Recovery - The Fundamentals [Archive] - NissanPatrol.com.au Forum

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MudRunnerTD

15th December 2010, 11:12 PM

I am a Driver Trainer with my club and last year had to put together an Advanced Course for Winching and Recovery.

Below is some good information that i put into a Course Book for each of the Participants.

I did not write allot of it but compiled it here from a number of places and put it together here. I acknowledge the work of 4WD Action Mag for quite a bit of the detail.

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Advanced Recovery - Tips and Techniques

Basic Recovery Gear

Rated Recovery Points, Snatch Strap, 4.5t “D” Shackle,
Winch, Tree Trunk Protector, Winch Extension Strap,
Snatch Block, Winch Dampener Blanket, Hand Winch,
Gloves,

Not everyone will carry all of this gear, some of it should be carried as personal safety equipment and the rest could be carried amongst the group if you are travelling in a convoy.

Minimum requirement with any Four Wheel Drive vehicle should be a snatch strap and pair of gloves.

Recovery of a Vehicle

Recoveries are a difficult task and should not be attempted lightly. There are risks involved to vehicles and people and all the risks should be considered before any recovery is attempted.

Check list for safety

1. Secure the Vehicle – is the vehicle in danger of sudden movement? Can I Secure it via a tether line for safety?
2. Is there a risk to people? What can I do to reduce the risk?
3. What kind of terrain is it?
a. Is it flat?
b. Is it a bog hole?
c. How deep is the mud that I am in?
d. What is the angle of slope of the hill?
e. What affect will the slope have on the weight of the vehicle?
f. What recovery gear do I have?
g. What is the recovery gear rated too?
h. How many people really need to be involved in this recovery – Can I clear the hill, move people away?
i. Who is in-charge? – There should only be one person in-charge of the recovery.
j. Ask for advice from others, don’t be shy.
4. Can I lighten the load on the recovery equipment?
5. Be willing to think outside the square.

Buying the Right Winch

Remember this. It might save your life or your vehicle.

There are very few, if any, industry standards when it comes to the claims that can be made about winches and load rated gear and vehicle based winching.

Winch Manufacturers can make all sorts of claims about load rating and line speeds and the consumer will have very little if any option but to believe them. This is probably one reason why so many different brands have sprung up over the last few years – Because They Can!

Why Buy a Warn Winch for $1700 when you can buy an Ebay Chinese copy for $400? Please read the last paragraph and think about it hard when you are swinging off that winch cable with your family in the car on 30 degrees next time! Consider a second hand Warn for $800 or don’t go down that track.

If the local hardware store or Ebay seller had to run their winches through the NATA laboratory test or similar to prove all of the claims on the box, perhaps it wouldn’t bother selling it in the first place. This isn’t to say that all Asian winches are a dud, far from it! But can you tell the difference?

There are stories of some of these Asian winches being used heavily in the field and not only passing the test, but thriving. The problem is? Do you know which one? And was it built the same as the one beside it sharing the label?

Given that winching is one of the most dangerous and potentially Lethal 4WD operations you can undertake, you really want to know the risks that you face and whether your equipment is up to the task?

Before you hit the track, the smartest thing to do is to run your loaded vehicle over a weighbridge. This gives you a “Loaded weight” of your fourby and will probably be as much as 1.5 times it bare weight. Of course if you are on a big expedition your vehicle could be as much as twice its bare weight. So obviously this would be really good to work out. You are then making your decisions in relation to recovery with a true indication of weight of your vehicle.

Basic Winching and the Affect of Slope.

Winching on flat ground in a straight line is pretty well as safe as houses as long as you adopt safe work practise. The load is well within the ratings of the equipment on every 4WD. But who does that?

Standing clear, Using a Winch Blanket and connecting to a Rated Recovery Point on the vehicle is all that should be needed to extract the vehicle.

How much are you really pulling up that hill when you are swing off a winch cable on a 30Degree slope? And what about when you are bogged to the axles or sitting on your belly in the mud? Sticky Otways Mud?

What if you have to winch around a corner? How do you do that?

There are basically four different types of resistance that you will encounter while off roading that affect the load on the winch. These include:

1. Surface Resistance.
2. Slope Resistance.
3. Bog Resistance.
4. Damage Resistance.

The figures below come from extensive reading and research and a dash of commonsense. As explained earlier, there is no comprehensive list of regulations for recovery that contain this information.

To move or pull a 4WD on a firm flat bitumen surface requires a force of just 10% of the loaded weight of the vehicle. To do the same on gravel or grass increases this to about 33% of the loaded weight of the vehicle.

Throw an incline in and that maths increases significantly.The percentages need to be added to the loaded weight and can change things dramatically and quickly increase the weight being recovered to far beyond the capacity of the equipment.

For an Incline, or Up Hill, the following extra weight should be added to the loaded weight of you vehicle as a guide:

• 15degree Slope == add +25% of the loaded weight

• 30degree Slope == add +50% of the loaded weight

• 45degree Slope == add +75% of the loaded weight

On flat ground no change is required

For a Decline, or Downhill, the following weight can be deducted from the loaded weight of you vehicle as a guide:

• 15degree Slope == subtract -25% of the loaded weight

• 30degree Slope == subtract -50% of the loaded weight

• 45degree Slope == subtract -75% of the loaded weight

Basic Winching and the Affect of MUD.

But what if your bogged? If your fourby is bogged in the Mud then the depth of the bog will have a massive affect on the loaded weight of the vehicle.

Below is a guide only for calculating the dead weight of the vehicle when in mud.

Bogged to the Base of the Wheel Rim, you will require a pull of 100% of the load

Bogged to the wheel Hub, the weight doubles! You will require a pull of 200% of the load

Bogged to the Belly or the Chassis and it is x3! You will require a pull of 300% of the load

And lets face it, the later is when winches are really being asked for.

Apply these weight variants to ALL of your RECOVERY gear!

Consider these variations when you are looking at your vehicle and considering how you will extract it form its position. Consider being stuck in the mud to the chassis on a 25degree slope!!!

Pounds Vs Kilograms – the Real Story.

Why do we have winches on our vehicles that quote the mass weight strength of the line pull in Imperial Pounds when we are living in a Metric System of Measure.

It because the bench mark brands of winches originate in the USA where it is all about pounds.

And lets face it 8000lbs sounds much tougher than 3600kgs! Imagine the Warn High Mount called the 3.6.

Get to know your gear and get to know it in the Metric world. Do the conversions and document them in your vehicle if you cant remember them. Send it to yourself as a text message on your phone so you never forget. This will save your life.

For the record - 1lb equals 0.454kgs, or 1kg equals 2.2lbs.

8000lbs = 3632kgs
9000lbs = 4086kgs
10,000lbs = 4540kgs
12,000lbs = 5448kgs

Scenario

So, your average GU Patrol for example has a loaded weight of 3.3t (2.2t tare by 1.5t). Your stuck to the chassis, so you will need to pull 9.9t out of the muck (3.3t x 300%)

Throw on a camper trailer (1t) and your Nissan’s winch and recovery gear needs to deal with 12.9t!

Now look at the list above and see the problem you are in!!

Enter the Snatch Block!

An introduction to the Power of the Multi-Line-Pull.

We’ve just worked out that, by itself, your winch is in big trouble. The electric winch has many limitations and is not the be all and end all. By itself it is very handy and will give many an inexperience four-wheel driver a false sense of security and confidence and can get you into more trouble than it can get you out of if in the wrong hands.

This is why we like to use the humble Snatch Block. You cant have too many of these. If every one has one then you may have many on a hill. This is all good.

The snatch block is a rated piece of equipment that allows the cable to run over a pulley and change direction too another tree or back to the winching vehicle.

The awesome power of the Snatch Block is that as soon as you introduce a pulley within the line you HALVE the weight on the line!! Add 2 Snatch Blocks and you reduce the weight to 25% of the line weight at the hook!

Add Three? Well, then you will reduce the load on the winch to 1/8th of the load on the hook. This is called a Triple Line Pull. It is slow but very effective.

Remember, every time you add a Snatch Block you halve the weight, but also halve the speed of the winch but double the power so who cares.

**Very Important.. The mathematics that we have set out here is only true if the pulley is set up to allow the pulley wheel to turn with the cable.

The Weakest Link

**Very Important

Remember that the main reason that we introduce Snatch Blocks is to halve the weight on the winch effectively allowing us to pull far in excess of the pulling power of the winch.

Often when Snatch Blocks are introduced the winch line is used up in the double or Triple line pull and we have to use a Winch Extension Strap. What is the rating of this strap?? The more Line pulls the more likely that you can introduce a weight beyond the breaking strain of the strap. This is very easy to do and it is disastrous.

Massive loads are placed on your recovery system when introducing Snatch Blocks; so think about all of it every time you use it, when ever you pull it out and after you pack it away!

The Final Check List

1. Is your recovery Hook rated and to what level?

2. What is the breaking strain on the Winch Extension Strap?

3. What about the Tree Truck Protector?

4. The Shackle?

5. What does my Winch cable look like?

6. What does it look like now?

7. Did I pack it away and re-spool it properly?

8. Have I lubricated it?

9. Is that winch cable that I will hang off one day just a rusty Birds nest on the front of the vehicle or re-spooled and lubricated ready for use?

