Recovery Gear Ratings

[dfgeorge]

Just fitted a 12000lb (5500kg) winch and have started looking at the rest of my recovery gear, and what it sould be rated to to use safely. Im starting to confuse myself as to what is safe.

My bow shackels are rated between 3.2T and 4.7T.

Looking at winch extension straps, a lot of them are rated arround 4500kg (some say recovery load, others say braking strain, I assume the recovery load ones are stronger).

If I use a snatch block I assume I will get twice the winch force on the other side of the block. (snatch block is ratted to 8000Kg).

My tree protector is rated at 6,500kg.

Can I safely use my gear with the new winch or do I need to change it all?

What strength winch extension strap can I use safely?

Dave

 

[gunning1987]

youll need all new gear mate, sorry. Id be looking to speak to someone at a rigger shop or a crane shop.

 

[Geoff3DMN]

I've been using 3.2 tonne bow shackles on the front of my Nav but I use a load sharing strap so the force is shared between 2 separate shackles, that might be worth considering.

I've recently upgraded from a hand winch (1600kg) to a 12000lb bar winch and I was concerned that it wouldn't be strong enough if used with a snatch block. For straight pulls it should be ok but I had the same concern as you if it was used with a snatch block.

My tree trunk protector was also only 8000kg.

I ended up buying a Tigerz11 recovery kit which was cheaper than buying all the bits separately and now I've got gear which is rated strong enough for the new winch.

http://tigerz11.com.au/products/RECOVERY-KIT-TESTED-.html

They seem to be having a run on them as a couple of the bits I got in mine are listed as out of stock but they've dropped the price to reflect that so it's not all bad news.

 

[scooba_285]

whats wrong with an 8000kg tree trunk protector? seems plenty strong enough, its not like hes snatching off the tree lol even then the most common snatch strap used is 8000kg isnt it?? i think all your gear is fine to use

 

[Geoff3DMN]

whats wrong with an 8000kg tree trunk protector? seems plenty strong enough

A 5500kg winch used with a snatch block can generate (assuming it can pull at 5500kg) 11000kg of force on the tree trunk protector.

Assuming one never used a snatch block then the 8000kg tree trunk protector would be within it's rating and wouldn't need to be replaced.

 

[scooba_285]

ahhhh i see, i thought a snatch block doubles the pulling power and not the pulling force on that end of the cables / straps etc

 

[Geoff3DMN]

ahhhh i see, i thought a snatch block doubles the pulling power and not the pulling force on that end of the cables / straps etc

The snatch block does halve the force acting on the winch motor because the force is split between 2 lines, so one half (attached to a front recovery point normally) has half the force and the winch has the other half.

However all of that force (both halves) are acting on the snatch block and on the tree trunk protector attached to it.

 

[Old.Tony]

I think the gear is fine. Getting larger items - bow shackles etc - just means you won't be going near their tolerances.

Consider WHAT you are winching. You might have a 12,000lb (that's 5,300kg) winch, but your car - fully laden - is only 3000kg. The only way you'll put - for a long period of time - the full 3,000kg onto the winch (and the cables, straps and shackles) is if you are hanging the Navara off in space.

A flat pull out of a bog will require a fair strain to get the old girl moving, but once it's on the move you are NOT putting 3,000kg of strain on the gear. It is substantially less, even up an incline.

Now, when you are choosing new components, the one thing to remember is that recovery gear works just like a chain - the weakest point is where it will break. If your weakest point is rated above the maximum weight of the vehicle (and you know that you will only exceed that for short periods which the components will probably survive) then your gear - if kept in good condition - is going to be fine.

I guess the amount of excess needs to be considered. A 3T car bogged to the floor in cloying, clinging mud is going to take a hell of a lot to get it out, and it's something that you may want to get advice from someone very experienced in these sorts of things. I can only really provide an engineering perspective on it.

 

[scooba_285]

very helpful info there tony, cheers

 

[terryc]

Actually, I was wondering sort of the same think with all this gear rated to various loads.

This inevitable lead to the question of where is the fuse in the whole system?
i.e. what do you have that will break before your start tearing your Nav apart?

I decided on the 3.2t bow shackle at the front of the equaliser strap.

 

[Old.Tony]

I might suggest that if you want it to break at that specific point, then immediately beyond that point is the ideal place to put dampener blankets.

 

[Geoff3DMN]

A 3T car bogged to the floor in cloying, clinging mud is going to take a hell of a lot to get it out

I once watched a bogged Patrol burn out his winch trying to winch himself out of a muddy bog hole after they'd failed several times trying to snatch him out out.

