[AT] Who can apply for this? - a LONG dissertation on ROPS, old tractors and engineering/physics!

Fri Oct 1 16:00:58 PDT 2010

Grant is absolutely correct. In addition, in the operator manual of 
every recent tractor, it clearly states that, for the ROPS to work, the 
operator MUST be wearing the seat belt. I know that it can be a pain to 
put on and take off, but if you flip the tractor with a ROPS and don't 
have the belt buckled, you stand a good chance of being pitched on your 
head. With the ROPS in place, the worst that will happen is that you 
will end up hanging upside down and held by the belt. In fact, for those 
tractors with fold-down ROPS, the instructions say to NOT use the belt 
when the ROPS is folded down, for obvious reasons.

I understand that when some of the tractor manufacturers tested ROPS 
retrofitted to their earlier tractor models, the found that there was no 
feasible way of retrofitting ROPS, without doing major (very expensive) 
reinforcements to the axle housings.

By the way, with all of the modern skid steer loaders I worked with, the 
operator cannot even start the engine without the safety belt or bar 
engaged.

Mike

On 10/1/2010 6:33 PM, Grant Brians wrote:
> The problem with comparing loader attachment with a roll-over usage is both
> in the nature and quantity of the weight impacts. A loader in relative terms
> is a static load applied slowly. By this I mean that the quantity of weight
> is limited both by bucket size and hydraulic cylinder lifting capacity. The
> absolute limit for weight would be the hydraulic cylinder capacity, but the
> practical limit to weight would be whatever fits physically on/in what is
> attached to the tractor. A typical loader will lift no more than 2000 pounds
> and even with generated torques of position, there is little if any shock
> load to the components of the loader. If there are particularly weak spots
> in the design of the tractor (such as where the Isuzu engine block attaches
> to the bell housing of a Massey Ferguson 1180 - I speak from experience on
> this one...) then the stresses are generally concentrated in that spot. So,
> typically the loader shocks only occur when moving and are hardest on places
> where diffferent parts of the tractors are connected.
>       In the case of a ROPS, the measurements are different. The ROPS must
> not deform for a certain period of time (long enough for the operator to
> "fall" and not have their head in the position where the ROPS would deform
> to) and then support the full weight of the tractor in an inverted position
> from a shock loaded impact point. In short, the amount the ROPS must take in
> shock load is equal to the momentum of the tractor plus the weight of the
> tractor times its speed. Clearly this is a much larger load than the weight
> of the tractor.
>       An interesting story illustrating this relates to an engineering
> "stunt" pulled by my favorite car company in 1935. The 1935 models were the
> first of the larger car makers in the industry to have an all steel roof and
> roof structure on a full car line. So, first to test the design and then
> later for advertising purposes the engineers turned over their new cars and
> loaded them on top of the roofs of identical model studebaker cars. Picture
> a mirror image as in a photo trick! Then they drove the right side-up cars
> around at the Studebaker test track for the cameras. In this manner they
> pioneered consumer acceptance of a steel, not wood and fabric roof for the
> non-convertible cars. Up to this time all of the major car makers were using
> coachwork techniques for their passenger car roofs because they were the
> traditional thing to do and had been cheaper prior to the general time
> period. But Steel technology had evolved to the point where the all-steel
> designs became mass-production practical and this was the sales pitch to get
> customers to buy them - safety.
>       So there is the antique reference in this whole discussion! Also, when
> I flipped my Caterpillar D4 many years ago, a ROPS would not have helped as
> the disk behind it and the low center of gravity were what stopped the
> tractor from going over onto me - I released the hand clutch and jumped
> clear in case it were to flip further than the 90 degrees it turned over. I
> suppose the 2mph speed could also have helped?
>
> -----Original Message-----
> From: at-bounces at lists.antique-tractor.com
> [mailto:at-bounces at lists.antique-tractor.com]On Behalf Of charlie hill
> Sent: Wednesday, September 29, 2010 7:37 PM
> To: Antique tractor email discussion group