10. Have I put any of my gear under extreme load before? And should it be replace?

Rule Number 1

Work Safely, Protect Life.
Determine the load,
Assess the Environment.

THINK!!

Enjoy the drive, Tread lightly

Special thanks to Australian 4WD Action for being a great Resource

Cheers MudRunnerTD
AKA Darren

MudRunnerTD

15th December 2010, 11:34 PM

http://nissanpatrol.com.au/images/SlopevWeightCalculator.png?t=1292414606

81748

MudRunnerTD

15th December 2010, 11:41 PM

I did not want to have this bit lost in the Soup of the above post.

The young fella that died in QLD on the weekend would still be alive if they did the maths and understood the affect of
HOW DEEP THE MUD IS DETERMINES HOW MUCH YOU WEIGH.

If you have a Snatch strap rated at 4,500kgs then by the calculations below you should not even think about pulling it out if your up to the Hub in Mud.

My GQ weighs in at around 2,800kgs. If i was in a Bog hole sitting on my guts i would need a Snatch strap rated at at least 300% of my weight = 2,800kgs X3 = 8,400kgs!! and that is without the slope of the entry or exit out of that bloody Bog hole. Add "affect of slope here">>>

Basic Winching and the Affect of MUD.

But what if your bogged? If your fourby is bogged in the Mud then the depth of the bog will have a massive affect on the loaded weight of the vehicle.

Below is a guide only for calculating the dead weight of the vehicle when in mud.

Bogged to the Base of the Wheel Rim, you will require a pull of 100% of the load

Bogged to the wheel Hub, the weight doubles! You will require a pull of 200% of the load

Bogged to the Belly or the Chassis and it is x3! You will require a pull of 300% of the load

And lets face it, the later is when winches are really being asked for.

Apply these weight variants to ALL of your RECOVERY gear!

Consider these variations when you are looking at your vehicle and considering how you will extract it form its position. Consider being stuck in the mud to the chassis on a 25degree slope!!!

Rule Number 1

Work Safely, Protect Life.
Determine the load,
Assess the Environment.

THINK!!

MudRunnerTD

15th December 2010, 11:57 PM

So in this pic i am up to nearlly my chassis and way over the hubs. I reckon i was 250% over weight.
.This would equal a winch pull of 7000kgs! NOT KIDDING.

http://nissanpatrol.com.au/images/Action%20Pics%204B/n696355935_833615_2514-1.jpg?t=1292415586

HOW ABOUT THIS ONE - 300% = Line pull or snatch of 8,400kgs

http://nissanpatrol.com.au/images/Action%20Pics%204B/n696355935_833616_2808.jpg?t=1292415586

How about this one? Double line pull on an Up spec'd Hi Mount.
SLOPE + DEPTH OF MUD + WEIGHT OF CAR + QUANTITY OF ORGANIC MASS BEING PUSHED OUT IN FRONT

25 Degrees = Load (2,800kgs) + 45% = 4,060kgs X 300% for mud = 12,180kgs
PLUS the wieght of the Organic mass out the front (About 3m3) and we were up around the 15,000kgs!!

Put in a Snatch block and that is halved to 7,500kgs, and what is the Hi Mount rated at? 3,632kgs!
Should have done a triple line pull...Even a Triple Line pull would be 3,250kgs!, near the max capacity of a HiMount.

And it felt every bit of it!!

That is not my car, i took the photo, i was next through that hole though and i did a triple line pull and it was still a very big pull out.

This was the first of about 10 holes just like it that day. You have to be very switched on and get it right or things go wrong.

http://nissanpatrol.com.au/images/Action%20Pics%204B/n696355935_833620_3990.jpg?t=1292415849

http://nissanpatrol.com.au/images/Action%20Pics%204B/n696355935_833624_5194.jpg?t=1292415849

Bigrig

16th December 2010, 12:15 AM

Awesome, Awesome work mate - well done on putting this up!!!! Full marks to you!!!

16th December 2010, 04:29 PM

Great work mate, thanks for taking the time to post this up.

This information is A+++ and I'm sure every single person who read's this has learnt something regardless of your skills.

Well done mate!

Finly Owner

17th December 2010, 12:05 AM

Excellently spelt out. I wasn't aware of all of that.

Is this sticky?

MudRunnerTD

17th December 2010, 12:25 AM

Cheers Guys, please feel free to share it around, a Safe Recovery is an Educated Recovery. Nobody knows Everything.

Cheers Darren

tkn

5th January 2011, 04:51 PM

Without wishing to distract from the very useful MudrunnerTD posts, there are two things I would add -

1. Maintain all recovery equipment in top condition or make out your will.
2. Keep your cool when you get stuck, bogged, etc.

In terms of difficulty, mud is probably the worst recovery situation. Everything slips and slides and gravity is your arch enemy. Sod's Law of Mud Recovery is - "Your capacity to imagine a worse situation is always exceeded by reality."

5th January 2011, 08:56 PM

the evil twin

10th January 2011, 05:41 PM

Firstly, what a great Post Darren,

I am also a Driver Trainer and Rescue Systems Instructor with the S.E.S. which brings a heap of personal satisfaction which I am sure you get as well doing similar with your Club.

If I may be permitted to make an observation in the interests of accuracy tho. The figures for two snatch blocks IE triple line pull are incorrect. A standard triple line pull provides a 3:1 mechanical advantage not 4:1 reduces the load on the cable to 1/3rd not 1/4.

25 Degrees = Load (2,800kgs) + 45% = 4,060kgs X 300% for mud = 12,180kgs
PLUS the wieght of the Organic mass out the front (About 3m3) and we were up around the 15,000kgs!!

Put in a Snatch block and that is halved to 7,500kgs, and what is the Hi Mount rated at? 3,632kgs!
Should have done a triple line pull...Even a Triple Line pull would be 3,250kgs!,

In that example the "triple line pull" cable load will be 1/3rd or 5,000 Kg's hence the "triple" in the M.A. rig name.

Whilst on the subject... There is one other factor in M.A. rigs for everyone to keep in mind as well, the load on the snatch block is the sum of the loads on the cable so again to use the same example whilst the load on the cable is 5,000 Kg's the load on the strap or shackle securing the snatch blocks to the vehicle and tree (or whatever) is 10,000 Kg's.

Here is a cracking good article on M.A. Rigs and loads to illustrate.

Figure 7 Rig C shows a standard or "triple" line pull 3:1 M.A. rig most people are familiar with and utilise (2 Snatch blocks, 3 anchors)

Figure 8 Rig A shows how to get a 4:1 M.A from only 2 Snatch blocks and 3 anchors with the lowest load on the Shackles and Rigging using a compound rig which would indeed reduce the line load to 3,750 KG but is no longer a "triple pull". This method needs another rope or cable tho for the 2nd 2:1. In my case I carry a length of Dyneema for this and other uses.

http://www.ncstaff.net/oed/Pulley%20MA%20Systems.pdf

Again, my compliments on a top shelf amount of info. The more we get the info out there and the simpler it is then the safer it is for everyone and hopefuly the tragedies will diminish

Sir Roofy

10th January 2011, 09:08 PM

You could put a short info night in on the 2012 meet,as an up date on gear and technique

cheers roofy

Bigrig

10th January 2011, 09:11 PM

You could put a short info night in on the 2012 meet,as an up date on gear and technique

cheers roofy

Not a bad idea to have training sessions of some description if we are going to have some qualified lads and ladettes out there ... nothing too over the top/time consuming, but you get the gist ... good call roofy!!

DX grunt

10th January 2011, 09:13 PM

Thanks for bumping this thread.

I've been looking for it for days.

Ross

10th January 2011, 09:41 PM

You could put a short info night in on the 2012 meet,as an up date on gear and technique

cheers roofy

That's a great call Roofy, that would make a good night learning more about the fundamentals and facts for sure.

the evil twin

10th January 2011, 10:21 PM

That's a great call Roofy, that would make a good night learning more about the fundamentals and facts for sure.

It's amazing how popular things like that are yet how little most of us do them... Our Club put a weekend together 2 yaers ago that had some 4WD trips and fun plus a heap of 1 to 2 hour presentations on the two evenings.

Invited a couple of other Clubs along and the presentations covered things like, Camp Cooking, GPS, Radio Comms, Photography, Local Ranger, etc plus had some Nav Runs, Poker Run etc.

Everyone reckoned it was FAT.

10th January 2011, 10:26 PM

Especially you too ET, I hope Doggy and Rossco can convince you to come over for the meet up.

the evil twin

10th January 2011, 11:04 PM

Especially you too ET, I hope Doggy and Rossco can convince you to come over for the meet up.

Hmm... Well, someone is going to have to go along to recover 'em or they'll never make it across the Nullarbor... Bwaahahaha.

I have LSL in 2012 so me and the missus are heading for Tassie... tentatively via the Great Central, Coober Pedy, Wilpena and coming back via the Great Ocean Road then Streaky Bay etc... I'll post up over in the Forum Meet. thread.

10th January 2011, 11:05 PM

Hmm... Well, someone is going to have to go along to recover 'em or they'll never make it across the Nullarbor... Bwaahahaha.

I have LSL in 2012 so me and the missus are heading for Tassie... tentatively via the Great Central, Coober Pedy, Wilpena and coming back via the Great Ocean Road then Streaky Bay etc... I'll post up over in the Forum Meet. thread.

haha, sounds good, might be able to pop in if we ever decide where we are going that is!

