4WD recovery: How dangerous is drag chain? | Auto Expert John Cadogan
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I’m a digger operator running a 36t exc.
the amount of times I’ve had to say “no” to things is ridiculous.
There is no second chances and every safety rule is written in blood- the blood of our brothers
I work in heavy salvage and whilst we use excavators from time to time my boss has a saying. Excavators are for digging.
Seems pretty silly but when we are dealing with these sort of incidents daily it's helpful to remember that that machine was not technically designed to do that despite its capability
Most excavators I have worked were set up for rockhammer
work and had substantial screens over the windows.
Still wouldn't want to be having a chain heading towards me
at 300+ kph!
@@ivanolsen8596 mines straight glass 😅 I’ve had it smashed by a 10mm pebble lol
Most excavator/digger recoveries I've seen are bucket interlocking not chains and usually similar size machines. Or they use some seriously large and short cables.
@@boomerau depends if you're able to get another machine that close or not.
If you use appropriately rated chain it's not an issue anyway
The army trains people in recovery. They are called "Recovery Engineers"
I listened to two of them comment on footage of untrained people recovering average size 4wd's. It was not complimentary. The advice you give makes sense. Sense is quite often the first thing to be sacrificed.
Share?
To be fair seeing recce mechs operate outside of the limits of the military I too was uncomplimentary 😂
Many years ago, an excavator digging on a beach got bogged down. Daily they would move off the site before the tide came in, but that day, they apparently thought, "just a few more minutes". It was initially comedic, seeing them attach progressively larger pull vehicles, to no avail, and eventually had three other pieces of heavy machinery all pulling together. The sea came in, and the excavator almost disappeared. Just a few miles along the coast is an army bridging and recovery site. After three days of digging and tugging, with the excavator disappearing at each high tide, they eventually called the army. It took the army less than 2 hours to drag it out.
For me, point 1 is, be a wimp, and don't get into such situations, and point 2, swallow pride and call the professionals.
We are called recovery mechanics( recy mech) Safety is of the utmost importance in our job as the forces involved are massive. I can set up over a 100t of winch capacity with my truck. When we plan jobs all our tackle is rated higher then winch cut out so nothing 'should' ever fail. We draw a plan of the entire job and calculate the force on every piece of equipment and anchor point.
I realize this is an extreme use case but here is my experience. Many years ago I was pulling some logs with a1/2" chain using a D7. The chains were unhooked and I accidentally reversed over the chain. One end was fixed to the ripper tynes and the other went under the track. When the chain broke it sounded like an explosion and subsequently flung back and hit the ROPS cab steel mesh with sufficient force to dent it. I have no doubt it would have taken my head off without the cage. Regardless of how you are using towing equipment, be careful and try to stay out of the way.
At 28,600 kg a D7 has the potential to create a very dangerous amount of energy in the circumstances that you've described.
Whereas a couple of Patrols weighing in at less than 3,000kgs each, could never have enough energy to produce such a result.
@@barrynoble68 I agree with you about the Patrols. I was making the point that I avoided injury due to a relatively heavy duty cage and that you should always exercise caution when using towing equipment. Chains are not without danger. As John suggests, providing the equipment is rated for more than the weight of the vehicle and used sensibly, you should be safe. 🤞
@@barrynoble68 The important part of this story is that the chain was attached to the ripper tyne which is a relatively low point on the dozer. An unforeseen mixup with the track meant that when it failed, the chain recoiled and hit the ROPS cage. In hindsight the breaking can be explained so that’s not the surprising part of the story, BUT the really intriguing part is that from such a low connection point it was able to be redirected to impact the ROPS cage.
Every construction worker makes a dozen or more stupid mistakes every day they work. Many of those annoying “government” rules we follow save us probably 20 times every day. 10 for our own stupidity and another 10 for other’s stupidity.
The first instant of chain breaking you mentioned the chain was attached to the excavator backhoe arm, the elastic force involved was most likely more in the arms of the machine than the chain, and most likely the machine was tipped on its tracks if the quick clamp had been raised to the point it was in line with the cab so when the chain broke the machine dropped back to the ground. I have seen several instances where excavators are pulling themselves over to some extent before some thing gives and they land back flat on the tracks.
