts have more holes than not, some cases more than 50% holes.
HOWEVER aviation workmanship calls for de-burring and removal of any nicks around edges of holes. A simple nick can start a crack due to vibration and constant flexing which in case of a ROPS would not be a factor.
Critical components such as landing gear are actually welded as are many engine mounts.
It is all in the quality of the workmanship.

Agreed...

 

[Midniteoyl]

The holes in wing ribs and other structural members are for lightening purposes...since many of the holes are flanged, they stiffen the structure as well.
Good point about deburring all holes and other edges.

There's little doubt in my mind that a few small holes in the ROPS won't result in a catastrophic failure...however, when a manufacturer certifies a ROPS, they're actually certifying the design. Any changes to that design would require re-certification/validation.
Also, if the manufacturer did not prohibit any modifications to the ROPS, some fool would drill, weld or make other modifications that would degrade the ROPS. It's all a matter of liability...

So every time one drills through a firewall, frame, or other part of their car, trailer, bike, etc, they are invalidating the OEMs design? Can the OEM (and insurance) then deny any liability? How many has this happened to?

 

[RoyJackson]

So every time one drills through a firewall, frame, or other part of their car, trailer, bike, etc, they are invalidating the OEMs design? Can the OEM (and insurance) then deny any liability? How many has this happened to?

If the manufacturer states (in the manual) to make no modification, then the risk is on the person that does make modifications.
As far as your comment "firewall, frame, or other part of their car, trailer, bike, etc,"...if it's safety related (frame might be an example, but the firewall probably wouldn't be a safety related component), then the manufacturer could deny responsibility based upon those changes.
As I wrote...it's a matter of liability...that, and frivolous lawsuits against a manufacturer.
Also, as I wrote...some fool would turn his ROPS into Swiss cheese, then sue the manufacturer because it failed in a rollover.

 

[yelbike]

Common sense needs to apply. Drill and tap for a #8 screw, your good. Drill a 2" hole to pass your wire through the ROPS well that excessive.
On my JD 2305 I had my ROPS cut and added folding feature to the ROPS. If it fails in a roll over, my wife can not sue JD for a bad design.
Let's use common sense.

 

[Midniteoyl]

Also, as I wrote...some fool would turn his ROPS into Swiss cheese, then sue the manufacturer because it failed in a rollover.

True...

 

[WTS Tractor]

Exactly what my dealer says. Never had a problem with a lawyer wanting to sue somebody because there was an extra hole in the ROPS bar

 

[PILOON]

"Let's use common sense."
Unfortunately not all judges possess that commodity, nor do they comprehend mechanical subjects.
You would be wide open for a battle of experts. A judge simply interprets a law as he best sees it.
Could quote many examples that simply boggle the mind.
As an example,buddy had $8K damage to his tractor due to faulty installation by dealer. Happened again 10 hours later and dealer re-billed additional $4000 repairs. Buddy sued, took 2 years to get to court and he had as an expert the firm that manufactured the attachment .
Final ruling was in his favor but due to delays he lost tractor usage for that period of time * and the lawyer's fees ate up the settlement.
The only win was in principle.

* dealer held tractor hostage for 2nd bill as buddy refused to pay 2nd bill that was in essence correcting initial faulty installation and should have been dealer guarantee.
Adding insult to injury dealer was billing storage of tractor that he held hostage.