Why you dont use a towball for a recovery snatch.......

[Sand Runner Lurker Find all posts View Profile Close Sand Runner]

wow........lucky that didn't cause an injury / death!
Nasty business indeed!
I haven't done a lot of recovery work........my little Jimny didn't ever get stuck on the sand .........but I knew that it "wasn't an option" to use the towball in such a way.
I guess reading all the "theory" has come in handy after all

[kieranu Member Find all posts View Profile Close kieranu]

Someone used the towball on their tractor to recover me once. The family and I walked to the other side of the dune while they pulled her out just in case. I took the towball over nothing as I was appreciative of someone assisting, particularly as this was Christmas Eve, and didn't want to be stuck there any longer than necessary but wasn't prepared to die for it.

[AJ120 Out of control poster! Find all posts View Profile Close AJ120]

A couple of people have asked me for more detail on my rear recovery points.

The LHS is just bolted to the chassis. The plate for the RHS is 70mm x 90mm x 12mm, holes are at 35mm centres one way and 50mm centres the other. Holes are to take 12mm bolts. I also have a couple of packing washers between the plate and the chassis to clear the weld on the bottom of the chassis rail.



The rated recovery hooks are availble from just about any 4x4 or auto store, they are 10,000lb rated (stamped on the hook). The RHS hook still sits close to the exhaust but it is not an issue, the exhaust is not nearly hot enough at this point to cause an issue.

Cheers Andrew

[AJ120 Out of control poster! Find all posts View Profile Close AJ120]

SteveM

SHAME, SHAME, SHAME.
You should be severely dealt with and all your cudos stripped away immediately.
DO NOT pass go, DO NOT collect $200.

Why you may ask?

I refer you to your post 7 and tender this as Exhibit 1. Take a good look sir. Well, do you see the offence? Do you?

Jeffers, rags and AJ120, you are also accused of "Aiding and Abetting" this most hanest crime and the matter has been referred to the 4wding party for a suitable punishment, which means AJ120 will in fact have to hand done his own sentencing!
The prosecution rests your honour

(AJ120, I have a hurri curri sword and think it is the only honourable thing you can do.......)

As punishment for my sins I have sentenced myself to go night time 4wdriving tomorrow night down the border track

Cheers Andrew

[rags Advanced Member Find all posts View Profile Close rags]

SteveM

SHAME, SHAME, SHAME.
You should be severely dealt with and all your cudos stripped away immediately.
DO NOT pass go, DO NOT collect $200.

Why you may ask?

I refer you to your post 7 and tender this as Exhibit 1. Take a good look sir. Well, do you see the offence? Do you?

Jeffers, rags and AJ120, you are also accused of "Aiding and Abetting" this most hanest crime and the matter has been referred to the 4wding party for a suitable punishment, which means AJ120 will in fact have to hand done his own sentencing!
The prosecution rests your honour

(AJ120, I have a hurri curri sword and think it is the only honourable thing you can do.......)

Ah yes your honour but i was merely pointing out the offence to the original poster of publicly showing a recovery point that included the brand NISSAN,with the comment of Preferred method of recovery point.
It was I that in the first instance suggested that ones error should be rectified with the picture being replaced with a more suitable pic with the word Toyota. It is also noted that the original offender has now rectified the offence of replacing the said photo with the correct pic preferred by pradopoint of a toyota recovery point.
So your honour i plead not guilty and in fact would also like to claim any bounty or reward that may have been on offer for bringing this matter to the attention of others.
Russ

[Sand Runner Lurker Find all posts View Profile Close Sand Runner]

So I guess the one thing the last posting and a rated shackle have in common..............they're both legal loop-holes........

[K & M McF Senior Member Find all posts View Profile Close K & M McF]

What holds the recovery unit in the towbar? Surely it is the pin? Therefore, isn't the same part under stress from a snatch if you compare using the pin or the unit?

[MidLifeCrisis Out of control poster! Find all posts View Profile Close MidLifeCrisis]

What holds the recovery unit in the towbar? Surely it is the pin? Therefore, isn't the same part under stress from a snatch if you compare using the pin or the unit?

Uhm, no. Distributed energy is very different to localised energy. (bad choice of words but look at it like this, without the unit there is a concentration at 1 point on the pin (in the centre). With the unit there is dispersed contact AND therefore two points where the pin is stressed being the points where the pin touches the female part. I'm not a scientist so without being able to prove it I suggest the two points of contact with the female part must only have half the load and a distributed load along the pin that was previous not reinforced and therefore under more stress.

mlc

[MidLifeCrisis Out of control poster! Find all posts View Profile Close MidLifeCrisis]

Ah yes your honour but i was merely pointing out the offence to the original poster of publicly showing a recovery point that included the brand NISSAN,with the comment of Preferred method of recovery point.
It was I that in the first instance suggested that ones error should be rectified with the picture being replaced with a more suitable pic with the word Toyota. It is also noted that the original offender has now rectified the offence of replacing the said photo with the correct pic preferred by pradopoint of a toyota recovery point.
So your honour i plead not guilty and in fact would also like to claim any bounty or reward that may have been on offer for bringing this matter to the attention of others.
Russ

The prosecution notes the evidence has been tampered with!

Oh, I replaced my Toyo towbar with a HReece. Stainless steel is much safer than cast iron, as is the way its fitted.

[Jeffers Advanced Member Find all posts View Profile Close Jeffers]

Wow, that looks nasty MLC..

I'm glad the 150 has a steel Tow Bar (NOT CAST)

Cheers,

Jeff

[mjrandom Out of control poster! Find all posts View Profile Close mjrandom]

What holds the recovery unit in the towbar? Surely it is the pin? Therefore, isn't the same part under stress from a snatch if you compare using the pin or the unit?

The difference is how they are loaded. If the strap is just looped over the pin in the centre of the towbar that puts the pin in bending whereas the recovery hitch places the pin (and shackle bolt/pin) in double shear. Roughly the bending stress in the pin will be 12x greater than the shear stress from the hitch at the same load. The allowable stress in bending is about 40% higher than that for shear but even so the hitch is under way less stress than pin alone, still something like 8x effectively.

Also even if the pin under bending load doesn't fail it can plastically deform which means the pin cannot be removed from the towbar.

[MidLifeCrisis Out of control poster! Find all posts View Profile Close MidLifeCrisis]

The difference is how they are loaded. If the strap is just looped over the pin in the centre of the towbar that puts the pin in bending whereas the recovery hitch places the pin (and shackle bolt/pin) in double shear. Roughly the bending stress in the pin will be 12x greater than the shear stress from the hitch at the same load. The allowable stress in bending is about 40% higher than that for shear but even so the hitch is under way less stress than pin alone, still something like 8x effectively.

Also even if the pin under bending load doesn't fail it can plastically deform which means the pin cannot be removed from the towbar.

That's exactly what I said in post 39! Word for word

[mjrandom Out of control poster! Find all posts View Profile Close mjrandom]

Dear MLC

Ummm yes of course it is.

Can you post your calcs so I can compare notes to make sure?

Mikhail

[MidLifeCrisis Out of control poster! Find all posts View Profile Close MidLifeCrisis]

Dear MLC

Ummm yes of course it is.

Can you post your calcs so I can compare notes to make sure?

Mikhail

Pretty sure I already sent them to you in your hand writing so you can easily understand them.

[mjrandom Out of control poster! Find all posts View Profile Close mjrandom]

I'll pay that!

Also explains the errors!!

Love your work MLC.