And that's what I'd be worried about in 4x4s. Sure, very unlikely to snap. But there is likely to be a noticeable shift of the mass of the tow 4x4 when it snaps. Even a small recoil action on a 2 tonn truck is going to have noticeable affect on the momentum of a sub 100kg chain.
I grew up on a Farm/ ranch in the US Midwest. We used nothing but grade 8 chain in different sizes and length for everything we did. We COULD regularly develop over 8 tons of pulling force , lifting force and jerk force all of the time.
We had very large tractors, combines , AG equipment and Semis to haul stuff.
We had to get things unstuck that were buried in mud or drag broken down equipment up onto trailers or lifted up into the air to repair things.
Our own home shop had a 10 ton swinging beam and trolley for lifting and splitting tractors.
We also used a lot of heavy cables and slings. Let's just say we tested things to failure once in awhile.
The break strength on the chains we used were mostly 4 times the rated working load.
I managed to break a couple while trying to recover a large tractor or Semi and full load behind it on a trailer.
What I experienced is exactly what you were trying to tell people.
When the chain popped it was mostly near the middle where it had been worn or near one end or the other where it had been worn by hooking it to itself in the past many times.
In almost every situation we had something draped over it using the 2/3rds rule and it just fell to the ground.
The 2/3rds rule is going to the middle of the chain length and then half way between the center and each end you lay a coat, bag, inner tube or something over the chain.
Sometimes we had smaller old implement or atv tires that we ran the chain through and left at the points near 2/3rds.
We NEVER used a steel cable for that purpose unless it was on a winch with a constant pull and a known load.
When we broke a cab window on a combine is when we tried one of the newer heavy snatch ropes that they came out with. It was like a rubber band even with a coat laid over it. We were nowhere near the claimed capacity of the recovery rope.
We went back to chain with a known capacity and physics.
Well I have winched more cars that I can remember with an 8 millimetre chain.
Out of some horrible bogs and up some very nasty steep embankments.
I've got to say, you're more likely to pull the attachment point out of the car than break that chain.
I use a 20,000lb hydraulic winch, and if that bogs down, you can slide in the tilt tray for some extra mumbo.
At the VERY Minimum you should never be using anything smaller then 13mm grade 80 chain with that winch. Any piece of tackle connected to a winch MUST be stronger then winch cut out. How can civilian tow truck operators not know the very Basics of recovery and winch operation
Thank you John for putting so much effort into your videos. Good job mate👍
So, if I've learned anything from this episode it's probably that the most important thing to ask myself is "are the people I am learning from on 4WD trips actually giving me good advice and setting a good example, or are we just lucky that no-one has got hurt?"
Hi John, just a quick note to inform you that I cleaned up my 5 metre chain and dragged out a 4WD only 2 weeks later easy as piss. Now it's only a 3 Tonne rated chain but worked a dream, happy I clean it up and saved a family from waiting 2 hours for Forrest Dept and yes it's a lashing chain.
We need to teach people to read the directions, too many are already know all's, and can't be told, as an ex recovery mechanic in the army I listen to some people and just shake my head in amazement
As a current recy mech I feel your pain.
Excellent advice for both beginners and seasoned 4 x 4 wheelers! Thank you John, always a pleasure to listen to your 4 x 4 offroad advice!
Facts not BS, good work John as always.
Totally agree with you John have pulled triple road trains bogged to the balls loaded with cattle with a 13mm chain with a dozer but very gently
Yep, have pulled a double out of the dirt with another road train with a load chain. Also used them to pull start truck a few times no worries.
Yep pulled loaded tippers bogged down to the axles but also have broken chains. We always used great caution and never ever let anyone within 20m of the connection points.
@@KWUnt Yeah I have broken them too, they always drop, come back a bit but not much, just stay away. dozers can break chain.
I'll be checking the ratings of the chains we use to recover our bogged firetrucks. Thank you for going to the trouble of making this video, John.
13mm grade 80 chain would probably be then minimum required. 16mm would be better but is heavy and hard to man handle around.
Another brilliant episode, thanks John.
Very informative, loved it John. I could also hear your understandable frustration coming through at times, as it should.
Keep up the great work.
John your spot on mate well put together video
Duuuude, love your show. Intelligent, informative, and your humor is top shelf😄❗️
Thanks for educating me on chains. Very informative!
I think in the first case the recoil of the chain most probably caused by the hydraulics of the excavator arm, when the chain snapped the arm under thousands of psi of hydraulic pressure would have snapped back yanking the chain.