MudRunnerTD

11th January 2011, 11:06 AM

If I may be permitted to make an observation in the interests of accuracy tho. The figures for two snatch blocks IE triple line pull are incorrect. A standard triple line pull provides a 3:1 mechanical advantage not 4:1 reduces the load on the cable to 1/3rd not 1/4.

25 Degrees = Load (2,800kgs) + 45% = 4,060kgs X 300% for mud = 12,180kgs
PLUS the wieght of the Organic mass out the front (About 3m3) and we were up around the 15,000kgs!!

Put in a Snatch block and that is halved to 7,500kgs, and what is the Hi Mount rated at? 3,632kgs!
Should have done a triple line pull...Even a Triple Line pull would be 3,250kgs!,

In that example the "triple line pull" cable load will be 1/3rd or 5,000 Kg's hence the "triple" in the M.A. rig name.

Whilst on the subject... for everyone to keep in mind as well, the load on the snatch block is the sum of the loads on the cable so again to use the same example whilst the load on the cable is 5,000 Kg's the load on the strap or shackle securing the snatch blocks to the vehicle and tree (or whatever) is 10,000 Kg's.

Figure 7 Rig C shows a standard or "triple" line pull 3:1 M.A. rig most people are familiar with and utilise (2 Snatch blocks, 3 anchors)

Figure 8 Rig A shows how to get a 4:1 M.A from only 2 Snatch blocks and 3 anchors with the lowest load on the Shackles and Rigging using a compound rig which would indeed reduce the line load to 3,750 KG but is no longer a "triple pull". This method needs another rope or cable tho for the 2nd 2:1. In my case I carry a length of Dyneema for this and other uses.

http://www.ncstaff.net/oed/Pulley%20MA%20Systems.pdf

Again, my compliments on a top shelf amount of info. The more we get the info out there and the simpler it is then the safer it is for everyone and hopefuly the tragedies will diminish

Thanks for the correction Evil, you are correct 3:1 is the outcome.

Nice link mate, i have saved that to my computer, really sorts out the science of it.

http://www.ncstaff.net/oed/Pulley%20MA%20Systems.pdf

EVERYONE SHOULD READ THE LINK ABOVE.

MudRunnerTD

22nd July 2011, 04:45 PM

Hi guys,

Last post here was 12 Jan 2011.
Thought i would give it a bump to the top of the list as there are many many new members on this forum that would benefit from a good read of this thread.

Happy and Safe Recoveries for all.

Stay safe.

MR

ibs

10th August 2011, 10:39 AM

Hello,

this was an extremely useful post to read, thank you everybody that contributed to it!
taught me a lot :D

Phil21

14th August 2011, 04:22 PM

Superb post mate, we would all be wise to remember these things.

nemo

29th August 2011, 11:54 PM

Glad I read this and the one about snatch straps on tow balls, that would have been the first place I would of hooked the strap to.

Was out with a couple of mates last week and they were using the tow balls as recovery points, I will pass on the info.

growler2058

30th August 2011, 05:29 AM

Do pass it on mate it was only a week ago a woman was killed getting struck in the throat

Woof

30th August 2011, 06:21 PM

Just made this Sticky so it can be found easier.

DeJay

15th January 2012, 07:26 PM

Ive just cut n pasted this ready to print out and keep in my truck !!!! Thank you !!!

Dr Gary

25th January 2012, 03:23 PM

Turtle_au

7th February 2012, 09:25 PM

nice info, maybe do a pdf with checklist to print and put in glovebox.
I'm only a 4wd newbie and havn't had the joy of recovery yet, but have done plenty of winch/block work with moving machinery,
There are a couple of other points that I always consider.
What will happen if something breaks.
a) will the load stop moving or roll away uncontrolled? - use chocks or secondary lines to stop load and reposition/retighten often
b) how will the equipment react? - blocks become projectiles, cables become whips - use mats on cables, safety lines on blocks
c) where are the safest places? - know the danger zones - especially in the line of the pull and if anyone needs to go into these zones to move or adjust anyting, stop the pull
And remember "maximum planning = minimal effort = maximum safety"

Bigrig

7th February 2012, 09:57 PM

rusty_nail

7th February 2012, 10:15 PM

here you go guys, i have made and uploaded a PDF to my website. enjoy:

http://www.rgphotography.com.au/nic/nissanpatrolforum

can someone please let me know if its accesible as this is the first time ive done something like this.

cheers,

nic

Bigrig

7th February 2012, 10:21 PM

here you go guys, i have made and uploaded a PDF to my website. enjoy:

http://www.rgphotography.com.au/nic/

cheers,

nic

Top job mate!!! Well done!!!

rusty_nail

7th February 2012, 10:25 PM

Top job mate!!! Well done!!!

is it accesible? wasnt sure on the permissions...

Bigrig

7th February 2012, 10:26 PM

is it accesible? wasnt sure on the permissions...

I opened it on my iPad no dramas.

rusty_nail

7th February 2012, 10:27 PM

thanks mate. if you wanna put that link somewhere more accesible so it doesnt get lost in all the posts be my guest.

NissanGQ4.2

7th February 2012, 10:31 PM

here you go guys, i have made and uploaded a PDF to my website. enjoy:

http://www.rgphotography.com.au/nic/

can someone please let me know if its accesible as this is the first time ive done something like this.

cheers,

nic

yeh it works on my lappy no dramas :)

Silver

7th February 2012, 10:36 PM

rusty_nail

7th February 2012, 10:39 PM

Very nice Nic.

I learned some things.

If I could suggest a minor edit to the snatch block section - it might be useful to expand on the multiplying effect, contrasting where the cable goes from front mounted winch, to snatch attached to anchor, and then back to a recovery point near the front mounted winch, -v- the situation where the snatch is merely in line to change the line of pull a bit between the front mounted winch, and another anchor point past the snatch block.

I think in the former the multiplication is as you say, but in the latter, the multiplication effect is less, or nil?

lol silver i have no idea, i dont have a winch and im not too sure about all the math equations. i can change it if you want, but someone suggested to make a PDF outta the thread, so i did for the forum. let me know which part you want me to change and ill do so gladly

Silver

7th February 2012, 10:58 PM

lol silver i have no idea, i dont have a winch and im not too sure about all the math equations. i can change it if you want, but someone suggested to make a PDF outta the thread, so i did for the forum. let me know which part you want me to change and ill do so gladly

Crikey Nic, 2nd form science was a long long time ago for me!

The PDF says

The snatch block is a rated piece of equipment that allows the cable to run over a pulley and change direction too another tree or back to the winching vehicle. The awesome power of the Snatch Block is that as soon as you introduce a pulley within the line you HALVE the weight on the line!! Add 2 Snatch Blocks and you reduce the weight to 25% of the line weight at the hook!

Maybe it could say:

The snatch block is a rated piece of equipment that allows the cable to run over a pulley and change direction to another tree.

The cable can also run to the block and back to the winching vehicle.

The awesome power of the Snatch Block is that as soon as you introduce a pulley within the line that goes back to the winching vehicle you HALVE the weight on the winch!! Add 2 Snatch Blocks and you reduce the load on the winch to 33% of the actual load! There's a way to work out this mechanical advantage. One line from winch to anchor - winch is pulling 100%. Line from winch to anchor, through block and back to winching vehicle, winch is pulling 50%. The line is twice the distance to the anchor point - and the load is 1/2. Introduce another snatch block at the winching vehicle and run the cable back to the anchor - 3 times the distance, and the winch is doing 1/3 of the work.

There is a trap to this. If your winch is at max load of 3.6 tonnes, because the GU above is bogged to the chassis with a camper trailer, with the two snatch block set up above, then the anchor is bearing 3 x 3.6 tonnes - close enough to 11 tonnes. That 11 tonne load is also spread across the attachment points on the vehicle. Beware failing anchor points and make sure the shackles, tree trunk protectors and anything else that is carrying the full load is up to the job.

The other thing is that there is little or no mechanical advantage where the snatch block merely changes to the line of pull between winch and load a bit. The maximum effect is where the winch line does a 180 and goes back to the winching vehicle.

I'm sure someone could improve on this :-)

rusty_nail

7th February 2012, 11:40 PM

Crikey Nic, 2nd form science was a long long time ago for me!

The PDF says

The snatch block is a rated piece of equipment that allows the cable to run over a pulley and change direction too another tree or back to the winching vehicle. The awesome power of the Snatch Block is that as soon as you introduce a pulley within the line you HALVE the weight on the line!! Add 2 Snatch Blocks and you reduce the weight to 25% of the line weight at the hook!

Maybe it could say:

The snatch block is a rated piece of equipment that allows the cable to run over a pulley and change direction to another tree.

The cable can also run to the block and back to the winching vehicle.

The awesome power of the Snatch Block is that as soon as you introduce a pulley within the line that goes back to the winching vehicle you HALVE the weight on the winch!! Add 2 Snatch Blocks and you reduce the load on the winch to 33% of the actual load! There's a way to work out this mechanical advantage. One line from winch to anchor - winch is pulling 100%. Line from winch to anchor, through block and back to winching vehicle, winch is pulling 50%. The line is twice the distance to the anchor point - and the load is 1/2. Introduce another snatch block at the winching vehicle and run the cable back to the anchor - 3 times the distance, and the winch is doing 1/3 of the work.

