Recovery strap oopsies.

[Patr80l]

https://www.brisbanetimes.com.au/national/queensland/man-killed-by-snapped-towing-strap-as-he-was-helping-bogged-driver-in-central-queensland-20180318-p4z4x1.html

Avoidable?

[Rumpig]

Likely very avoidable...but without knowing what broke and why, it's hard to say really for this situation. Sadly many people think snatch straps are a right pedal to the floor recovery device, but if they deflated their own tyres more and remembered it's a giant elastic band basically that doesn't need speed to work, then many of the deaths or injuries that have happened would have been avoided.

[gronk]

Likely very avoidable...but without knowing what broke and why, it's hard to say really for this situation. Sadly many people think snatch straps are a right pedal to the floor recovery device, but if they deflated their own tyres more and remembered it's a giant elastic band basically that doesn't need speed to work, then many of the deaths or injuries that have happened would have been avoided.

Exactly.....every 2nd snatch you see on video is done at a speed that isn't needed.
95% of recoveries only need a tow, but some seem to think once that strap goes on, a snatch is the go ?

[Pottsy]

Exactly.....every 2nd snatch you see on video is done at a speed that isn't needed.
95% of recoveries only need a tow, but some seem to think once that strap goes on, a snatch is the go ?

Many also fail to use an appropriate dampener in case of breakage.

[Charlie Brown]

Many also fail to use an appropriate dampener in case of breakage.

The recommended safe method is two (2) dampeners.  One at each end, a metre from each attachment point.

[DaveR]

A snatch strap by itself going through a laminated window and keep enough momentum to kill someone.
Really?
I can't help but think something shaped like a letter "D" was on the end of that as well......
What a sad incident for everyone.

[corndog]

Watching a video from RV Daily about snatch straps as I'm reading this. Maybe more people should watch more.

[Pottsy]

The recommended safe method is two (2) dampeners.  One at each end, a metre from each attachment point.

Thanks Charlie Brown, did our 4wd course two years ago and only one dampener was used but I can see the logic in two and the positioning.

[Rumpig]

Watching a video from RV Daily about snatch straps as I'm reading this. Maybe more people should watch more.

i helped make this video below for The Fraser Island Fishing Comp many years ago, it shows how simple prep work and going slow still unbogs a well  stuck fourby (I didn't mean to bury my vehicle that much...lol). What you don't see in the video is the recovery vehicle actually stalled and stopped after it took up the slack of the strap, we couldn't show the Patrol  (owned by the guy these days known as Dingo Dave from Offroad Adventure Show) in the video, as it was a Toyota sponsored event. Speed has nothing to do with making a snatch strap work properly, it just adds danger to the situation.
https://m.youtube.com/watch?v=oISdDPliZSA

[DaveR]

At least you didn't have to play with the shovels Mal.
Great looking spotties...

[Rumpig]

At least you didn't have to play with the shovels Mal.
Great looking spotties...

i didn't sell them to you, saying they've never been offroad did I?...lol

[Charlie Brown]

Thanks Charlie Brown, did our 4wd course two years ago and only one dampener was used but I can see the logic in two and the positioning.

Mate, it is a great credit to you that you did a 4WD course.  Well done.  Most people, read macho males, buy a fourbie, think they know it all, never read instructions or take advice and go off and "learn from their mistakes".  Sometimes those mistakes are fatal.

[Brij]

A snatch strap by itself going through a laminated window and keep enough momentum to kill someone.
Really?
I can't help but think something shaped like a letter "D" was on the end of that as well......
What a sad incident for everyone.

It can happen, although this example is not directly comparable -

A company on the other side of Vic that we share notes with was trying to tow one of their bogged tractors out with another tractor using a very heavy snatch strap. This was their normal recovery process. The eye of the snatch strap broke at the towing tractor end, recoiled back towards the stuck tractor, nicking the top of the radiator and intercooler as it passed through the front top edge of the bonnet, then passed through the front windscreen, somehow missed the driver and lodged in the rear windscreen.

Again, not directly comparable due to a lot heavier strap, but only marginally heavier glass.

We had already moved from snatch recovery to building a purpose built recovery vehicle using 60,000lb winch and snatch block on every recovery. Previously  (and before I joined the company) their most difficult recovery involved a 4 tractors all hooked to one bogged tractor. Scary just thinking about it. All snatch straps have now been destroyed to make sure no one uses them "just one last time".

The other company now also has a purpose built winch truck.

[Ragman]

Use gear in the manner that's been designed for.
as a mate of mine said "if you push it to the limit, don't be surprised when you get there"

regardless if it's a snatch strap shovel or winch!

[trinityalyce]

Always sad reading stories like this. May have been avoidable, perhaps just one of those unfortunate events where everyone did everything right and things still went horribly wrong... we won't know if we weren't there.

Regardless, it's a sobering reminder to make sure we do recoveries as safely as possible. There's a lot of inherent risk regardless of how they're attempted, keeping it minimal is always a good idea.

[Symon]

The recommended safe method is two (2) dampeners.  One at each end, a metre from each attachment point.

People put far too much emphasis on dampers.  On wire rope they make sense, but not on dyneema and certainly not on snatch straps.

Think about how much energy is in a strap when it breaks, what do you think that pissy little bit of canvas is going to do for you?

https://www.youtube.com/watch?v=M0-p_o91f7Y

https://www.youtube.com/watch?v=-3avKbgSfuA

[Pottsy]

People put far too much emphasis on dampers.  On wire rope they make sense, but not on dyneema and certainly not on snatch straps.

Think about how much energy is in a strap when it breaks, what do you think that pissy little bit of canvas is going to do for you?

https://www.youtube.com/watch?v=M0-p_o91f7Y

https://www.youtube.com/watch?
v=-3avKbgSfuA

And if it's not the strap that breaks and it's the shackle, recovery hook or God forbid towball you have a metal projectile travelling at speed. Sorry but I will stick with using a damper.