For the poly pipe fatality, I would guess old mate that tied the chain to it was holding the chain in place while the excavator took up the slack.
Then excavator went for it while the guy was still in striking distance.
As a Farmer...(Explains Lack of Caring) Break chains all the time (3/8 10mm). They just fall in the ground and may not even recoil.
Use 2 6t+ tractors pulling bogged B-Double trucks.
A 4WD could never exert enough force to break a 8mm chain.
I carry a certified rated 10mm Herc Alloy drag chain in my truck. I have used it on dozers and tractors here on my property west of Gamala NSW.
It's all about going nice and slow.
Thank you John for the videos, i learned a lot
Thank you, John, for another straight to the point article. I hope that it saves lives.
Sobering and educational. Thanks again, John.
Thank you John, for the fact based reporting, I use 70 grade 1/2 inch ( mostly behind the tractor) 5 tonne working and 3 tonne pulling works out ok. Not to mention 10 meters of that chain is a much as I want to carry.
Now to my question; tow balls as attachment points, I have seen many pundits prophesying doom (DOOM I SAY) if you do this and I have followed links on their websites that purport to back this up, but the incidents so linked never seem to support the hypothesis i.e the receiver hitch was modified/damaged, an unusual drop hitch failed etc.
I think you may have briefly mentioned this in a past video, interested in your comments.
John, these tutorials are great. I would love to see a video on calculation of required effort to de bog a vehicle dependant on how bogged a vehicle is, slopes, bogging in sand vs mud etc. My time in the Army had some very complex calculations used to consider equipment selection based on all of these variables. I find Civvies in general are oblivious to what needs to be considered.
Watching civi do recovery blows my mind. They have no idea. Even the so called professionals have no idea what they are doing. I don't think I have ever seen one use steadying tackle to catch a roll. They just let it flip back on its wheels and hope it doesn't go over the other way
Thanks John, you have fully vindicated my decision to purchase a drag chain over a snatch strap for recoveries. I will say I purchased my chain some time ago but this video truly explains the forces placed on a recovery in terms even my high school physics understood. To me the idea of a recovery device that in itself transfers energy rather than stores it makes a lot more sense for those difficult recoveries. Not only that drag chain can also be used for pulling logs off a track.... Thank you once again for your excellent videos that I watch a lot of......
I enjoyed this lesson. Thanks!
Thank you John. Very informative. I don't 4x4 but a good listen.
Great video C
Very well explained sir
Love it John. As an engineer, you're talking my language at last. Nothing about which rust bucket is better than another!
Always better to go overspec with respect to towing/winching. 'Just Enough' is NEVER enough.
10:00 20 seconds of gold
Top video John
Consider those chains are used in "Frame Straightening" body-shops...whereby a body-on-frame vehicle is "re-bent" to exacting dimensions , these chains are the strongest parts among the string of failure possibilities. By far the majority of failures is using chains as a "snatch "device, identical to straps in usage...they are never to be used as such...These chains with those applied snatch forces will seek out an elastic component, bending frames, bumpers & often times ripping apart unibody structures, detaching entire structures violently.
No doubt about it John, this type of video has become your strength. Science based thinking translated into advice that can be practically applied. Engineers work with this sort of thing every day, but rarely do they have the motive, means, opportunity or resources to communicate it to others effectively. Your videos have/will save many from embarrassment, injury, litigation, a lifetime of misery or death. And they are entertaining to boot.
You comment needs to be pinned. You've mirrored my sentiments exactly. Well done John, you're doing God's work.
thank you very much for an excellent informative session. very well true, much appreciated.
Link ... in the description.
I've seen the recovery of a daihatsu feroza similar to the sinario you mentioned in jest. They used a chain not much longer than the one you've used here, one end was attached with a shackle the other a padlock. Fortunately due to the short length it only made it as far as the back seats, after it smashed through the back window. They were very lucky no one was injured.
Well presented,
I use high tensile short link chain to recover my bogged equipment on my farm all the time. My biggest tractor is 12tn gross. Have never broken one in 45 yrs!
Excellent again mate 🤩🤩🤩🤩🤩👍🏻
I remember working under high voltage tension lines clearing trees, I mean over 300,000 volts. The main supervisor got passed off about the progress of the works and got stuck into a tree near the high voltage lines without any ground rope support. His fancy saw got stuck in a tree, I decided to run for my life along with several of my colleagues, a subcontractor ran to assist him to strike a wedge into the tree and no one died that day. I don't regret making myself safe for foolish behaviour.