> Subject: Re: [AT] Who can apply for this?
>
>
> Carl,  if I ever do get around to building one I will not call it a ROPS
> because you can't legally do so without subjecting it to all sorts of
> testing but I would like to build perhaps a "canopy frame" or something.
> The D series AC tractors are inherently pretty stable.  The primary thing I
> would want the frame for is to give me some protection from tree branches
> and vines when bush hogging, etc.  I had the same thought about the axles
> not being strong enough, however, if they will support a front loader frame
> they should support a roll bar.
>
> Charlie
>
> --------------------------------------------------
> From: "carl gogol"<cgogol at twcny.rr.com>
> Sent: Wednesday, September 29, 2010 8:09 PM
> To: "Antique tractor email discussion group"<at at lists.antique-tractor.com>
> Subject: Re: [AT] Who can apply for this?
>
>> Charlie-
>> I wondered that myself, but no one has gone to the trouble of trying to
>> get
>> one certified.  Seems like there are a lot of D series and even into the
>> early 3 digit numbered series ACs that would have made a retro rops a very
>> attractive accessory for some small company to manufacture, if it was
>> possible.  I even went to a meeting where the safety people got a group of
>> us together (those who had tractors that didn't have available ROPS kits)
>> where I was told by one of the ag safety engineers that some tractor
>> designs
>> were flawed from the standpoint of the axles being likely to break off
>> during a  turnover event.  He did not get specific as to makes and models,
>> but was perhaps implying that was the problem with attaching a rops to the
>> axles.  I would have retrofitted if available, but am not particularly
>> worried about a rollover on my mostly bottom land farm.
>> Carl Gogol - Manlius, NY
>> Tasty grazing in the Oran valley of Central NY
>> AC D14, 914H
>> JD 5320 MFWD
>> Kubota F-2400, B7300HST
>>
>> ----- Original Message -----
>> From: "charlie hill"<charliehill at embarqmail.com>
>> To: "Antique tractor email discussion group"
>> <at at lists.antique-tractor.com>
>> Sent: Tuesday, September 28, 2010 7:53 PM
>> Subject: Re: [AT] Who can apply for this?
>>
>>
>>> Carl,  If I'm remembering right,  there is a "boss" (for lack of a better
>>> term) under the axles of D-14's right about where the fender fits on.  It
>>> has a couple of holes in it and I always figured they were for mounting a
>>> loader or something.  I've often wondered if it would be possible to bolt
>>> a
>>> bracket of some sort to that spot and mount a roll bar to that.
>>>
>>> Charlie
>>>
>>> --------------------------------------------------
>>> From: "carl gogol"<cgogol at twcny.rr.com>
>>> Sent: Tuesday, September 28, 2010 7:40 PM
>>> To: "Antique tractor email discussion group"
>>> <at at lists.antique-tractor.com>
>>> Subject: Re: [AT] Who can apply for this?
>>>
>>>> This program has been available in New York for about 5 years, the only
>>>> problem is that there is no workable design for older AC tractors.
>>>> Carl Gogol - Manlius, NY
>>>> Tasty grazing in the Oran valley of Central NY
>>>> AC D14, 914H
>>>> JD 5320 MFWD
>>>> Kubota F-2400, B7300HST
>>>>
>>>> ----- Original Message -----
>>>> From: "David Rotigel"<rotigel at me.com>
>>>> To: "Antique tractor email discussion group"
>>>> <at at lists.antique-tractor.com>
>>>> Sent: Tuesday, September 28, 2010 5:44 PM
>>>> Subject: Re: [AT] Who can apply for this?
>>>>
>>>>
>>>>> Does anyone know if this is part of the OBAMA stimulus/hand out
>>>>> package? Does anyone know how a roll over bar can help "to prevent
>>>>> tractor rollovers?"
>>>>> Dave
>>>>>
>>>>> On Sep 28, 2010, at 2:12 PM, Dave Ernst wrote:
>>>>>
>>>>>> CABOT, Vt. (AP) - A rebate program aimed at helping to prevent tractor
>>>>>> rollovers is expanding to Vermont and two other Eastern states where
>>>>>> hilly
>>>>>> terrain can be deadly to farmers.
>>>>>> The program, which is already under way in New York, reimburses
>>>>>> farmers 70
>>>>>> percent of the cost of buying a roll bar and seat belt kit, saving
>>>>>> them up
>>>>>> to $765.
>>>>>>
>>>>>> Tractor rollovers are the leading cause of death on farms and
>>>>>> officials say
>>>>>> the Northeast has the highest number of them. On Tuesday, agriculture
>>>>>> officials gathered on a farm in Marshfield, Vt., to urge farmers to
>>>>>> apply
>>>>>> for the rebates.
>>>>>>
>>>>>> The program also will be expanded to Pennsylvania and New Hampshire.
>>>>>>
>>>>>>
>>>>>> Dave
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