There is a trap to this. If your winch is at max load of 3.6 tonnes, because the GU above is bogged to the chassis with a camper trailer, with the two snatch block set up above, then the anchor is bearing 3 x 3.6 tonnes - close enough to 11 tonnes. That 11 tonne load is also spread across the attachment points on the vehicle. Beware failing anchor points and make sure the shackles, tree trunk protectors and anything else that is carrying the full load is up to the job.

The other thing is that there is little or no mechanical advantage where the snatch block merely changes to the line of pull between winch and load a bit. The maximum effect is where the winch line does a 180 and goes back to the winching vehicle.

I'm sure someone could improve on this :-)

using your info i have update the PDF mate. i also added two of the other posts which i felt would go well in the doc. you should be able to download the PDF of view it for all those interested

heres the link again so its more recent and easy to see:

http://www.rgphotography.com.au/nic/nissanpatrolforum/

cheers

nic

Silver

8th February 2012, 12:55 AM

thanks again Nic for taking this on - it is pretty impressive

GQshorty

18th February 2012, 06:32 PM

thanks guys very helpful:)

Alburypete

27th February 2012, 08:36 PM

Thanks, thought provoking and informative.

benmatters

5th April 2012, 05:50 PM

What about explanining basic 3 to 1 adavantages, or about spliting your load , instead of pulling 1 ton why not only pull 1/2 ton

MudRunnerTD

5th April 2012, 06:40 PM

What about explanining basic 3 to 1 adavantages, or about spliting your load , instead of pulling 1 ton why not only pull 1/2 ton

If you go back to the first page and have another look you will find the answers are there, also the top of the second page posted by EvilTwin also addresses mechanical advantage in basic maths.

Here is a couple of exerts

Snip.

Basic Winching and the Affect of Slope.

Winching on flat ground in a straight line is pretty well as safe as houses as long as you adopt safe work practise. The load is well within the ratings of the equipment on every 4WD. But who does that?

Standing clear, Using a Winch Blanket and connecting to a Rated Recovery Point on the vehicle is all that should be needed to extract the vehicle.

How much are you really pulling up that hill when you are swing off a winch cable on a 30Degree slope? And what about when you are bogged to the axles or sitting on your belly in the mud? Sticky Otways Mud?

What if you have to winch around a corner? How do you do that?

There are basically four different types of resistance that you will encounter while off roading that affect the load on the winch. These include:

1. Surface Resistance.
2. Slope Resistance.
3. Bog Resistance.
4. Damage Resistance.

The figures below come from extensive reading and research and a dash of commonsense. As explained earlier, there is no comprehensive list of regulations for recovery that contain this information.

To move or pull a 4WD on a firm flat bitumen surface requires a force of just 10% of the loaded weight of the vehicle. To do the same on gravel or grass increases this to about 33% of the loaded weight of the vehicle.

Throw an incline in and that maths increases significantly.The percentages need to be added to the loaded weight and can change things dramatically and quickly increase the weight being recovered to far beyond the capacity of the equipment.

For an Incline, or Up Hill, the following extra weight should be added to the loaded weight of you vehicle as a guide:

• 15degree Slope == add +25% of the loaded weight

• 30degree Slope == add +50% of the loaded weight

• 45degree Slope == add +75% of the loaded weight

On flat ground no change is required

For a Decline, or Downhill, the following weight can be deducted from the loaded weight of you vehicle as a guide:

• 15degree Slope == subtract -25% of the loaded weight

• 30degree Slope == subtract -50% of the loaded weight

• 45degree Slope == subtract -75% of the loaded weight

Basic Winching and the Affect of MUD.

But what if your bogged? If your fourby is bogged in the Mud then the depth of the bog will have a massive affect on the loaded weight of the vehicle.

Below is a guide only for calculating the dead weight of the vehicle when in mud.

Bogged to the Base of the Wheel Rim, you will require a pull of 100% of the load

Bogged to the wheel Hub, the weight doubles! You will require a pull of 200% of the load

Bogged to the Belly or the Chassis and it is x3! You will require a pull of 300% of the load

And lets face it, the later is when winches are really being asked for.

Apply these weight variants to ALL of your RECOVERY gear!

Consider these variations when you are looking at your vehicle and considering how you will extract it form its position. Consider being stuck in the mud to the chassis on a 25degree slope!!!

Pounds Vs Kilograms – the Real Story.

Why do we have winches on our vehicles that quote the mass weight strength of the line pull in Imperial Pounds when we are living in a Metric System of Measure.

It because the bench mark brands of winches originate in the USA where it is all about pounds.

And lets face it 8000lbs sounds much tougher than 3600kgs! Imagine the Warn High Mount called the 3.6.

Get to know your gear and get to know it in the Metric world. Do the conversions and document them in your vehicle if you cant remember them. Send it to yourself as a text message on your phone so you never forget. This will save your life.

For the record - 1lb equals 0.454kgs, or 1kg equals 2.2lbs.

8000lbs = 3632kgs
9000lbs = 4086kgs
10,000lbs = 4540kgs
12,000lbs = 5448kgs

Scenario

So, your average GU Patrol for example has a loaded weight of 3.3t (2.2t tare by 1.5t). Your stuck to the chassis, so you will need to pull 9.9t out of the muck (3.3t x 300%)

Throw on a camper trailer (1t) and your Nissan’s winch and recovery gear needs to deal with 12.9t!

Now look at the list above and see the problem you are in!!

Snip

Enter the Snatch Block!

An introduction to the Power of the Multi-Line-Pull.

We’ve just worked out that, by itself, your winch is in big trouble. The electric winch has many limitations and is not the be all and end all. By itself it is very handy and will give many an inexperience four-wheel driver a false sense of security and confidence and can get you into more trouble than it can get you out of if in the wrong hands.

This is why we like to use the humble Snatch Block. You cant have too many of these. If every one has one then you may have many on a hill. This is all good.

The snatch block is a rated piece of equipment that allows the cable to run over a pulley and change direction too another tree or back to the winching vehicle.

The awesome power of the Snatch Block is that as soon as you introduce a pulley within the line you HALVE the weight on the line!! Add 2 Snatch Blocks and you reduce the weight to 33% of the line weight at the hook!

Add Three? Well, then you will reduce the load on the winch to 25% or so of the load on the hook. This is called a Triple Line Pull. It is slow but very effective.

Remember, every time you add a Snatch Block you reduce the weight significantly, but also reduce the speed of the winch but double the power so who cares.

**Very Important.. The mathematics that we have set out here is only true if the pulley is set up to allow the pulley wheel to turn with the cable.

The Weakest Link

**Very Important

Remember that the main reason that we introduce Snatch Blocks is to halve the weight on the winch effectively allowing us to pull far in excess of the pulling power of the winch.

Often when Snatch Blocks are introduced the winch line is used up in the double or Triple line pull and we have to use a Winch Extension Strap. What is the rating of this strap?? The more Line pulls the more likely that you can introduce a weight beyond the breaking strain of the strap. This is very easy to do and it is disastrous.

Massive loads are placed on your recovery system when introducing Snatch Blocks; so think about all of it every time you use it, when ever you pull it out and after you pack it away!

The Final Check List

1. Is your recovery Hook rated and to what level?

2. What is the breaking strain on the Winch Extension Strap?

3. What about the Tree Truck Protector?

4. The Shackle?

5. What does my Winch cable look like?

6. What does it look like now?

7. Did I pack it away and re-spool it properly?

8. Have I lubricated it?

9. Is that winch cable that I will hang off one day just a rusty Birds nest on the front of the vehicle or re-spooled and lubricated ready for use?

10. Have I put any of my gear under extreme load before? And should it be replace?

Rule Number 1

Work Safely, Protect Life.
Determine the load,
Assess the Environment.

THINK!!

Enjoy the drive, Tread lightly

Special thanks to Australian 4WD Action for being a great Resource

Cheers MudRunnerTD
AKA Darren

Firstly, what a great Post Darren,

I am also a Driver Trainer and Rescue Systems Instructor with the S.E.S. which brings a heap of personal satisfaction which I am sure you get as well doing similar with your Club.

If I may be permitted to make an observation in the interests of accuracy tho. The figures for two snatch blocks IE triple line pull are incorrect. A standard triple line pull provides a 3:1 mechanical advantage not 4:1 reduces the load on the cable to 1/3rd not 1/4.

25 Degrees = Load (2,800kgs) + 45% = 4,060kgs X 300% for mud = 12,180kgs
PLUS the wieght of the Organic mass out the front (About 3m3) and we were up around the 15,000kgs!!

Put in a Snatch block and that is halved to 7,500kgs, and what is the Hi Mount rated at? 3,632kgs!
Should have done a triple line pull...Even a Triple Line pull would be 3,250kgs!,

In that example the "triple line pull" cable load will be 1/3rd or 5,000 Kg's hence the "triple" in the M.A. rig name.

Whilst on the subject... There is one other factor in M.A. rigs for everyone to keep in mind as well, the load on the snatch block is the sum of the loads on the cable so again to use the same example whilst the load on the cable is 5,000 Kg's the load on the strap or shackle securing the snatch blocks to the vehicle and tree (or whatever) is 10,000 Kg's.

