You tube link re: kinetic recovery straps

[andrewk]

I is my opinion that when a vehicle is stuck in the mud it is best to leave it where it is until the 'sun comes out and dries up all the rain!'

Nah, there's a much better way than that. I was ever so slightly traction challenged on an uphill muddy slippery lane last time out with a few friends who are members of Manchester GLASS (this time it was 100% a tyre problem). As the BFG MT tyred Defender 90 in front of me had struggled to get up the same stretch of track too, it wouldn't have been entirely sensible for him to reverse back and try to recover me with a rope, else we might have had two vehicles to recover.

We did consider leaving the Patrol until the sun came out (but only for a couple of seconds). It's amazing how effective half-a dozen strong chaps can be shoving even a Patrol. :smile: :smile:

Cheers
Andrew

 

[JonathanM]

Sorry Andrew, but can you define "gentle recovery"? Any recovery will result in forces and loading beyond expected, and other than a very gentle "tug" will place a significant load on recovery points. A heavier vehicle such as yours is even less likely to be subject to a "gentle recovery".

Why mention a KERR? Because they are in use out there, and one practicality - if you were laning with this club, in the absence of another patrol or a discovery, then a SWB Terrano such as mine may have to resort to a KERR recovery in the event of you becoming stuck. Simple physics of a vehcile with a kerbweight in the region of 1700kg having to recover a stuck vehicle in the region of 2300kg in an off road situation.

A 50mm towball is the bottom of the recovery point ladder. Anything that secures the strop/strap/KERR more effectively is safer. And shackles around a towball is a no-no, regardless of what load the shackle is rated to. This is what will cause a towball to fail, the load is concentrated at the weakest point of the towball - the neck.

The link you post actually highlights the problem of any towball in that a strap placed over the ball could slip off, and it is the shank type towball as used in Aus that is the type mentioned in my link as failing.

It would be much safer to obtain a "jaw & pin" type of bracket. Much more secure in terms of the strap being unable to slip off, the angle of the pull will not increase the risk of a strap slipping off.

 

[andrewk]

Sorry Andrew, but can you define "gentle recovery"?

Anything needing only a gentle tug using a towstrap, where the stuck vehicle has lost traction on a hill, slippery surface or in relatively shallow mud. I do not mean recovering a deeply stuck vehicle from thick mud. We shouldn't be driving a lane like that in the first place. It's behaviour like that which gave the anti-brigade the ammunition to push the RoW section of NERC through parliament.

The link you post actually highlights the problem of any towball in that a strap placed over the ball could slip off.

You seem to have missed or ignored its main thrust, which is that using a shackle that locks over a towball is often a safe option and often stronger than many recovery points provided on 4x4 vehicles. Admittedly it's a promotional document, but their test results, if not invented, are hardly debatable.

I have still not seen any evidence of a 50mm towball disintegrating during recovery, as you have claimed. The link you provided was about snatch recovery and provided no detail about the towball failure. The disintegration of a towball may or may not have occured. Nothing in the article suggests that it did. Is there no better proof of your assertion?

Cheers
Andrew

 

[JonathanM]

Andrew, please give me an indication of what level of proof you wish me to provide - you seem to require a still warm body to prove the point.

 

[jace]

i see the point off it being thinest part the tow hitch but would the straps etc not take some stress outve the initial pull giving it bit easier time ive no exsperiance of these things so bow to greater knowledge!

 

[JonathanM]

I'll bow to Andrew and go with a towball being suitable for use with a shackle in off road recovery situations.

 

[Terranosaurus]

I'll bow to Andrew and go with a towball being suitable for use with a shackle in off road recovery situations.

Absolutely Jonathan, what could be better, brittle cast iron with point loading, spot on, just the ticket - I'm off now to make a house of straw.

 

[JonathanM]

I'll bow to Andrew and go with a towball being suitable for use with a shackle in off road recovery situations.

Absolutely Jonathan, what could be better, brittle cast iron with point loading, spot on, just the ticket - I'm off now to make a house of straw.

Why not build it on sand while you're at it :smile:

 

[(RIP) PLANK]

I am dubious about tow balls as recovery points with a shakle as well, but I remember years ago being critiscised for not using the tow ball when recovering a land rover with a land rover!

anyway, I have witnessed a shackle on a tow ball recovery of a 4.2 patrol by a discovery (you know who you are) and I thik still have a photo some where.