Good information, and hopefully will open a few eyes to the potential hazards and hazard reduction in whatever chosen recovery method is being used…
I think the biggest point, which is normally the first step that is missed, is to take a few minutes to assess exactly what is going on before blindly attaching chains/slings/shackles etc.
the other point that people may or may not be aware of, is the difference between safe working loads, and guaranteed breaking strain. The guaranteed breaking strain is the minimum the equipment can take before “breaking”, and the safe work load is this figure divided by the safety factor.
This allows for unintentional shock loading of the component when loaded to the maximum SWL, without the component failing.
Hence why OHS have a field day when investigating failures of 4.7 tonne shackles..
This is the biggest problem with all the shitty 4x4 recovery gear. It doesn't have a recovery load limit. It's all labelled as breaking strain so there is no safety factor. RLL is the same as lashing capacity. It should have a 2 X safety factor
It sounded to me like the chain on the excavator doing the recovery was attached to the quick hitch, and I imagine the boom was raised in the air with the stick vertical. If this was the case, I would expect that most of the stored energy was in in the boom and stick pulling on the chain.
I appreciate the explanations given, cheers
Thanks for this vid John, some good advice in the sea of bad/bias advice that is 4WD recovery equipment.
Have you thought about doing a similar video on using chains for winching?
I wince every time I see a video where some goose is doing a straight line pull on a vehicle stuck so bad that it breaks the winch rope. Resetting with snatch blocks and the like always seems to be off the table for this lot.
These days if you don't have a soft shackle, you are not part of the crew, but sometimes you just can't beat old techniques.
One tip I was given by a retired recovery operator, was to cut the top off an old 5lltr oil container, preferably one where you could leave the handle intact and store your chain in that. Oily atmosphere helps prevent rusting if not a protected chain.
thankyou mate for this one well said dood
A few years back I encountered a couple of young lads stuck to their 4x4 chassis rails in mud. They had ventured off the bitumen down a track and 15m in their progress stopped. No chains, just a couple of lengths of 500kg 12mm (1/2in) rope, and we gave it a try. Gentle on the throttle, automatic transmission in my 4x4, just built up sum tension and let the mud squeeze out of the way. The lads were free and back on hard ground in under 10 minutes....
Do people still regard a 4WD recovery as a "let's crowd around and watch" type of activity? That's what it was like when I was a member of my local South Coast Western Australia 4WD club in 1985. I was only 27, and had recently bought my 1st 4WD (1984 Range Rover). Another vehicle got bogged in a muddy hole, and I offered to do the ballistic recovery using a snatch strap. I'd never done it before. 30 seconds of instruction (floor it in 2 low), and we were off. About 20 people within swinging distance of the strap ( although it was really only dangerous to me and the stuck driver I guess). My 2yr old son sitting in the passenger's seat next to me-no seat belt of course. Snatch strap pulls tight, my vehicle slows down rapidly, bogged vehicle comes free. My son continues forward and puts a huge star fracture in the windscreen with his head! (Windscreens aren't that tough when you whack them from the inside).
No critical inspection of the recovery points of either vehicle. Luckily, they remained intact.
My son was OK. My wife (ex now), was having kittens watching her son headbutt the windscreen! Fun day in Albany!
Chains used correctly will always be safer than straps
From knowledge acquired from experience, and some knowledge of physics, I would add a couple of "points to note"as you try to extract your stuck vehicle. Dragging a vehicle 1 on 1, then all the above is exactly as stated, and a great review. When that didn't work, and you escalate, you can end up trying multiple linked vehicles attached to 1 stuck vehicle. In that case, stand far (really far) away when you pull, whatever you are using, stuff breaks, and you won't get any warning, it travels surprisingly far and extremely fast. My personal preference, after many events, ended up being a snatch strap, my personal choice being a 20 ton snatch strap, which was overkill in spades, but heaps of headroom was a good thing. From trial and error, always seemed to work better if you could soak it in water (i.e. river) first. What was learned, snatch straps do fail, but they tend to fail gracefully, you get more visible pre warning ahead of the failure, like frayed strands. They usually tear and split before they fail catastrophically. Another point often overlooked, attach the snatch strap to a strong part of the chassis, of both vehicles. If you attach to the front/rear bumper of your Subaru/Kia/Hyundai or similar 4wd and pull, you will probably just rescue the bumper, and btw, bumper detachment, can be an instant catastrophic fail where you do not want to be anywhere the now high speed airborne bumper or fog lights etc.
