Training Wins and Fails

[AV8]

Just thought I'd post some youtube videos, which I'm sure everyone has seen before just as a refresher of what to do or not do in gearing up for club trips and Jambo.:smile-new:

Not everyone has Hunty's smart pills, so feel free to contribute, ask silly questions (that aren't asked/answered are more silly :shame:) or post comments on what you see that could assist us all when off road. Cheers


http://youtu.be/_XjXXt1qARk

Lessons here:



Diagonal Lines and inclines (steep or not) makes for a roll over.
Too tall: Unstable on accelerations/climbs and decelerations/descents 2:40
Springs/Shocks configuration: Too bouncy 2:40





Questions on Snatch Straps:



How does one choose which snatch straps to buy?
Could you hook it up the tow ball?
Could you hook it using the hitch pin?

[stevet]

Gravity!...:grief:............. Wins every time......:smile-new:....Think I was awarded the first bugger award cup some time ago...:grief:.............

[Steve F]

A lot if it is just use your judgement, or if it isn't very good use someone elses and know when to just stop ;) A lot of those were either poor judgement or just keeping the foot in when stopping and regathering your thoughts on the way to tackle the obstacle would have meant no video of you on youtube rolling your Jeep. Of course sometimes, no matter what you do, she's going over :(

And for some advice, down hill, when you drop off a step etc, it's important to keep driving. It's instinctive to step on the brakes as you go over but the momentum of dropping off a step whilst going down hill in a short wheelbase can end up in tears :)

Cheers
Steve

[Steve F]

Just watched the whole video and the last one is a great example of where just driving it (instead of braking) may have saved it :)

Cheers
Steve

[Dru]

Not sure I should have watched that.

[AV8]

Upgrading the winch cable. Plasma Vs Dyneema, which one?