Here is a cracking good article on M.A. Rigs and loads to illustrate.

Figure 7 Rig C shows a standard or "triple" line pull 3:1 M.A. rig most people are familiar with and utilise (2 Snatch blocks, 3 anchors)

Figure 8 Rig A shows how to get a 4:1 M.A from only 2 Snatch blocks and 3 anchors with the lowest load on the Shackles and Rigging using a compound rig which would indeed reduce the line load to 3,750 KG but is no longer a "triple pull". This method needs another rope or cable tho for the 2nd 2:1. In my case I carry a length of Dyneema for this and other uses.

http://www.ncstaff.net/oed/Pulley%20MA%20Systems.pdf

Again, my compliments on a top shelf amount of info. The more we get the info out there and the simpler it is then the safer it is for everyone and hopefuly the tragedies will diminish

Hey Ben i hope the posts above clarify and fill the gaps you were trying to address. All good mate and i appreciate this thread getting bumped as often as you like.

Stay safe this Easter.

Cheers MR

BubbaChang

7th April 2012, 04:04 AM

Wow so wot winch systems and gear would you recommend?

benmatters

8th April 2012, 02:07 AM

Ok yes so all that stuff about degreases is good, some basic load sharing should be placed in hear for example if I was to pull a load that was 100kg and used a simple 3 to 1 I would be only pulling 1/3 of the load there for the load on my gear would only be a 1/3

benmatters

8th April 2012, 02:22 AM

MudRunnerTD

10th April 2012, 07:17 PM

I do not mean to be backward, I do understand what you have posted before, but I cannot stress how important it is to fully explain your advantages in say a 3 to 1. A lot of people just don’t understand, I do not know how to post diagrams to explain this but I was hopping you could. Just remember there are a lot more than just your basic 3 to 1, these things need to be illustrated so people can fully understand how they work.

I appreciate your input Ben, i have tried to address the 3:1 ratio and the use of a Snatch Block in the post above at the start of the second Snip.

I Highly Recommend that everyone clicks on the link provided by EvilTwin and scroll down to about page 6 where it starts to get really interesting. There are some great pics on page 8

Check it out here Power of the Snatch Block (http://www.ncstaff.net/oed/Pulley%20MA%20Systems.pdf)

Black Rock

12th April 2012, 03:52 AM

I noted advice on keeping winch cable lubricated. No data on that from Warn, so can you help with the type of lube recommended. I have a mudflap rubber "skirt" covering the front of the winch, hopefully to keep some of the crud out.

Mine -- WD 40 twice a month (when not in use), when in use (wash, dray - watch out the fingers for the split pieces on cable) then any kind of oil can do the job

gilly81

12th April 2012, 05:43 PM

A great read! Certainly helped me choose the right recovery gear a few weeks ago..

Wine_maker

27th April 2012, 06:36 PM

everything goes wrong!

http://www.youtube.com/watch?v=y33vxMGj4qM&feature=player_embedded

MudRunnerTD

27th April 2012, 07:17 PM

And its That easy folks!!! I bet old mate in the Cruiser rated his ability quite highly, seemed to be a well setup car. Plenty of space cowboys that buy cars that are already modded too.

Shame the guy did not get the whole thing on Vid but certainly a good vid, thanks for posting.

gregs

27th April 2012, 11:37 PM

the guy trying to push the navara was lucky he didn't get squashed as well when he started to walk up towards to 80 series, it only needed to roll over again and it might have been goodnight irene. I think navara driver should consider himself lucky buy a lotto ticket for himself and a couple for his mate, plus a few late nights helping his mate fix his cruiser.

alexx

9th July 2012, 02:48 PM

I liky this post. Thank you Mudrunner

threedogs

9th July 2012, 03:18 PM

Great info , But seems to me that the majority of people here have not been in a club or done any driver awareness or recovery classes IMO. You can form a lot a bad habits from not being taught by someone QUALIFIED in this field. Same goes for driving techniques, see it all the time in the bush. so number one attend an accredited course be it recovery or driving, You'll be much the wiser and safer for it, Then you can pass on this knowledge to someone starting out. Just look at the TOWBALL thread. people still dying. do a course and stay safe

Agree about the cowboys to, plenty of cash to trick up a truck but no idea what so ever on how to drive it properly OFF ROAD

Old Wal

2nd August 2012, 07:23 PM

Thanks MudRunnerTD ( Darren ) for your post.
Very informative. Of particular interest to me was your highlighting " the weakest link ". I have tried to explain this to my mates ( usually after reaching a higher state of consciousness via the carton of enlightenment ).
Haven't had a lot of success. They argue that because the load on the winch is reduced , likewise on the cable. I usually use the analogy of truckies hitches, Tie one hitch & I can't break the rope. Tie multiple hitches & I can break the rope
Thanks once again ,
Old Wal

Les Penrose

3rd September 2012, 05:22 PM

Thanks, great explanations

LukeV

21st January 2013, 11:21 PM

Thanks to everyone involved in this thread. Great read, and some quality info.

NP99

28th March 2013, 12:33 AM

everything goes wrong!

http://www.youtube.com/watch?v=y33vxMGj4qM&feature=player_embedded

Old matey just standing there as the vehicle tumbles towards him!!!

Newiereef

1st April 2013, 01:32 PM

So useful for the beginner.thankyou

thelawz

1st April 2013, 08:00 PM

Thanks, very usefull information indeed. And seeing the Cruiser makes you realise how quick thinks can go wrong. I will buy a couple more snatch blocks.

Winnie

6th August 2013, 12:32 PM

Look at how far a bull bar can travel when things turn bad.

Got sick of Motorculture so gone back to Tappa

MudRunnerTD

6th August 2013, 12:41 PM

Wow!!!! Imagine being in the way of that!

threedogs

6th August 2013, 01:37 PM

There is footage years ago of two grey nomads exploring up the NT ,when one got bogged not knowing what to do they hooked strap around the top of the stuck 4x4s bull bar.
Ripped the bulbar clean off the 4x4 not sure if anyone was injured, but pride was surely dented

AJTich

29th October 2013, 10:23 PM

Thanks for all of this Muddy. So much great information... That is fantastic.

Gu777

10th November 2013, 09:39 PM

Awesome information that is probably overlooked by so many, thanks I'm learning so much on here

kind

11th November 2013, 06:55 PM

MudRunnerTD

11th November 2013, 07:33 PM

Great write up guys one thing I have learned the hard way is to make sure my winch also has reverse gearing. Puts a nugget in ya pants trying to go down a hill backwards and dropping a few feet from the winch letting go

Hi Kind,

Be very careful winching in reverse down hill. Sometimes it's necessary and such is life but understand what is going on.

A Lowmount winch (98%) of winches have an internal brake inside the drum that functions only when the winch stops. It them holds the winch in the stopped position. Your Lowmount winch actually just let's the brake out a little and when letting yourself down on the winch that internal drum brake gets very very HOT. This is the main reason that Lowmount winches are not ideal synthetic Rope. It melts. A protective sheath is recommended on the first wraps of rope.

If you run a steal cable then its not as concerning. Just be aware. It like riding the clutch or driving around with the handbrake on. It gets Hot. Play safe.

bear3103

11th November 2013, 08:02 PM

Ime only new to the hobby and was wondering, on the back off the gu above the towbar is a metal loop, is that a good recovery point or should I invest in the towbar hitch????

kind

11th November 2013, 08:40 PM

Ime only new to the hobby and was wondering, on the back off the gu above the towbar is a metal loop, is that a good recovery point or should I invest in the towbar hitch????

Mate if you try and snatch off that it will break first go invest in a hitch or take the towbar out and put rhe strap insode and put the pin back though.

bear3103

11th November 2013, 11:15 PM

That's what I was wondering, I will invest in the hitch for sure.

NP99

29th September 2014, 11:02 PM

http://youtu.be/a_prLiK97v0

Lucky, very lucky.....

motoracer

10th October 2014, 05:20 PM

Not to resurrect an old thread, but thanks for this, it's exactly the kind of stuff I hoped to find here . . .

Golioth

28th October 2014, 04:14 PM

thanks for that. some great info there for a newbie like me

krbrooking

7th March 2015, 01:22 PM

Just found this on you tube. Thought it would be good to post it to show how panic can affect the situation and how easy it can go from bad to really bad.

http://youtu.be/f8trkgFX6wI

Sent from my iPhone using Forum Runner

threedogs

7th March 2015, 01:25 PM

That's what I was wondering, I will invest in the hitch for sure.

Make sure its rated to the full capacity of your Patrol as well

threedogs

7th March 2015, 01:29 PM

Trouble with that recovery was they already had footage of that crossing and decided to have a play, and it went bad

Rossco

7th March 2015, 01:48 PM

krbrooking

7th March 2015, 02:42 PM

Exactly my thought Rossco. Extremely top heavy you can see how much body roll they are getting on the crossing. The other thing I can't figure out is why were they pulling on such an angle it should have been a straight pull.
@TD: So right, what confused me is he says how often they have crossed it and the fact there was footage of him going over but the one camera man didn't get footage so he decided to go back on top of which he went straight back over the same tracks where he would have known the surface had already been broken.