Thanks for that John, the first thing 4x4 shows put on here are snatched recoveries. Can’t say I’ve seen a drag once.
A shovel is the cheapest and most important piece of recovery gear you could have with the exception of some common sense and a coffee or tea while you think about the problem before acting on it.
What ? Think first ? You've got to be joking.... Safety's for the city people.... LOL.
So, my father inlaw had it in his head years ago that he could use a 1/2" diameter rusted cable to loop around a tree that he had cut, but did not tip over, instead it just fell off the stump and leaned up on the next couple of trees. He then told me to put it around the tree and then he put the other end on his trailer hitch. Then his F350 in 4 wheel drive he proceeds to back up to the tree with me taking up the slack to 1 side. We me then running as fast as I could the opposite direction, he proceeds to go full throttle and leap the truck to the end of the cable. So cable did not break. Instead he ripped the entire trailer hitch off of his truck and it flew all the way back to the tree. I told him, it wont work. An I got way out of the way before he tried this maneuver destined for failure. Still have a vision of a bumper sized boomerang flying through the air and a bent rear truck frame twisted and torn like tin foil. Tree never moved.
Years ago it was somewhat common to run a chain through a steel pipe when towing and recovering vehicles. Only the last foot or so of chain was outside of the pipe, with the idea that a failure at any point in the system would limit the exposure to flying steel.
We've had a breakage pulling out a very heavy machine from a bog (shackle broke) and the chain just flopped to the ground and recoiled back perhaps 1 foot. Basically harmless.
From all the videos I watched And recoveries i've helped with. I have come to the conclusion. that if a chain Or snatch strap or kinetic rope Or toe strap Or bow shackle Or soft shackle or cable Or synthetic rope exedra. is undersized Or damaged Or People are using the wrong equipment for the type of recovery They are doing. Things can And will go wrong.
Knowing what sort of recoveries One should use kinetic gear versus static gear on. Also doing everything possible To limit the amount of strain put on your gear. Like you were saying dig out As much as possible. Jack up the vehicle and put things under the tires. To fill in the holds that you've created. Knowing when to stop spinning your tires and digging yourself into a hole And just get the gear out and recover yourself. taking the time to assess the situation. Properly installing the right Gear for the task. Making sure everything is secure. Adding in safe precautions. Starting off Slow and easy. If using kinetic gear Never put a bunch of slack in the line before pulling. never exceed five miles an hour. knowing when to stop and re assessed the situation. Knowing when to call in somebody who has more knowledge.
It's worth noting that using the boom of an excavator has an awful lot of spring in it under high loads, and there is additional spring in the expansion of hydraulic lines headed to each loaded joint
chaining undercarriage to undercarriage would not only work better for an excavator recovery, but it eliminates most of the elastic potential from the equation.
Touch’e well said very sensible advice from one who has seen a young girl nearly cut in half 30 years ago with a flying bull bar attached to a snatch strap and an imbicile driving a Toyota landcriser trying to get a light f30 Daihatsu bogged at double island point blow…. Very sad totally preventable tragedy…
I have used both chains and kinetic straps and I prefer the chain. The application of energy is far more controlled, and slow enough that the pull can be stopped and reset if needed. All that aside, the biggest reason for me is that the chain is washable and inspectable. Try cleaning a kinetic strap after getting dunked in mud soup. You can't get the grit out of the fibers.
I have seen videos of people tearing parts of vehicles trying to use a chain like a snatch strap (high acceleration before the chain is loaded) and there's crap all movement of the chain after the vehicle breaks
THE biggest problem in 4wd recocery systems, is many people DO NOT even come close understanding the physics.
In the same vein, many people have a lot of difficulty dealing with the various ratings and safety factors and if those safety factors exist.
In both the reports referenced, it was not the chain that was responsible for the majority of the recoil energy, in the case of the excavator being towed, the hydraulics would have provided the elastic energy, in the pipeline situation it was the plastic pipe.
There is an issue with excavator operators, that because, that is what they do all day, they tend to want to do everything with the arm.