Plasma Vs Dyneema
Plasma™ was the first fibre rope used to replace steel wire ropes on 4 x 4 winches in Australia and overseas. This small but nonetheless important revolution had its genesis in a small Western Australian company called Jeyco.
Jeyco specialises in the supply of high quality marine mooring and towing equipment and had already established the bone-fides of Plasma™ rope in the extremely harsh world of maritime towage. Plasma™ ropes had been used to protect the large and expensive polyester towlines used by the various tug operators around Australia. Plasma™ had proven to be an extremely hardy and robust rope, able to withstand the harsh rigours of the marine towage environment and overcome the massive abrasion damage which previously limited the towline to a lifetime of reduced efficiency.
By using Plasma™ Rope as a sacrificial tail on the end of the towrope the Plasma™ would be passed up to the larger vessel under tow and it would be the Plasma™ that would pass through the fairlead in the ship’s hull to be connected to the bollards on deck. These fairleads are typically in very poor condition with corrosion and damage from wire ropes, they would normally destroy a towrope in a short period of time. Since the introduction of these Plasma™ tails towline life has increased 3-4 times previous benchmarks. The Plasma™ itself has lasted up to 4-5 times longer than the previous rope in this application.
Having established that Plasma™ rope was a very tough rope Jeyco embarked on a mission to replace steel wire ropes in many applications where Plasma™ could either improve efficiency or safety. One of the first areas they looked at was winching applications as these tend to be highly abrasive to ropes and dangerous to humans.
During this time Jeyco had worked with the manufacturer, Puget Sound Ropes of Seattle to fully understand the properties of this new “wonder rope” as it was starting to be called by various people who had used the product. At this time and during subsequent testing Jeyco realised that the rope stored very little kinetic energy and as it was of a low density (light weight) there was little or no snap back or re-coil when the rope broke under tension. This made the rope very safe to use, and coupled with the high abrasion resistance and a higher than wire rope breaking strain it was also a very desirable combination of properties for a rope in winching situations.
OK I hear you saying, you have heard all of this before. I have taken you down this path to get to where we are now, that is accepting this rope for what it is…bloody brilliant, (to steal a line from JK Rowling). What I would like to show now is just why Plasma™ is so good at what it does.
One of the reasons for wanting to continue the education process about Plasma™ is so that people are armed with all of the information. We live in a competitive world and there will undoubtedly be imitators, some good, some not so good. So, just why is Plasma™ so good? And is it better than the other ropes on the market? To answer this question we need to look in detail at the rope in terms of the raw materials that go on to make up the various ropes and the methods of manufacture of those ropes.
For the types of applications we are discussing here, namely winching for 4x4 vehicles no fibre type other than HMPE or LCP should considered and there are very good reasons for that statement. OK, here we go again with techno-babble, what the hell is HMPE and LCP you say.
Well perhaps I should start by giving a very short history of fibre rope. ;
The first recorded fibre ropes appeared about 5-6000 years ago in Egypt
In 1930 the first synthetic fibre Nylon was invented, since then there have been some half a million combinations of fibre type and construction developed for a myriad of uses. The most common fibres used in rope manufacture are Polypropylene (Pp), Polyethylene (Pe), nylon (Pa), Polyester (Pes), aramid (Kevlar* Twaron* Technora*) HMPE (High Molecular Weight PolyEthylene) , Liquid Crystal Polymers (LCP) and blends of these fibres.
Now why are HMPE and LCP fibres the only ones that should be used for 4x4 winching? Pp and Pe ropes are simply not strong enough and would require ropes of around 18-24mm diameter to replace the 8mm steel wire ropes typically used on most 4x4 winches. Nylon and polyester stretch too much such that the recoil would injure or kill anyone with in range of the rope. Aramid fibres whilst having the strength, suffer enormously from abrasion and bending fatigue, so much so that they would be considered extremely risky in this sort of application.
HMPE ropes on the other hand demonstrate the right amount of strength so that they can replace steel wire rope on a size for size basis, and offer almost no recoil. They also have very good abrasion resistance and excellent bending fatigue resistance, some superior to wire rope in fact. Now the trick here is that there are two types of HMPE fibre, one is the raw material for Plasma™ and it is called Spectra*. The other is a product called Dyneema*.
(LCP fibre ropes are excellent for a number of applications including 4x4 winching, however they are around 40% more expensive than Plasma so we have not considered them in this article).
While these two HMPE products are virtually identical in many ways and have almost identical strength values, they can however perform somewhat differently in use, depending upon the application. Both fibre types have two grades, Spectra* 900 and Spectra* 1000 compares to Dyneema* SK-60 and SK-75. It is worth mentioning at this point that Plasma is not simply a high grade of Spectra, it is a fibre that has undergone Puget Sound Rope’s patented re-crystallisation process.
This process basically sees the fibre drawn down to increase tensile strength in a manner similar to that used in the steel industry to increase strength. Without going into too much detail it basically works like this; multiple filaments of Spectra 900 are twisted into a yarn and super heated then drawn through a series of baths to produce the finished high strength fibre. This process refines the molecular structure such that almost 98% of the molecules are parallel to each other thereby increasing strength substantially. This is the fibre at the heart of Plasma rope’s strength, and this is where things get really interesting.
To compete on a strength basis with Plasma many of the ropes made from Dyneema have to in some way, enhance their strength, but as the Re-Crystallisation process is patented to Puget Sound Ropes these rope makers have to use other methods to increase the base strength of their ropes. One of the most popular methods is to make a complete rope then subject it to high heat and load to basically stretch the rope in an effort to draw the fibres. This process does indeed increase rope strength, but at a cost as it is actually fatiguing the ropes. Flex fatigue figures for Plasma are far superior to those of ropes made in this manner.
There is one other large difference that exists between the two fibre types and it translates across the grades as well. This big difference is in the size of the filaments (the diameter), a filament of Spectra is about ten times the cross sectional area of a filament of Dyneema. Now this adds up to better abrasion resistance, both internal and external. You all know about external abrasion damage and how it can destroy a rope, but internal abrasion damage is just as important. Perhaps it is important to realise that a rope is the most complex machine of all time, every part is a moving part so therefore moves against another moving part. As you can imagine the abrasion going on inside the rope is always there and is one of the major forms of rope deterioration.
All of that extra material in the Spectra filament increases the surface bearing area thereby reducing inter-filament pressures with an attendant reduction in internal abrasion damage. Test results from yarn on yarn abrasion tests* show that Spectra based fibres can have up to 287% longer life than Dyneema fibres. Recent studies^ into the behaviour and life of ropes used in marine towage applications indicate that Dyneema ropes suffer from strength degradation at a much faster than Plasma ropes. Certainly when compared to tested results of Plasma ropes in similar applications, Plasma outperforms Dyneema.
The same can of course be said for the external fibres of the rope body, the increase in surface area reduces the effect of abrasion and therefore increases rope life. The larger size just makes them a bit tougher, and for the sort of work done by a 4x4 winch, toughness is a paramount quality.
During the course of a research program into the life of ropes in towage operations in the US, it was discovered that ropes made from Dyneema can suffer from drum compression damage, that is damage caused to the rope while it is stored on the winch drum. This is basically a fatigue mechanism that sees the rope strength degrade over time from being stored on a winch drum. This would appear to diminish the effectiveness of these types of ropes in 4x4 winching applications. Compression testing results indicate that Plasma would have a 30% longer life in these sorts of applications.
One other thing to be aware of is the method of determining rope strength. Most ropes made from Dyneema adopt the European or ISO standards method which quotes the theoretical breaking strain of a rope in the un-spliced condition, whereas all Plasma ropes breaking strengths quoted are for completed ropes fully spliced. A splice can reduce the strength of a rope by 10%.

