Recovery and Towing

[antarmike]

Not really of any use but interesting any way. A chap I know who is not given to wild exaggeration, once told me that when doing a very heavy recovery job with an ARV in very low light conditions, the winch rope was starting to glow dull cherry red. :sweat:

nonsense!!!

[antarmike]

Well, I'm not sure it's so much about annoying people Mike, as questioning the validity of the whole thread :confused:

Am I annoyed? No, I'm absolutely furious :argh:

 

 

So much so that I feel compelled to make the following comments:

 

Have you really not learned in your 20 years experience that winching has the potential to be highly dangerous?

Have you never considered the possibility that you were extremely lucky with your broken rope?

The point is you shouldn't have broken it in the first place.

Was the rope damaged prior to this incident? (point already made in this thread).

You've also admitted to rigging it incorrectly (point already made in this thread)

And what about insurance / liability? I suspect that your machines are covered by commercial/business insurance - the point I made in this thread was to make people aware that IF anything were to go wrong (and thanks to some of the excellent posts, by now everyone should be aware that it could go wrong big time) someone might be held to account, so be very aware of the risks you take.

 

Have you never looked at a winch rope in appalling condition on a preserved MV and thought "Oh dear, I hope that never gets put to use"?

 

I've not had anywhere near the amount of winching experience as you, but I've had enough to be very aware of the inherent dangers, and the need to approach the task responsibly in order to minimise risks (point already made in this thread).

 

I for one thought it was an excellent subject to discuss on the forum, and 10/10 to TonyB for starting it off!

 

In my view all the posts made so far have all been very valid, and when done in the now classic HMVF style of blending good advice / relevant experiences and of course humour, the result is a well-balanced thread which hopefully will encourage any budding winchers / recovery artists to approach the task with the right attitude, and to act responsibly.

 

And if it puts off a few who may take the view that their equipment is perhaps not in the best of condition, that might not be a bad thing.

 

Please re-read your post Mike, and if you really believe that we should all post in a responsible way on a public forum such as HMVF, then PLEASE make some alterations.

 

:tup::

 

When I broke my winch rope I was working alone, putting no-one but myself at any conceivable risk. I was working, ie being paid and I had to get the job finished. Resplicing the rope, I got all the roots out without further incident. Ash trees are rooted into the ground stronger than any other tree I know, so this is extreme winching. My comments on this forum relate to getting vehicles moving on muddy grass fields, where the wheels are not sunk to the axles.

 

In this situation the possibility of winch rope breakage approaches zero.

 

Using something like a timber rigged matador, equipped with ground anchors to winch, has always in my experience reulted in the front end of the vehicle lifting or the anchors dragging. If you work out the moments of force (weight of vehicle x distance of C of G ahead of the anchors), this equates at the point of balance (when the front of the vehicle will lift) to the Force on the winch rope x the height of the rope above the bitting point of the Anchors.

 

I have worked this out many times for many different situations and I have always found the stress in the rope is well within its breaking strain.

 

The picture of the 360 digger I posted, required me to reposition my matador 10 to 15 times until I found ground strong enough to stop the Matador dragging back. I know that for a 7 ton vehicle, fitted with a 25 ton breaking strain rope the limiting factor is getting a grip on the Anchor.

 

I eventually got that grip but I was well short of the pull required to lift the front of the Matador. I say that winching vehicles that have lost traction on wet/ muddy grass is basically safe.

 

 

Re glowing winch rope, this is the sort of cr*p sensationalism I am on about. What generated the heat.? Heat is generated by friction. Where in a winching situation is friction occuring? Have you ever put your hand on a rope after winching and noticed it to be even mildly warm?

 

Wire ropes for ploughing engines used to be made of plough iron, which was not heat treated, but for all the modern winch ropes we find and use the material is alloy steel, heat treated.

 

Heat treated steel starts to loose its strength if heated abouve 300-400 Centigrade. It won't glow dull red until about 700-750 Centigrade by which time it will have lost all its heat treatment properties, probably halving its strength. If there was any mechanism by which a hard pull on a cable could heat it up, the weakened cable would have pulled apart because of loss of strength. Sensationalit cr*p...

 

No I stand by what I say because it is my opinion. We have free speech, Everyone may make up their own mind. I am not writing a book on recovery technique, but if you seek to ban winching at rallies how are you going to get a stuck truck unstuck. If you put enough vehicles together to tow it the stress on the chain or hawser will still be the same as winching. Pulling lots of vehicles together has exactly the same chance of something breaking.

 

Wthen you have problems of co-ordinating the process.

 

No I believe winching of vehicles that have lost traction on a rally field to be the safeest method of recovery, and if I had to rate it 0 -10 for safety, I would give it a 9.