Sent from my iPhone using Forum Runner

threedogs

7th March 2015, 02:55 PM

I don't want to sound like a know all, but both their vehicles, especially the 79 are very top heavy. Heavily loaded cargo, roof rack and tiny on the roof as well. Not surprising it took very little to tip that thing over. I know those guys like to take a lot of toys with them, just something to think about that's all, especially if you want to push the limits.

I suppose they push the envelope all for great footage,
I'll try to find out what the breakage rate was,
I suspect that LUX didnt fair well on some of the terrain

P4trol

7th March 2015, 10:33 PM

They used some of the footage, with different narrative, for the debut of the series. This clip shows the rest of the footage.

Apart from a few jumps by the lead characters + cameraman over a live snatched strap, they're quite welcome to drown their sponsored vehicles.

the evil twin

7th March 2015, 10:40 PM

snip...

Apart from a few jumps by the lead characters + cameraman over a live snatched strap, ...

Thats disgraceful.

All snatch straps should be humanely euthanised by putting them in the freezer for an hour or two prior to use.
Taunting them by jumping around just causes undue stress

Or is that Mud Crabs... dunno been a while since I had one...

P4trol

8th March 2015, 08:51 PM

Autocorrect... Makes me sound like I'm from a call centre.

faw33

12th March 2015, 02:12 PM

Great work on here guys. very helpful

Throbbinhood

13th March 2015, 10:24 AM

Hey all, few quick questions after reading.

So, say I'm bogged deep, and pulling up hill, doing a double line pull. Say, just as a number, with the double line pull, weight on the winch is 5t. Does that mean weight on the pulley is 10t, and as such, the weight on the shackle holding the pulley is also 10t? I only ask, because I haven't seen too many 10t shackles around. Would using two shackles help spread the load, or is it just making it a more lethal projectile?

Also, if I need to winch a car behind me up a hill, but there is no room to turn around, any drawbacks to hooking the winch to a pulley on an anchor say, to my front left, and from that pulley back to their car - provided I can get the rope to their car without hitting mine or anything in the process?

the evil twin

13th March 2015, 12:01 PM

snip...

So, say I'm bogged deep, and pulling up hill, doing a double line pull. Say, just as a number, with the double line pull, weight on the winch is 5t. Does that mean weight on the pulley is 10t, and as such, the weight on the shackle holding the pulley is also 10t? I only ask, because I haven't seen too many 10t shackles around.

1. Don't try and pull a deeply mired vehicle (uphill, downhill or level) unless you have done everything you can to reduce the effect of the Bog and/or stiction IE some shovel work.
2. If you have 5 ton on the winch on a double line pull then you must have a Unimog on the other end
3. You don't need a 10 ton shackle for recovery work. Shackles are rated to Lifting Standards and depending on grade, a 10 ton shackle will be good for 40 to 70 tons, weigh about 10 KG and be the size of a large dinner plate.

snip...

Also, if I need to winch a car behind me up a hill, but there is no room to turn around, any drawbacks to hooking the winch to a pulley on an anchor say, to my front left, and from that pulley back to their car - provided I can get the rope to their car without hitting mine or anything in the process?

You will find that a very difficult evolution in a practical world IE if there isn't room to turn then there usually isn't room or ideally placed anchor points to rig the redirects required

In a theoretical world you can do it as it is no different to a redircet but in practice don't forget you will need to allow for a friction loss (or load depending) of 10% for each snatch block you use

threedogs

13th March 2015, 12:40 PM

Thats disgraceful.

All snatch straps should be humanely euthanised by putting them in the freezer for an hour or two prior to use.
Taunting them by jumping around just causes undue stress

Or is that Mud Crabs... dunno been a while since I had one...

you saying its a long time since you had crabs/crab lol

Throbbinhood

13th March 2015, 12:45 PM

You will find that a very difficult evolution in a practical world IE if there isn't room to turn then there usually isn't room or ideally placed anchor points to rig the redirects required

Sorry, I didn't quite phrase my question that well. It's less of a 'not being room to turn', and more, say im going up a hill, and turning is impractical because of angles. I could go up, turn around, and come back down, but that would mean having to reverse back up the hill, which would present it's own set of dangers, and may not be practical. But if it effectively works as a redirect then it should be sweet :)

threedogs

13th March 2015, 01:00 PM

you halve the effort you are still pulling what was it 5ton
twice as slow

the evil twin

13th March 2015, 01:49 PM

Sorry, I didn't quite phrase my question that well. It's less of a 'not being room to turn', and more, say im going up a hill, and turning is impractical because of angles. I could go up, turn around, and come back down, but that would mean having to reverse back up the hill, which would present it's own set of dangers, and may not be practical. But if it effectively works as a redirect then it should be sweet :)

Yeah, it's the old "in theory" thing.

In practice trying to rig from the centre of your vehicle out to one side or the other then back down to the stranded vehicle is almost always impractical due to not having enough snatch blocks, winch extensions etc .

Put it this way, with a standard length winch cable, one or two snatch blocks and one vehicle behind the other it just is not going to happen.

You are going to have to rig forward at a small enough angle to not side load your winch OR use a snatch block redirect to get to the side THEN, another snatch block to redirect back and I would suggest at least 1 probably 2 more to redirect onto the front of the stranded vehicle and/or clear the ground

That is a lot of cable and blocks and you still have only 1:1 line pull

One option would be rigging his vehicle to the rear of yours and winching/driving in concert using the gear on your vehicle to give you a 4:1 advantage on your winch.

Throbbinhood

13th March 2015, 01:58 PM

One option would be rigging his vehicle to the rear of yours and winching/driving in concert using the gear on your vehicle to give you a 4:1 advantage on your winch.

That sounds like the go. Thanks for the help mate.

Throbbinhood

22nd March 2015, 07:06 PM

Another quick one.

Found a bloke on the weekend who went too quick around the corner and was almost over the side, car was balancing on its chassis and would have been a long way down. We had two cars with winches to recover, and chose to run pulleys off a tree to redirect and basically pull him sideways (our thinking here was that it pulls our cars towards safety as well as his, rather than a direct pull which may have just pulled us towards the edge).

Question is, if only one of us had a winch and was struggling to pull sideways with only the redirect, would have a pulley from the stuck vehicle back to the tree with the redirect give us an advantage?

the evil twin

22nd March 2015, 07:53 PM

Yes .

carsurgeons

16th April 2015, 10:41 AM

thanks for the good info. we expect a lot from our winch cables .

Throbbinhood

18th June 2015, 04:55 PM

the evil twin

18th June 2015, 07:37 PM

I may have missed this elsewhere

When I use a pulley to setup a mechanical advantage and hence reduce load on the winch, do I also reduce the load on the rope/shackles/pulleys?

For instance, say I'm doing a 3T winch pull, with no pulley it's 3T on the winch, rope, straps. With a pulley involved, it's 1.5T on the winch, is it also 1.5T on everything else?

1.5T on the winch drum
1.5T on the winching vehicle anchor point and any rigging
1.5T on the cable from the winch to the snatch block
1.5T on the cable from the snatch block back to the vehicle anchor point (it is the same cable so must have the same load)
3.0T on the snatch block (2 cable loads at 1.5T each)
3.0T on the anchor point of the snatch block and rigging to whatever you anchored the snatchie too.

Throbbinhood

19th June 2015, 10:52 AM

1.5T on the winch drum
1.5T on the winching vehicle anchor point and any rigging
1.5T on the cable from the winch to the snatch block
1.5T on the cable from the snatch block back to the vehicle anchor point (it is the same cable so must have the same load)
3.0T on the snatch block (2 cable loads at 1.5T each)
3.0T on the anchor point of the snatch block and rigging to whatever you anchored the snatchie too.

Thanks mate

Is there ever a case where you multiple or increase the load on equipment by hooking up redirects/double/triple line pulls? Or for the most part it halves, and stays the same as original on things like pulleys and anchor point the pulley is connected to?

the evil twin

19th June 2015, 12:58 PM

Thanks mate

Is there ever a case where you multiple or increase the load on equipment by hooking up redirects/double/triple line pulls? Or for the most part it halves, and stays the same as original on things like pulleys and anchor point the pulley is connected to?

Halving loads etc only works in a perfect world.
Real world use means snatch blocks, pulleys etc introduce their own loads IE depending on dia, cable type etc it may be that you only get a, say, 45% reduction instead of the full 50.
That is no biggee unless you are up on the ragged edge.

The other thing to be aware of is Sling Load Angle on bridles, very common, or if loading a redirect which is quite unusal but may be handy if recovering or winching around a curved path

Throbbinhood

19th June 2015, 02:47 PM

Halving loads etc only works in a perfect world.
Real world use means snatch blocks, pulleys etc introduce their own loads IE depending on dia, cable type etc it may be that you only get a, say, 45% reduction instead of the full 50.
That is no biggee unless you are up on the ragged edge.

The other thing to be aware of is Sling Load Angle on bridles, very common, or if loading a redirect which is quite unusal but may be handy if recovering or winching around a curved path

Thanks mate - I just want to make sure I don't ever increase the load on components. Would hate a triple line pull to result in a 3t pull being 9t on the snatch block, but from the sounds of it, the snatch block only ever gets the original load sort of thing.