[AV8]

SNATCH RECOVERY FOR BEGINNERS AND SINNERS ALIKE - Copy and paste from the net

The most important things to note with snatch recovery is that all recovery points are strong. Your strap should be the weak link, not the potential missile it's attached to. They do break, will break, and are supposed to break. Around $100 for probably your most important and most used piece of 4wdriving equipment is nothing IMO.


The recovery vehicle should merely be providing a tug to provide the momentum necessary for the stuck vehicle to gain motion. The elasticity and 2m of slack will dampen the shock loading on the vehicles and recovery points.


The numbers written or stamped, etc on recovery equipment is its BREAKING STRENGTH unless preceded by the letters WLL or SWL. The Working Load Limit or Safe Working Load is a strictly regulated standard denoting the Breaking Strength divided by a Safety Factor of 6.
In other words, a SWL 3.25t bow shackle has a Breaking Strength of 19.5t (approx 39000lbs). However a typical snatch strap has a breaking strength of 8000kgs (approx 16000lbs). Were it to be used in a regulated workplace it's SWL or WLL would be around 1300kg (2600lb).


NEVER join straps together with shackles, only use strong recovery points, stand well clear, establish a clear and concise communication method (horn, two-way radio, ect), use only enough power necessary, never panic.
And always practice somewhere in a controlled environment first. A campsite or driveway at home with a mate maybe. Same applies to all your equipment, no good trying to learn how to use it when you need to know how to use it.


I've been involved in many snatch recoveries and have broken straps. It's no big deal. I'd sooner a strap fail than a shackle, etc. After a while they will lose their elasticity, like a spring will, and eventually break or require replacement.
Every vehicle in your convoy should be carrying a snatch strap as the very minimum piece of essential recovery gear, so spares should be available.
I have tied a new eye on a broken strap, this is their most common weak point due to stitching failure, grit in the stitching, etc. I wouldn't tie it mid-length though as breakage here would indicate that the straps passed its used-by date. Broken snatch straps make great tow ropes, and emergency winch extension straps if after using all your straps you're still 5m short of a tree.

- Never use the tow hitch pin, it will bend. It could come flying off or just get stuck there in the hitch.

- Never use a tow ball to hook your straps to : Flying tow ball kills

- Buy/use rated snatch straps 2x-3x GVM

- Never join 2 straps together with a shackle or projectile. Use a rolled up old magazine.

- Use rated recovery points on the vehicle, not your tie down point not the axle or any part of the vehicle body

- Choose shackles SWL/WLL 3/4 T or more ( safety factor 6x-7x )


I stand corrected, so please comment.

[AV8]

More inclined, diagonal, holes, too tall springy action.

As Steve said, sometimes you have to floor it a bit when going into a hole/ledge downhill and use good judgement and be ever ready to reverse back immediately upon recognizance of the impending rollover when traveling uphill. Easier said than done of course:worked_till_5am::worked_till_5am:

Better yet, realize your capabilities and operating the man/machine/environment envelope. Chook tracks are fine. I'm always there..... ;)


http://youtu.be/omktDSNtcrA

[stevet]

Please also include the use of a dampener when ever you use/do a snatch recovery........... An essential piece of recovery gear for every kit............ Ideal for winch usage as well.................

[AV8]

Dampener, definitely.

Also choose your anchor wisely. Big, strong, living tree is a good one and always use a tree trunk protector.

Skinny, dead, rotting gum tree = Bad. (as seen at Widow Maker, Jambo '12)

Getting snatched off your axle or Jeep body = Bad (Plenty on youtube)

[AV8]

More roll overs. What would you do different?

Slam on the brakes?
Disable ABS?
Roll back as straight as practicable?
Prepare the vehicle with muddies in the first place? No place for all terrains 70/30 here..


http://www.youtube.com/watch?v=4z40E16O5Ew&sns=em

[redrubi]

More roll overs. What would you do different?


http://www.youtube.com/watch?v=4z40E16O5Ew&sns=em

That looks like the hill at the back of Rydal Showground!!

[AV8]

I think you may be right. Sure looks like it.

Water Crossing tip. I've taken my snorkel off because I don't like the looks of it and don't plan to go swimming with the truck neither. So, a Safari WJ Snorkel is avlbl for purchase.

http://www.youtube.com/watch?v=wNtJNuhIf4I&sns=em

[AV8]

Self recovery at 5:00

Learn how to use the Hitch Master

http://youtu.be/FsNaTZY3xXs