His mate in a cruiser eventually pulled him out using a snatch block but the winch on the Toyota bent the Patrols recovery points (or possibly the point where they mounted to the chassis).

The way everything was creaking and groaning and making funny noises made me back up a fair way and watch from well back.

So yeah I guess it's possible everything was within spec... but it sure didn't feel that way, didn't feel safe at all in fact (which was why I moved back).

I guess what I took away from that was a healthy respect for the forces involved when winching and a desire to minimize any possible risks.

If that's left me choosing to use gear within it's rated specs as far as possible then that's ok... there are worse outcomes

 

[dfgeorge]

The way everything was creaking and groaning and making funny noises made me back up a fair way and watch from well back.

So yeah I guess it's possible everything was within spec... but it sure didn't feel that way, didn't feel safe at all in fact (which was why I moved back).

I guess what I took away from that was a healthy respect for the forces involved when winching and a desire to minimize any possible risks.

Thats what worries me, there is a lot of energy with the potential to do a lot of harm if something lets go. Im not sure im keen to put a weak link in as it could kill someone if it lets go.

 

[jamie1987]

I have been working with recovery gear for 7 years, if a bow shackel says 3.5 Ton, then that is its safy work load, and the recovery load is double that. ( So a 3.5 Ton SFL, will take 7 Ton pull on it)

As for useing a block, the pulling power then doubles. ( The amount weight on one line is the same on the other line)

When useing a strap, the recovery load is the max you can take it to. Unless you double it around.

When using your winch to pull your 4WD out of the mud, you only pull the max load at the very start, when you break the sucktion the it drops to half the wieght of the vehicle. Sand is just half the wieght of the vehicle.

Hope this helps.

 

[joshman]

As a general rule a try to buy recovery gear that is rated to AT LEAST double what my vehicle will ever weigh. Obviously that's. It always possible, but the closest I can get to that figure, or even exceed it, the better off I'll be.

 

[terryc]

Thats what worries me, there is a lot of energy with the potential to do a lot of harm if something lets go. Im not sure im keen to put a weak link in as it could kill someone if it lets go.

Isn't that what the sand bags are for?

 

[4 naving]

Straps are rated breaking strain for pulling. shackels are rated for lifting, which is a totaly different standard. a 3.2 rated shackle would take 3 to 4 times this load to break it. lifting standards have a lot of saftey margin built in.

 

[Old.Tony]

Thats what worries me, there is a lot of energy with the potential to do a lot of harm if something lets go. Im not sure im keen to put a weak link in as it could kill someone if it lets go.

The obvious - and not always used remedy to this - is a device called a "recovery cable dampener".

A large blanket works just as well. The dampeners you can buy from 4WD places are just large vinyl sheets that drape over the cable with some small weight in the bottom edge to keep them fairly straight. If the cable breaks, the idea is that the cable tries to pull the dampener through the air and, being rather akin to a sail, the dampener slows the cable down dramatically, removing a lot of the force - hopefully enough to prevent major injury or damage.

I could list some really dumb things to do with recovery gear, which might be amusing.

* Don't offer to hold the winch cable so you can feel just how tight it is as the car is being pulled out of the bog.

* Don't offer to hold the cable dampener in place on an incline - that's what gaffer tape is for.

* Don't stand in front of the vehicle being recovered so that you can give clear hand-signals to the guy behind the wheel.

* Don't offer the services of your towball as a mounting point for the hook off your mate's winch (or worse, snatch strap) unless he likes the idea of a "3.5T" stamp in his forehead.

* Your tie-down point is far more suited to tying the vehicle down than it is in recovering your or other vehicles.

* Alloy bars are absolutely, permanently, forever and ever amen, unsuitable for snatching from.

* Don't snatch a vehicle sideways unless you want to drive a banana.

* Don't add a 5th occy-strap to the end of the snatch cable hoping that it'll be long enough now.

I'm sure YouTube has a swag of better examples of what NOT to do.

 

[Geoff3DMN]

The obvious - and not always used remedy to this - is a device called a "recovery cable dampener".

If I can play OH&S advocate for a minute...

Methodology would suggest that cable dampeners aren't really a 'remedy' they are a 'engineering control' which is only one step up the scale from PPE (like the gloves people should wear when handling winch cables).

'Isolation' (standing well back!) would be a better approach.

'Substitution' (using synthetic rope instead of cable) has the potential to significantly reduce the impact force potentially reducing injury in a worst case scenario.

'Elimination' (don't get bogged in the first place) is probably the best option ;-)

 

[FatBoy89]

I love that!!! ^^^^