I would imagine this is a situation that gets worse the more you do it as you have said it is the ball that is designed to take the streain not the neck!

I still beleive having a strap that is not 'over rated' is a good step to make sure it is the weakest link in the chain rather than the tow ball, recovery point etc.

I have had a few ropes and a couple of straps fail and none were catastophic, just dropped un eventfully to the ground!

 

[jace]

i remember trying to pull some tree roots out with van strap snapped shackle hit house oposite knocked hole in cladding luckily no one was home and we missed the windows! did bit more diggin after that!

 

[andrewk]

Andrew, please give me an indication of what level of proof you wish me to provide - you seem to require a still warm body to prove the point.

I have provided links to an article by David Bowyer on Difflock (an authority on offroading) that supports the notion that using a towball as a recovery point is a reasonable thing to do - and also to an article that proposes the use of a locking shackle on a towball as a safe and strong means of recovery. The article contains test results that support the notion that a towball can provide a stronger recover point than is usually provided by recovery hooks often installed as standard on 4x4 vehicles. The article also provides support for the strength of materials data that I posted earlier which indicate that disintegration of a towball is unlikely to occur.

Up tp press, you have made a few assertions about the unsuitability of a towball as a recovery point for any kind of recovery and have provided only a single link to an article that doesn't provide enough detail to support what you have said. I would certainly be interested in any documented cases of towball fragmentation that inform your views. I certainly haven't seen any.

Cheers
Andrew

 

[dinky]

Allways thought the idea of the towball ,was a pivot point,which joined the vehicle and trailer.Not as a recovery point.In the paperwork for my ALKO hitch it states unsuitable as a recovery point Why do we use them because its easier to loop it over,ive done it.Dinky -banghead-

 

[jace]

have to admit put some stress on towballs trying to drag alsorts without failure although in cold weather metal is more brittle

 

[Terranosaurus]

Andrew, please give me an indication of what level of proof you wish me to provide - you seem to require a still warm body to prove the point.

Andrew I have to agree with Jonathan

"The deaths of two Queenslanders in 2003 and 2005 during attempts to recover bogged vehicles highlight the potential hazards of using elasticised snatch straps.

"In one case a snatch strap catapulted a dislodged towing hook, striking the victim in the stomach.

"The other death occurred when a tow ball was sheared off during the recovery process and struck a man in the head."

Seems pretty self explanatory to me.

David Bowyer cannot see past the green oval badge, his advice is often totally inappropriate to other vehicles, such as driving in high gears, no use at all in a small engined vehicle like an SJ. Landies are often fitted with better quality towing hitches, dixon bate style with teel pins etc, but even he does seem want to use them only when nothing better is available which on a std landy there isn't, most of us have an option.

Why attach to the cast iron tow ball when in many cases you can attach to the steel assembly that supports it.

 

[andrewk]

Seems pretty self explanatory to me.

Nope - you are just trying to fit an article to a point you wish to make. It does not say that the towball disintegrated - it may well just have have parted company with the rest of some old rust-bucket, as can happen with any kind of recovery point. It just doesn't say.

David Bowyer cannot see past the green oval badge, his advice is often totally inappropriate to other vehicles

Others can form their own view about that comment.

Why attach to the cast iron tow ball

Towbar flanges have sharp edges that can abrade or cut into recovery ropes - wrapping a recovery rope around one is hardly a good idea.

You should note that the Alko towball on the back of my motor is definitely forged not cast. It has a 28mm diameter neck and it would take around 30tons to make the 50mm ball itself part company with the rest of the forging. Forces of that scale are just not seen in any kind of recovery. Sealey balls are also forged. I got fed up of checking after that.

Frankly this discussion is getting tiresome. Repeating the same assertion does not make it true - no matter how many time you repeat it. If you believe that there have been widespread occurences of towballs disintegrating - i.e. the 50mm ball parting company from the rest of the towball then you should easily be able to find some proof of that. I've looked and haven't been able to find any.

There have been incidents of fatigue failure in M16 bolts if they are not torqued up properly when fitted - but this is not the arguement that is being made, is it? In any case, M16s are far less likely to fail than the M10s that often hold recovery hooks.