It would have been much safer on both situations to have connected to the towing pin on the undercarriage.
Which would have placed the engine between the operator and the danger, lowered the towing rig and limited the tension in the rig.
A VERY BIG issue is the mixing of hard and soft materials in the recovery system ......... IF there are soft elastic components in the system they have the potential to propel hard components at great speed. THIS is why we should not join straps with shackles.
IN recovery failures, a very common, I would go as far as to the THE most common failure IS ........ the attachment point.
As A Final point, pretty much all ( commercial and regulated) heavy duty recovery and towing systems ( tow trucks, earth moving transport, army wreckers, tank transporters ect) contain chain.
Because when used properly it is strong hard wearing and the most appropriate material for the job.
Thank you for making this video. It's only a matter of time before people start to realise why the offshore industry only uses rated, certified high tensile chain and steel wire.
All those 4wd's with synthetic winch rope are a ticking time bomb.
Safety is everyone's responsibility.
Safety First, Foremost, Front and Centre.
Methinks, despite whatever experience you do have, you are talking through your hat on this one (possibly outdated info, or worked on an "good old boys' " tender). The most cursory glance at the publicatiopns by a Samson or DSM Dyneema. will put the lie to this. (Similarly some (at least one) "crane people" claim the same thing, ignoring the many (or several) cranes which have converted, or been designed to utilise synthetic rope - with very specific instillation, care/maintenance and operating conditions - Check out Liebherr's data in this if you so desire - lol well I'll be darned, Lankhorst Ropes is even making rated Dyneema slings from recycled plastic).. cheers - generalisations are often incorrect.
- None of these correct users of these modern materials is buying the cheapest garbage from Ali-No-Name.
@@kadmow Norwegian offshore is steel. Thank you for your comment.
Another contentious topic for further development could be: Use of ropes and snatchblocks for vehicle recovery without a winch.
It seems another piece of folklaw that, "winch type rigging" (rope, hooks, closed clevises, snatch blocks and treetrunk protectors, etc) must never be used by vehicles in motion. Force multiplication and sufficient mechanical advantage between the stuckee and the unsticker must surely be safer (and possibly a nice headscratcher/"puzzle to solve" for those engaged in the proper safety assessment, prior to whipping out snatch strap and worn out soft shackle at the first opportunity. (Adequate safety tethering of heavy bits, naturally)
Everybody in a convoy (or more so solo)- should carry adequate gear such as not to be at a total loss the moment things stop progressing... (not to forget: shovel, bottle jack, recovery tracks and random pieces of timber - as well as food, water and warm clothes)
Have had to use chain for recovery a lot in the last year one thing we always do is make the chain as short as possible and keep as much steel as possible between us and the chain and we put waited bags over the center of the chain toslow it down and keep it as low as possible to the ground as we mostly use an escovater to pull out tractors and always use good chains if its not rated and in good condition its not used lives matter
The need for knowledge and experience is obvious.
I won't be using this gear, possibly ever.
Your warnings are well heeded John. 🙏🇦🇺
Are nylon tow ropes as risky as a snatch strap or do they have less elasticity or engineered failure mode.
The point is, if it breaks it can kill you - it doesn't matter if it's a chain, a rope or a snatch strap...
Also a kinetic recovery is always dangerous doesn't matter if you use a chain or a snatch strap - just don't take a run up... and if you feel like you need a run up, change your set up so that you can recover without a run up.
Not a bad video. One thing that would've helped to drive it home is to show a calculation of the energy in the chain V's snatch strap. If the snatch strap stretches ten times the amount of the chain for the same load, it will have ten times the stored energy. Or, more likely, if the snatch strap stretches a thousand times more than the chain for the same load, it will have a thousand times the stored energy.
A good example is a rubber band verses a piece of string. You can stretch the rubber band and flick it a fair distance. If you make a loop of string the identical length of the rubber band, pull it tight to the same force as you would the rubber band, then let it fly... it just falls onto the floor because it has very little stored energy.
And how do u get the stuck vehicle out safely when the recovering vehicle is also on a low traction surface. In my opinion you are always best to use a snach strap that has a much lower breaking strength than the hardware attaching it to either vehicle. That way you have a better chance of recovering the stuck vehicle and if something dose break it will be a strap... best to have a weak link that is not going to kill you..