[Merts]

People put far too much emphasis on dampers.  On wire rope they make sense, but not on dyneema and certainly not on snatch straps.

Think about how much energy is in a strap when it breaks, what do you think that pissy little bit of canvas is going to do for you?

Dampers definitely DO work on snatch straps. They help to direct the broken strap down towards the ground, which stops them from going through windows. They also provide air resistance which decelerates the broken strap and/or anything attached to the end of it (if it has broken the mounting point for example).

[tryagain]

The recommended safe method is two (2) dampeners.  One at each end, a metre from each attachment point.

But if the strap then breaks anywhere in the middle (not as common but certainly not unheard of) then your dampeners will virtually be redundant.

[trinityalyce]

Having a damper with a little bit of weight to it may at least help in majority of circumstances, and is less likely to cause harm. The potential benefit of using one is enough that I'll keep doing it. I do see your point, Symon. There's a heck of a lot of energy in snatch straps under load (really don't feel like doing the calculations on that when my physics is so rusty!  ) but on the off chance a damper could save my life or that of someone else around me, I'll keep using them.

That said, using a damper means next to nothing when you go and attach your giant elastic band to some weak metal projectile-to-be like an unrated shackle or towball...

No recovery is completely safe and routine, and shouldn't be treated like it is.

[Cruiser 105Tvan]

But if the strap then breaks anywhere in the middle (not as common but certainly not unheard of) then your dampeners will virtually be redundant.

Sorry Tryagain, you got a little excited and didn't correct it before posting.  Or at least, I hope that's the case.

[tryagain]

   Sorry Tryagain, you got a little excited and didn't correct it before posting.  Or at least, I hope that's the case.

Thanks fixed. That's what can happen when you don't read what you have written before you hit post.

[GBC]

People put far too much emphasis on dampers.  On wire rope they make sense, but not on dyneema and certainly not on snatch straps.

Think about how much energy is in a strap when it breaks, what do you think that pissy little bit of canvas is going to do for you?

https://www.youtube.com/watch?v=M0-p_o91f7Y

https://www.youtube.com/watch?v=-3avKbgSfuA

Back in to 90's when the Brisbane 4wd show used to held in the park opposite the RBH (getting old ), One 4wd club had a display setup showing exactly how a dampener works on a snatch. They would tension a strap with a winch - through a car bonnet with a hole in the middle (through which the strap went), and firstly let fly with a 2t shackle on the end which would punch straight through the bonnet and leave a mess. Next they did it with a dampener 1/3 in from the shackle end. It worked very well - the dampener 'caught' the snatch strap as the shackle flew past and the whole show would literally drop out of the air every time. The dampener never moved more than about a metre - Air brake is the correct term. You don't need any extra weight in the dampener. As you can imagine I don't think any show organisers these days would get the insurance to put on such a display, but it was certainly a great drawcard. I'll never forget the sound and the damage that shackle caused. You could hear it all over the showground when they let it go.

[Bird]

People put far too much emphasis on dampers.  On wire rope they make sense, but not on dyneema and certainly not on snatch straps.

Think about how much energy is in a strap when it breaks, what do you think that pissy little bit of canvas is going to do for you?

http://www.whyalla4wd.org.au/Shackles.html


Determine Speed of Shackle if Snatch Strap Breaks.

If all the Elastic Energy of the Snatch Strap is transferred to Kinetic Energy in the Shackle then the peak Speed of the Shackle as the Snatch Strap returns to it's 9.0m length can be determined. (Assuming no losses due to friction)

From Energy Conservation,

    Elastic Energy in Snatch Strap = Kinetic Energy of Shackle
    PEStrap = KEShackle
    1/2 k x2 = 1/2 m v2
    where k = spring constant
    x = distance stretched (meters)
    m = mass of shackle (kg)
    v = velocity of shackle (m/s)
    1/2 (20750N/m) (0.579m)2 = 1/2 (0.68kg) v2
    v = 101m/s

    or Peak Speed of Shackle   v = 364 km/h

[tryagain]

Dampers definitely DO work on snatch straps. They help to direct the broken strap down towards the ground, which stops them from going through windows. They also provide air resistance which decelerates the broken strap and/or anything attached to the end of it (if it has broken the mounting point for example).

I think the question though is how much difference they make, if the strap is breaking then there is normally a LOT of force involved, that in proportion to the wind resistance and weight involved in a  Dampener would somewhat dwarf it.

Back in to 90's when the Brisbane 4wd show used to held in the park opposite the RBH (getting old ), One 4wd club had a display setup showing exactly how a dampener works on a snatch. They would tension a strap with a winch - through a car bonnet with a hole in the middle (through which the strap went), and firstly let fly with a 2t shackle on the end which would punch straight through the bonnet and leave a mess. Next they did it with a dampener 1/3 in from the shackle end. It worked very well - the dampener 'caught' the snatch strap as the shackle flew past and the whole show would literally drop out of the air every time. The dampener never moved more than about a metre - Air brake is the correct term. You don't need any extra weight in the dampener. As you can imagine I don't think any show organisers these days would get the insurance to put on such a display, but it was certainly a great drawcard. I'll never forget the sound and the damage that shackle caused. You could hear it all over the showground when they let it go.

It would be interesting to know what percentage of a straps rating they were letting it go at, It would likely be able to punch a hole through a bonnet at a fraction of the force involved when compared to a good straps breaking strain and therefore be much easier to arrest a lesser force with a dampener than it would with the full force involved, from your description the shackle was also actually hitting the dampener which would be reasonably effective but not sure how realistic it would be in the real world with vehicles often at different elevations in a recovery.