Maxhead

19th June 2015, 05:29 PM

1.5T on the winch drum
1.5T on the winching vehicle anchor point and any rigging
1.5T on the cable from the winch to the snatch block
1.5T on the cable from the snatch block back to the vehicle anchor point (it is the same cable so must have the same load)
3.0T on the snatch block (2 cable loads at 1.5T each)
3.0T on the anchor point of the snatch block and rigging to whatever you anchored the snatchie too.

Thanks for the info mate, often wondered about this particular question

MudRunnerTD

18th August 2015, 09:43 AM

Death By Towballs and Hitch Receivers left to Rust.

click on this pic and consider your receiver.

60552

Winnie

18th August 2015, 09:48 AM

That would be a boat trailer for sure and that receiver must have had a crack in it or something and allowed it to fill with salt water.
Even so though, it is a bloody good reminder. I would say that driver was very lucky he wasn't travelling at any great speeds when that came off!
Surely you would have noticed that kind of damage earlier?

rusty_nail

18th August 2015, 09:53 AM

Winnie

18th August 2015, 10:26 AM

i couldnt get my towball hitch out recently when i was out 4wding(i wanted to do a recovery but we had to work out other methods out. anyway, turns out the pic was rusted as fck and the hitch had swollen with rust and just wouldnt budge. it took me a week of soaking wd40 followed by attaching the towbar to a VERY short chain which was wrapped around a telegraph pole and little bit by little bit gently nudging it out. needless to say i replaced the culprit and cleaned out all the left over rust!!!

You'd be surprised how often they are like that. When my mate bought his GQ it did not have a pin through the tow receiver but the previous owner used it as a tow vehicle... the rust was keeping it in and my mate had big troubles trying to get it out. The tow bar had to come off in the end and oxy and press sorted it out.

Rock Trol

18th August 2015, 11:05 AM

Wow! Better to remove hitch when not in use and dry it off if wet or after washing. The one that broke looks like it's made of cardboard.

Throbbinhood

4th January 2016, 10:46 AM

Hey guys, another question..

Tree trunk protectors, are their rating's use when used end to end? It's sort of hard to explain, but around the tree, isn't the strap in effect doubled up?

Just wondering if it's safe to use a tree trunk protector as a short winch extension strap.

MudRunnerTD

4th January 2016, 02:26 PM

Throbbinhood

4th January 2016, 02:31 PM

I would use it as a short extension without hesitation.

No need to double it up? As in, the two eyes of the strap on one end, and a just looped through the strap?
Or fine to just go one eye to winch hook, other eye to shackle elsewhere type thing? Or are both ways fine?

I only ask as I did a double line pull yesterday, found myself a bit short on winch rope, so had tree trunk protector around tree to a shackle, with another tree trunk protector with one eyelet on that shackle, other eyelet on a snatch block. Just want to make sure this is ok to do in future..

Andy76

30th September 2016, 08:41 AM

Being new to the group and new to 4x4 the information provided is a great help and very informative
Thanks

Kimbo63

30th September 2016, 12:00 PM

4bye4

30th September 2016, 01:03 PM

Here is what happened when westy tried that lol
69239

You need to attach as close to the bottom of the pole as possible, not to the top. Never underestimate the power of the mighty Nissan!

MudRunnerTD

16th March 2017, 08:45 AM

I need to leave this here too.

When it goes wrong it is vicious. This guy was lucky he used his arm as a cable dampener instead of his head. That hook would have gone straight through a Child.!

Shit gets Real, Fast!

http://www.nissanpatrol.com.au/forums/images/imported/2017/03/136.jpg

STOP, THINK, BE SAFE.

TAKE 5

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GQtdauto

16th March 2017, 11:20 AM

After seeing that photo it's made me rethink safety when doing recoveries .

Mike02Ti

16th March 2017, 11:30 AM

As a rigger I have been amazed at the silly practices /no common sense and lack of proper education on the subject of recovery.
From using tow balls to snatch people out to incorrect shackles , sizes of snatch straps and recovery points not fit for use.

Its not hard nowadays to get all the correct rated gear at a decent price. There isnt an excuse to not have a damper of some sort as you can also use a heavy piece of cloth of some sort. We can now get soft shackles which adds to the safety and eliminates a massive hunk of steel flying through the air.
People standing way too close and in the wrong position when involved in a recovery is another.

How often do people really check their gear? Do they throw that snatch strap away after a few recoveries like you are meant to?
Does the person doing the recovery snatch actually know what the hell they are doing and not going to take off at 400km/h to get you out?
Is there another safer way to get out? ie winch or recovery boards.

One things for sure , i wouldnt want myself or anyone else involved in any recovery ending up like the guy above or worse. Why risk it for an extra few mins to do things properly. Yes sometimes there is equipment failure but its very rare with the right equipment fit for use and the correct techniques used in recovery. Besides if you know what may go wrong you should be able to help prevent it in some way.

I hate the practice of people leaving shackles on their vehicle driving around town too (thats another issue altogether)

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threedogs

16th March 2017, 12:18 PM

Im glad not one of my recovery points has failed.
and as I told ppl at point of sale "its a piece of recovery gear
it will need replacing at some stage" If they listen thats another
thing,

20th May 2019, 05:03 PM

Thought you might be able to add this safety check onto your awesome list thanks MudRunnerTD mate!

“Always check your tree trunk protectors for eight legged hitchhikers before carrying it around your neck to the next tree needed”

http://www.nissanpatrol.com.au/forums/images/imported/2019/05/267.jpg

Pretty sure a cheeky Ellis Track Huntsman got me on our weekend adventure just conquered, itchy friggin nip on the back since Saturday arvo I tells ya, lol :-)

http://www.nissanpatrol.com.au/forums/images/imported/2019/05/268.jpg

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jack

20th May 2019, 06:55 PM

20th May 2019, 07:01 PM

Funny you say that Jack mate, even Tapatalk wouldn’t let me add the picture initially until I cropped it a bit, must have thought it was a real nip and censorship blocked it, lol :-)

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mudnut

14th November 2019, 05:35 AM

https://www.youtube.com/watch?v=kW304fXuG1M

This guy seems to know his stuff.

The small problem of dyneema rope pulling out of the anchor point is more likely with some winches when using the first layer on the drum.

mudnut

14th August 2020, 02:30 PM

https://www.youtube.com/watch?v=Z3ChEkSsxpE

This is a good video for discussion.

MudRunnerTD

27th September 2020, 01:15 PM

This should not have happened. A Daughter A Sister, A Friend. A Young life Lost.

Think about what you are doing. Always consider the worst case scenario and clear the safety zone.

http://www.nissanpatrol.com.au/forums/images/imported/2020/09/151.jpg

http://www.nissanpatrol.com.au/forums/images/imported/2020/09/152.jpg

RIP

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mudnut

4th October 2020, 04:56 PM

This bit of kit makes sense. https://www.youtube.com/watch?v=5EaK4mpR5eQ

https://www.youtube.com/watch?v=wjv51ovrE30 Another video for not using towballs.

PeeBee

4th October 2020, 06:33 PM

Thanks Craig, great product, so simple, have flicked an email off to the US to get a price for one posted, either to Aussie or to my post box in florida USA.

MudRunnerTD

5th October 2020, 03:47 PM

Thanks Craig, great product, so simple, have flicked an email off to the US to get a price for one posted, either to Aussie or to my post box in florida USA.

Price for 2 bro. I want 1, I don't need 1 but I bloody want one!!!

PeeBee

5th October 2020, 04:47 PM

Price for 2 bro. I want 1, I don't need 1 but I bloody want one!!!

Done, have resent the email requesting pricing on 1,2,3,4 and 5 units shipped to either Melb or Florida USA. They are $147 USD each for a single. I can see an immediate use when using extension ropes - wish I had this when I did that tyre on the way into Burgoynes on the side of a tree-less hill and finding an anchor that was within the strap limits was more difficult that you would think possible. Have sent a price request to X-Lock and ASR for comparison

PeeBee

8th October 2020, 01:32 PM

OK guys, finally got a reply from the US manufacturer, and the price is firm at $147 USD each up to a quantity of 20 units, then there is a 10% discount applied. The postage is ridiculous - $40US each, so 20 units would be $800USD - stuff that. I am sure my FEDEX mailbox in Florida will beat that hands down, generally half to a third of the USPS.

Let me know interest - do your numbers guys as its USD. I am going to hold off until I get back to work to place the order. Happy to put it on my credit card and you simply direct deposit the amount when its all said and done.

MudRunnerTD

8th October 2020, 02:09 PM

PeeBee

8th October 2020, 04:10 PM

Wow! that is getting up there Phil. That will be $200AU for sure. I wonder if i can make one out of a Nylon or Alloy Block?... Hmmm,

Put it into context - its a drop compared what you have spent so far, probably what all of us have spent on our hobby/passion. I am sure you could make one, but this one is actually load rated at 20,000lb, so must have undergone some testing. We don't know what it is made of either - looks like some sort of alum. alloy, but it could be a forging thats been tumbled and plated. I think I will go with the rated item. As i said previously, Its another trick I could have used in the past. Without this it took 3 hrs out of my weekend. I will order mine as soon as i get back to work, and let you know if anyone wants to jump on. Unfortunately the group discount is not that favourable.

PeeBee

16th December 2020, 11:20 AM

OK, ordered one of these puppies today
https://www.safe-xtract.com/tutorials/x-lock-uses/
$155USD plus delivery ex USA

mudnut

16th December 2020, 12:55 PM

I think the biggest benefit is running the winch on the first layers of rope which gives its rated capacity.

https://www.youtube.com/watch?v=HXPqkh3F8qg the credits are hilarious.