 

If a vehicle was driving across a muddy field before it got stuck, the force to move it forward came from the grip between its wheels and the grass. When it hits mud it looses that grip, but the force required to get it moving again is little more than it took for it to drive, This is way within the breaking strain of a good wire rope, Think about actual facts and figures and ditch the sensational hearsay and anecdotal rubbish. Even if the force doubled it is still safe.

 

Would you have a back to back tug of war between to lorries on grass and expect a 3/4" wire rope to bust when one starts to spin a wheel... theres not a chance a lorry could pull the cable apart. Then you can use that dia rope safely to winch the same vehicle forward on muddy wet grass

 

Anyhow I have poked the hornets nest, I am now off on holiday for 3 weeks so I'll see how many hornets are still flying around when I get back, but I have no intention of re-writing any of my comments.

Edited August 18, 2008 by antarmike

[gritineye]

Re glowing winch rope, this is the sort of cr*p sensationalism I am on about. What generated the heat.? Heat is generated by friction. Where in a winching situation is friction occuring? Have you ever put your hand on a rope after winching and noticed it to be even mildly warm?

 

Wire ropes for ploughing engines used to be made of plough iron, which was not heat treated, but for all the modern winch ropes we find and use the material is alloy steel, heat treated.

 

Heat treated steel starts to loose its strength if heated abouve 300-400 Centigrade. It won't glow dull red until about 700-750 Centigrade by which time it will have lost all its heat treatment properties, probably halving its strength. If there was any mechanism by which a hard pull on a cable could heat it up, the weakened cable would have pulled apart because of loss of strength. Sensationalit cr*p... .

 

My thoughts exactly Mike, it would have failed long before getting red, but he was insistent it happened!

[gritineye]

Just thought I'd dig out the capstan rope mentioned earlier as it is still in the shed ten years on, took a couple of pix just to explain what not to do with a shackle.

 

 

 

Please note: As mentioned before, if this rope had broken it would not have whipped back along the line of the pull, because it is a rope that is designed for the job, it does not stretch and resists tangling. Most twisted ropes would have done so.

Edited August 18, 2008 by gritineye

[N.O.S.]

This is typical of the stuff I have recovered, and the pull required to move a vehicle that has lost traction on a muddy showfield ( which is I believe what we are talking about in this thread) , doesn't come close to what it takes to extricate something like this.

 

Come on, get real and stop inventing risks (or exagerating them beyond what is reasoonable)

 

I've got to say I rushed a reply to Mike's post in the hope that he would be abe to respond, rather than wait until his retun from GDSF. At least I'm glad he was able to to do so.

 

In fairness to you Mike, in the context of pulling vehicles off slippery grass (if fairly level and not dangerously sloping :whistle:) then your comments are quite valid and I am in total agreement with you (assumng that the wincher knows that his rope is in good order....).

 

However, your post is the first and only time that recovering a vehicle that has lost traction on a muddy showfield (sitting on top and not sunk to the axles) has been mentioned - the opening post asked for -

 

tips to foster good SAFE towing, recovery and winching,

 

 

and the subsequent 30 or so replies were (at least I thought so) adding up to a nicely balanced read on the subject.

 

Perhaps I'm worrying too much about other people, but I really do not want to see anyone who has never winched before pull out a "looks ok but in fact rotten" rope to help someone off a wet rally field and then think that any sort of winching is a piece of cake.

Edited August 18, 2008 by N.O.S.

[N.O.S.]

I had to ban the local landrover club from doing "snatch" recoverys (don't even start on kinetic ropes).......

 

Yes Croc, please do start on KINETIC ROPES!

 

I recently got hold of some large ones (W+P) for use as general tow ropes. Now I'm not one for snatch towing - dangerous and liable to break something.

 

Am I right in thinking these ropes are specifically for snatch recovery, where the energy of momentum is transferred from the 'vehicle accelerating rapidly away' to the stationary stuck one, but in a less agressive way than a rope or chain?

 

Are they suitable to use for general towing, or are they too bungee-like?

[Marmite!!]

Yes Croc, please do start on KINETIC ROPES!

 

 

Read this thread then.. http://hmvf.co.uk/forumvb/showthread.php?p=21909#post21909 there's a pdf at the bottom...

[N.O.S.]

Thanks Lee. So would I be correct in thinking they could be very dangerous to use as normal 'slow pull' recovery ropes then? Anyone had any experience of same?

[Stormin]

KERR always work as such.

Even if you think you are not doing a "snatch" recovery, the rope stretches a hell of a lot before anything begins to move. This gives the false sense that lower force is involved than when using a dead rope.

 

One of the biggest factors to be considered with all winching / towing is the attachment point. Particularly as most of the vehicles owned on here are of considerable age and have had some amount of restoration work / welding in the past often of unknown quality.

No-one on here has owned their historic military vehicle from new and knows it's full history.

Edited August 18, 2008 by Stormin
Edited for spelling.