Cheers
Andrew

 

[thor]

All this is genuinely very interesting.
From my point of view, I wanted to know if the tow ball would suffice for a recovery.
It has now made me aware that recently when I pulled a VW Golf out of a muddy situation, using the ball, that the load would not have snapped the ball [I hope 8O ] but I should have been more aware that the recovery line could have come off.
I have decided to acquire ball and pin, and a decent strap or rope. this for me at this stage [until I can get out with you guys in those undulating lanes] will be suitable. I think [I used to be indecisive, but I'm not sure now] :smile:

 

[andrewk]

I have decided to acquire ball and pin, and a decent strap or rope.

I have an "African Hoe" combined ball/pin hitch that's rated at 3500kg on either ball or pin. They're less than £50 and look every bit as good as the Bradley or Dixon Bate equivalents. I had it fitted to my Trooper (now moved on to pastures new) partly because I wanted to tow a car using a towpole (on the pin) and partly because of its greater depth (i.e. the distance between the flange and ball centre was greater) which helped in avoiding having an Alko stabiliser hitch handle foul the spare wheel carrier when hitching up my caravan.

The combined ball/pin hitch is now sitting unused in the garage for two reasons. Firstly, I've discovered that the main difference between Alko's own towball (which I had anyway) and standard type approved balls is not so much greater depth as greater neck length - to allow rotation of the Alko hitch on the caravan without fouling the towball body - so it wasn't a great idea to use the combined ball/pin device with an Alko caravan hitch anyway. The second reason is that it hangs down below the towbar flange and further compromises departure angle - so you might end up ploughing up half of Cheshire (for example) the next time you go greenlaning - or even getting hung up on the end of the pin.

You might want to think again about the combined ball/pin device. If you really want one anyway and are going to the "beginners day" on the 30 Dec 07, I could bring along my unused one for you to try, if you want to do that. It is this one .... http://www.steeltrade.co.za/shopfronts/africanhoe/uploads/prod1_b.gif

Cheers
Andrew

 

[andrewk]

You might be interesting in this link to a Difflock thread ......
http://forum.difflock.com/viewtopic.php?t=7520&highlight=towball

It is relevant to the earlier post that mentioned an incident a few years ago in Australia. This is a quote from the thread .....

The majority of towballs used in AUSTRALIA, USA and many other countries consist of a ball and 'neck' or shank which is threaded to fit in a horizontal hole. A single nut is tightened on the shank to hold it down.

THIS TYPE of Tow ball IS NOT suitable for heavy recovery for the reasons stated.

HOWEVER the standard 50mm ISO towball used in UK and other countries, which is a larger cast item secured by TWO very large bolts IS suitable for recovery which is why it is listed as acceptable in many offroad competition regs.

Q.E.D.

Now, can we talk about something else?

Cheers
Andrew

 

[(RIP) PLANK]

I must admit i am persuaded towards the tow ball idea, as you say it seems more likely that the tow bar will fail than the ball, and many recovery points on vehicles look as if they were designed for towing it ont a recovery truck when it breaks down on the road. Theyare surely made of mild steel welded to a mild steel chassis?


Are tow balls made of cast iron these days? i though they would be cast steel surely? even all the fittings for gates and railings are cast steel now, isnt cast iron a little out of date?

Also arn't all the tow balls on cars now tested and approved to a given standard (post 1998 I think) I still agree the strap simple looped over could come off but even in this senario, would a loose strap cause that much damage?

 

[andrewk]

I must admit i am persuaded towards the tow ball idea

I'm not trying to persuade anyone that using a towball for recovery is the best thing since sliced bread, just that it's OK if used with care - and that those with towballs on standard family motors who want to do a little gentle greenlaning don't need to rush off to spend money on a rear recovery point if they already have a towbar fitted. It's a good idea, though, to make sure that they have a solid front recovery point (Doesn't a Terrano come with a 4 ton hook as standard?) because they are more likely to need recovering than to have to recover a vehicle behind them - especially if they are on road tyres.

OTOH, if they want to do something more extreme than gentle greenlaning, then maybe they need to think again about lots of things - possibly including their choice of vehicle.

Cheers
Andrew