Love your videos, no manufacture’s marketing BS, thanks. What about soft shackles? Chains and heavy steel shackles weigh a lot and add to the gross weight problem. Are soft shackles a reasonable replacement?
Depends on the situation. They are great for joining straps and piece's of gear with big round edges designed to be used with the soft shackles without damaging them. They are not to good for joining to the car as they can easily be damaged.
I like chain more than strap because it's easy to see how chain is doing. Link is worn or broken... Strap can just sit one year outside and look quite good but sun, rain and ice are gonna bust it and it's gonna look fine except stitching... So you gotta look carefully
Yes!
The main point is the comparison between the potential energy acquired by the strap vs the chain when something on either end gets detached.
In the 1st case it seemed that, given the size of the loads in question, the chain acquired a dangerous level of potential energy, maybe by stretching all the links close to their limit of elasticity. In the 2nd case it was the pipe, as I understood, given its elasticity, that acquired the fatal amount of potential energy.
What would a wise person choose if the tow eye detached when pulling a 2 ton load? A strap or a chain? I would pick the material that stretched the least, in that case, the chain.
On the other hand, if I wanted to build a catapult, then I would use the strap.
Hell there dude! Lets all learn a lesson from this! My work role is WHS and all of this is preventable, every death shouldn't have occurred.
Had an incident when i was a kid when i was a bystander to a car being towed out of a snowy ditch, the carabiner on the tow strap broke and sent a piece flying at some silly rate of speed into the guard rail a few meters from where i was standing, it proceeded to fly off into the woods making a buzzing sound like a bullet out of a movie.
Howdy John as a resident of dingo piss creek I have come on an interesting quandary
I have an older Nissan Patrol fitted with 32 inch tall tires which has left me stranded more than once due to insufficient clearance between the differentials and various obstacles
I am currently investigating whether my best choice would be to fit a winch or to install taller tires as they would both be similar costs
I'm currently leaning towards 33s or a set of 35s but considering that bigger tires and a winch would be the safe bet.
Winch, Taller tires will get you stuck further down the track.
How far does the snatch tow stuff stretch before it breaks, and how far does a drag chain before it breaks? The ratio of stretch would seem to be a guide to the amount of energy stored in it at the time something breaks.
It seems to me that people will make mistakes and when they break it, the snatch strap will contain (guesswork) at least 10 times as much energy as the chain, and that energy could end up throwing a missile at someone.
By the way, I've seen what happens when someone forgets about the slack and snatches a steel wire rope or chain. What usually happens is one if the cars gets badly broken (axle removed in one case, but more often just the towing point ripped off and maybe a few bits bent). I count myself lucky I haven't had to treat a victim of towing stupidity.
In your example of a two tonne ute, would the tractive effort equal two tons? I thought there was a difference between vehicle static weight and rolling resistance/tractive effort? I accept that the stuck vehicle will require additional effort to unstick but would the recovering vehicle be able to exert two tonnes force on the chain? I recall your video about the VW Touareg towing a jumbo jet (I think it was a jumbo). Whilst the plane weighs more than the Touareg wasn't it the rolling resistance that the Touareg had to overcome? Forgive my ignorance, I am no engineer.
It would be less than two tonnes in practice. I'm being generous.
It almost makes sense to introduce weakest links with incrementally stronger redundancies, to alert operators that the job is over a certain load, and can back off. In normal use, even the weakest link would and should never break.
Use chains that are tested and rated for at least 5x the pull you think you require.
I know the breaking strength and WLL of my chain, strap, clevis. I would love to see a destructive testing of a hitch receiver shackle mount. I understand the shear strength of the 5/8th inch pin is high, but I wonder what it is.
I thought that we all would have figured this all out during our misspent youth. It doesn't take a physics degree to know:
The greater the force required on the rubber to pull back a slingshot the further & faster the projectile will fly.
A chain is pretty inelastic & isn't very good in a slingshot, but is excellent at being stuck between 2 lengths of round wood for swinging about ones head to show off to your mates & give self inflicted mild concussions.
It requires more effort than just you and a bunch of mates to brake the chain on a swing in the park.
Applying that knowledge to the problem of recovery & it doesn't take much goatee stroking to figure out that a snatch strap is going to slingshot a projectile at the opposite of the point of failure, a chain is much stronger than a strap & will more likely move in a whipping motion if it fails and we're trying to move a total mass of around 4,000 kg, so it should be done with care & consideration, otherwise a mild concussion would be the least of our problems.