[gritineye]

Stretchy tow ropes of any sort are the most dangerous of all, I have pulled the bumper and dumb irons off an old LR with one and seen a little Susuki recover a bogged RR almost 3 times it's weight with one.

 

The trouble is this type of recovery looks great fun and is spectacular to watch. Due to the dangers this should be discussed at length and discouraged, as winching is the much safer option.

 

I believe (someone may like to comment) the MOD bans KERR recovery on all soft skin vehicles.

[Stormin]

I believe (someone may like to comment) the MOD bans KERR recovery on all soft skin vehicles.

 

A friend of mine was recovering someone at an off-road race event with his ex-military 90 soft top. Two ropes were joined by a shackle, one of which let go! The shackle and rope hit the roof of the 90. The rear flap was rolled up at the time. The flexible rear window was shattered by the impact and the rear hood stick bent. A few inches lower and it would've been the back of his head stopping the shackle.

This was using normal nylon ropes not as stretchy as KERR but still a danger.

 

At another event I saw someone try to recover another stuck competitor with his lightweight Land Rover. The recovering marshall used to store the rope wrapped around his spare wheel whilst attached to a nato hitch. Another Marshall helping the recovery unwound the rope and attached it the stuck competitor. Some off you may have guessed already that the assisting marshall didn't unwind all wraps of the rope. The rear door and a good part of the hard top of the lightweight were destroyed.

[N.O.S.]

That's just the advice I was after, thanks guys. I conclude they are no good for my applications. Pity I hadn't asked before buying, at least they were dirt cheap!

[gritineye]

That's just the advice I was after, thanks guys. I conclude they are no good for my applications. Pity I hadn't asked before buying, at least they were dirt cheap!

 

You could always make some cash with them like this

 

 

http://www.youtube.com/watch?v=O4E2q4B7uug

 

Nowhere near as dangerous as towing :cool2:

[Tony B]

MOD banned Kerr on anything but armoured vehicles eon's ago. Snatch towing is never a good idea you end up with two knackered vehicles for the price of one. Another point, any splice or knot or bend will decrease the rope strength by 20%. Treat ropes with respect, keep clean do not allow to drag in mud and muck, it abrades them. Sunlight and wet are not the freiends of natural fibres. Best answer that I use is a hempen show rope, and a damm great thick Kermantel lay synthetic for towing. ALWAYS use your OWN rope to tow things out, you know where it has been. Keep a few shackles about. Learn at least the Bowline, Timber hitch and Sheet bend and riggers knot to lash things down. These will do 90% of jobs.

Catweazle ! Where are you mate! you should know the value of good line.

[Richard Farrant]

Not sure whether this point has been made so far, regarding KERR ropes. They have a very limited life, the army procedures are to inspect it after every recovery operation, and on the regular equipment inspections. Due to the heat generated on a pull, the strands can fuse together, if this occurs, they should be scrapped. It is quite possible that some of these ropes that come on the market as used surplus, are failed ropes. The test is to lift the strands away from the rope, but if fused to the next one, scrap it!

[Marmite!!]

I'll post this here save keep going to the other thread...

 

 

& the Kerr Data Sheet...

[gritineye]

Richard, it's interesting you mention heat generated on a pull, re my earlier post!

[AndyFowler]

You could always make some cash with them like this

 

 

http://www.youtube.com/watch?v=O4E2q4B7uug

 

Nowhere near as dangerous as towing :cool2:

 

Wow thats insane ! :bow::bow:

[Tony B]

Oh sod that ! the peak G's must be enormous.

[Degsy]

Richard, it's interesting you mention heat generated on a pull, re my earlier post!

 

 

Two unrelated issues, the heat in a Kerr rope is caused by the friction when the rope stretches and then returns to its original length , terrific energy is involved some of which will manifest itself as heat. this does not occur when winching, any stretch in the winch wire would be very minimal and rhere is only very minimal friction as long as the winching is done correctly. Nobody should be involved in recovery of any type without suitable training and experience.

[Tony B]

Unfortunatley electric winches have become quite cheap. They seem to becoming a fashion acessory like the Camel Land Rover round here. Absolutley spotless with polished wheel nuts. I always make a point of being freindly and giving him a wave from my tatty scratched muddy worked ones. :cool2:

[gritineye]

Hear what you say Degsy, just trying to work out what the guy who told me the story actually saw, maybe some other strange effect, like the plasma ball that I saw hovering by the 3 phase power lines beside my house in the '87 storm.

[Degsy]

Rust?

[Tony B]

Or maybe the bottom of something 70% proof? If a wet rope slips on a capstan you can get steam.

[Richard Farrant]

Hear what you say Degsy, just trying to work out what the guy who told me the story actually saw, maybe some other strange effect,

 

 

Of course it could just have been the red painted section of rope to warn you to stop paying out, last few turns on the drum :-D