PeeBee

16th December 2020, 03:18 PM

I think the biggest benefit is running the winch on the first layers of rope which gives its rated capacity.

https://www.youtube.com/watch?v=HXPqkh3F8qg the credits are hilarious.

Very clever indeed. I have been caught with winching and the extension ropes and straps leave the pulling capacity at its limit, so being able to trim it as shown is a plus for me. The device is expensive for what it ultimately is, however there has been a bit of thought and development time expended, so thats a direct cost.

16th December 2020, 09:16 PM

16th December 2020, 09:30 PM

Whoops, played it again, this time zoomy’d in on iPhoney little screen. Think that’s multicoloured nuffy MB unbeknown rope now not sheathing Philstar?

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PeeBee

16th December 2020, 09:33 PM

Does look a great piece of easy lightweight gear Philstar [emoji106][emoji106]
Did only briefly notice on Muddy’s kind Youtubey link that the blokes extension rope appeared to have protective sheathing every few metres (yanky yards :-) that he was matching up both ways back to itself before final lashing through?
Wondering if they’re just loose sheaths like our hook ends held in place or he’s somehow got them affixed properly at intervals along the extension rope?
They could just simply slide along I guess much like a ratchet strap sharper load edge sheath maybe?

Sent from my iPhone using Tapatalk

Mark, the various ways to rig this device are all done with clean rope, no sheaths. I didn't pick that up about the rope sheath, however did ask for a download, which he sent me of the various configs about 2 weeks ago. Its even possible to double rig this device like a capstan winch as an aux anchor, like say you wanted a second line hooked to the vehicle in case a single line was not going to quite get you there, - very interesting concept. I had to use a similar set-up getting out of my bush camp block when decending a steepish off slope graded clay hill. We rigged ropes on front and rear recovery points and back to tress, then the guys kept the tension on the ropes front and rear as I slowly decended, all the time inching into the high side bank. This device could also be used for that. I particularly like the simple extension rope shortening function as my ropes are all 40 and 50m long.

16th December 2020, 10:08 PM

Honestly do really like it Mate, thinking they’ve ingeniously supercharged rock climbing/abseiling lighter figure 8 type thingies?

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PeeBee

16th December 2020, 11:17 PM

Honestly do really like it Mate, thinking they’ve ingeniously supercharged rock climbing/abseiling lighter figure 8 type thingies?

Sent from my iPhone using Tapatalk
Have a play with it first and see if it fits the bill

MudRunnerTD

5th February 2021, 01:53 AM

Well this is just bloody average. I don't have the whole story but the bloke says a shackle did this. 8 must assume that they joined 2 straps together to increase length and snatched. Terrible idea, a Dampener would have helped. Glad none died. Imagine if it went the other way through a windscreen!!!

http://www.nissanpatrol.com.au/forums/images/imported/2021/02/65.jpg

http://www.nissanpatrol.com.au/forums/images/imported/2021/02/66.jpg

http://www.nissanpatrol.com.au/forums/images/imported/2021/02/67.jpg

http://www.nissanpatrol.com.au/forums/images/imported/2021/02/68.jpg

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rusty_nail

5th February 2021, 06:34 AM

Wowsers. That's a serious hit!

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MudRunnerTD

5th February 2021, 12:55 PM

Wowsers. That's a serious hit!

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what is actually pretty scary in that last pic is that Most of that Damage is from the Strap..... Not the shackle! Brutal! Imagine that hitting you!

5th February 2021, 08:16 PM

what is actually pretty scary in that last pic is that Most of that Damage is from the Strap..... Not the shackle! Brutal! Imagine that hitting you!

Do you mean the strap did the wider damage on the door?

Brutal impact and bloody lucky!

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MudRunnerTD

5th February 2021, 10:33 PM

Do you mean the strap did the wider damage on the door?

Brutal impact and bloody lucky!

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Yes mate. You can see where the shackle hit as an impact puncture but the massive spread of damage to both doors is all Strap. That is a Tough bit of door too!!!

PeeBee

20th February 2021, 02:14 PM

This finally arrive from the US whilst on shift. very nicely finished, now just have to practice using it to get the benefit.82917

21st February 2021, 06:32 AM

This chap seems to have some helpful videos found I’m learning on too folks:

https://youtu.be/s1h9whPOPn0

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PeeBee

21st February 2021, 01:06 PM

Good clear explanations and easily understood. Its really simple trig stuff when it comes down to it, 'triangulated ' forces or vectors, easily missed in the field under duress and when the operation appears to be nothing like the theory. Good find @MB

22nd February 2021, 11:52 AM

Here’s another interesting test from Robert Pepper on Snatch Blocks versus Rings:

https://youtu.be/rdlRRAbzCzA

Appears at the 20:00 mark that we should account for an approximate 5% efficiency loss for a Snatch Block & 10% efficiency loss for the Rings:

http://www.nissanpatrol.com.au/forums/images/imported/2021/02/157.jpg

He’s going to do some more tests soon to see further affects of mud etc....

http://www.nissanpatrol.com.au/forums/images/imported/2021/02/158.jpg

Efficiency variance seems to not be much of an issue to worry about in his opinion:

http://www.nissanpatrol.com.au/forums/images/imported/2021/02/159.jpg

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MudRunnerTD

15th August 2021, 10:02 AM

That's Mr Pepper. Very informative .

I only watched his bridle video few days ago ...

https://youtu.be/V13ARMYoAos

This is a Great Video about the Maths of using a Bridle to centralise the load across the chassis.

Fundamentally we need to consider the side load when winching from an angle. This video explains it quite well.

Using a single length bridle across the points rather that 2 3m straps to the hook. 1 6m strap with the hook around the middle that can slide.

The further away from the vehicle the centre of the bridle is the Les the angle and the less the side load is. A 6m bridle, so 3m each return, seems the best option.

Do yourself a favour and Watch the Video.

Thanks for the content Hodge!

3rd July 2022, 08:49 PM

Bought em, couldn’t trust my own monkey fist knots some years ago I think, lightweight and stored conveniently out of the way [emoji123][emoji736]

http://www.nissanpatrol.com.au/forums/images/imported/2022/07/27.jpg

Time wise, still have never utilised them?

Every Landcrab we pass by has sharp recovery points requiring old school Bows ?

http://www.nissanpatrol.com.au/forums/images/imported/2022/07/28.jpg

In all honesty, is it a nice to have connection but in reality Peoples trucks out there are non compatible? [emoji120]
They’re not in the way, will keep though for a rainy day [emoji848][emoji120][emoji120]

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MudRunnerTD

3rd July 2022, 10:40 PM

MB nice one mate. Yeah I have quite a few soft shackles now. Still like the ones I made as the strongest I have as they are the only ones made from 12mm rope. Over the gear stick for the storage win for sure.

I have a snatch ring which I have used a few times now and recently bought another through a big sale discount, when it turned up it is made for 12mm rope and is about 150mm across so a really good diameter too. Stoked.

I also grabbed an 18mm Kentic Rope which is snazzy. Not a big fan of snatching and in the GQ will always Winch cause 24Vforlife. But it could see some use in Cape Jaffa.

3rd July 2022, 10:47 PM

I’m confused Again Dazman [emoji120][emoji120]
As per above, where do I connect a soft bought shackle to the likes of any modern car with Aftermarket sharp as razors tow/recovery points? [emoji120][emoji120]

EDIT: Happy to RIP a Melbourne City sexy ‘D’ shackled colour coded bumper clean OFF its tinfoil chassis [emoji23]

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MudRunnerTD

3rd July 2022, 10:57 PM

I’m confused Again Dazman [emoji120][emoji120]
As per above, where do I connect a soft bought shackle to the likes of any modern car with Aftermarket sharp as razors tow/recovery points? [emoji120][emoji120]

Sent from my iPhone using Tapatalk

Yes this is a problem for sure. But let's consider in that recovery the soft shackle will be used at the anchor point, ie. The tree truck protector if the hook won't work or if the Double line pull is needed.

We don't need to over Engineer anything, and the steel gear still has a place for sure. The Soft shackle should be used wherever possible though bearing in mind sharp edges.

I recently also invested in a 50mm square hitch receiver specifically designed to take a soft shackle which I will run on the back of the62.

3rd July 2022, 11:02 PM

MudRunnerTD

3rd July 2022, 11:06 PM

I was under the impression that we could all throw away our old heavy gear and rely on soft shackles spruiked by so many here there and everywhere, not the case in my travels [emoji120][emoji120][emoji3590][emoji3590]

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Yeah we really are in an extended transition period mate, fast forward another 10 years and there will be very few recovery points with sharp edges. It's coming, we aren't there yet though. As I replace or update gear I am certainly making choices around my want to use Soft shackles.

3rd July 2022, 11:13 PM

Thank God, someone’s going to outlaw any vehicle bought pre 2022 [emoji23][emoji736]

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MudRunnerTD

3rd July 2022, 11:32 PM

Thank God, someone’s going to outlaw any vehicle bought pre 2022 [emoji23][emoji736]

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Bhahahaha. Mate if VicPol had there way every GQ would be crushed yesterday. Lol.