I would love to see your take on the use of kinetic ropes for recovery.
I have one and can say from experience, makes recovery way easier and the kinetic rope makes the sharp snap into a gradual strong pull. With a kinetic you can use a smaller vehicle to pull out a larger vehicle up to a point.
Given they store more energy than any other method of recovery, they are going to be the most dangerous if something ends up flying, such as a tow ball. They do have the advantage of being more gentle, so don't put the same shock load on things, but that counts for nothing if they fail....it's going to recoil incredibly fast.
@@Pete856 If the towball detaches with a kinetic you are going way too fast or the structural integrity on the towball is compromised.
@@modarkthemauler NEVER, EVER attach a snatch to a towball! About half of all deaths in 4wd recovery are from this EXACT scenario.
@@blarglemantheskeptic I have done many recoveries using the towball. Using a kinetic rope I have had no issues whatsoever. But I don't drive like a maniac when pulling someone out so that might have something to do with it.
Summing up, when all the links are stretched close to their elastic limit and one link lets go, that elastic energy is released.
John where do you get your shirts?
Chains aside, whatever you do, make sure you securely fasten the strap or chain to the bumper COVER.
You don't want to fasten it to the bumper itself or (heaven forbid) a tow hook or even the chassis - three's nothing to absorb the shock and you will damage something! Manufacturers put those things there to collect more money from you in the spare parts department.
What is the aprox breaking strain of the Bunnings 8mm chain? That is the one that most travellors to Dingo we we Creek would carry
4:45
It’s not “breaking strain”, it’s “breaking strength” 6:00. You learn that in engineering properties of materials classes. Strain is something else, defined as “change in length divided by original length”. Anyway, it’s important for the lecturer to use accurate terminology lest the students end up being taught nonsense
I'd love to visit dingo piss creek someday.
John all those self proclaimed 4x4 recovery experts out there mush hate you with vengeance plus those shop's that sell all that recovery gear. How dare you undermine them. You only have to watch any 4x4 show on TV or go into any aftermarket 4x4 store and ask for little advice on what you may need to get yourself out of a bogged situation and if you were to take their word a gossip, you would be leaving the store with a bull bar, winch, 2 sets of matrax a bag of snatch straps, soft shackles and maybe a shovel. With NO advice on how to use any of it. You have less chance of damaging your vehicle using a proper rated tow chain in a bogged situation then using a snatch straps, providing a little common sense is used. I have seen recovery points, bull bar ripped off Landcruiser's and the front axel pulled out of a Mack semi with the use of snatch straps.
If I was bogged or some other unlucky person was bogged and for some strange reason all we had left was a chain yes I would definitely use it but to extreme safety cautions it's a no brainer or stay there stucked
A rope off the mid point of the chain or strap off to a tree that is at about 90 degrees is a good way to tame the danger. If something lets go, the odds of anything hitting either vehicle is greatly reduced.
A drag chain ? Is it that time year already ?
30t via the APC on the way to dingo piss creek?
I’ll throw this into the conversation, a snatch strap as a rule should be discarded and replaced every 15-20 uses. Even after less uses if any contact with the ground has occurred. Elasticity has a use by date.
If I got stuck that many times I’d find a new hobby.
average weight of full chassis 4x4 is roughly 2.5 tons off the lot, that is not a tow chain that is tie down chain.. you be running 2x 50 or 2x 100+ ton wire chains, if ya that bogged in a excavator you be using the bucket and something rated to tow out the excavator in the truck
1990a leopard one tank recovery cables by 2 and fun times if the shackle fails hehehehe have images yet none of a failure
Got a mate who lost his leg from the knee down doing an off road recovery. Weirdly he married a girl who’s sister had a husband who had a gimped arm from a similar event. They both came from a rural BC Canada area where that kind of thing happens on rare occasions. 😢
BTW I’m sure the straps and chains used were pure rubbish. I’ve work with excavators for many years and seen hundreds of pulls and lifts and only had one chain break and it was a thinish diameter “gate” chain and it was lifting 4-5 tons and the arm of the excavator curled and broke it, (excavator was a series 250 Hitachi in good condition so extremely powerful). “Goldie” chains NEVER break unless we are talking about tug boats and cargo ships or Diesel Electric trains. Nothing used in civilian situations.