Team-BHP - Recovery and Salvage techniques.. Post Here

Quote:

Originally Posted by tsk1979 (Post 948812)

the bungee rope stores energy which was used to pull out the struck hilux

But one question on "local canvas ropes" as suggested by DKG. There is no guarantee of quality etc., on these, and I am not sure they are made for off roading. I think cranes were mentioned somewhere, but what i f the rope is designed for light weights. Morover things are lifted smoothly in case of cranes.

Sadly as 4x4 accessories are not available freely in India and since as you correctly point out the need for every offroader to have it I thought a crane canvas belt rated for 5 tons should be useful. But only till someone can get the professional grade belts, like what I have posted. The elasticity is the key in this. They work brilliantly and as you said they store energy more efficiently allowing for a smooth transfer

The idea for this came when I noticed identical material in a crane supplies store. Since the material handles heavy loading thought it would work here too. If they can stitch loops that hold 5 tons then surely it can withstand loads in a offroad pull

Quote:

Originally Posted by DKG (Post 948788)

...have driven enough in soft desert sand (which is one of the worst for recovery) and this technique is widely used....

debatable, DKG :). I think very wet and sticky slush of clay-like soil would be tougher terrain to do recovery from.

The clay-slush would make it additionally difficult to attach ropes (in the absence of easily accessible tow hooks in the stuck vehicle)

Arka has a valid point in terms of using recovery techiques safely.

Quote:

Originally Posted by ex670c (Post 948769)

...Recovery Techniques is not about making tall claims, neither is it about brute strength.
Its applying the minimum external force required, through proper equipment, in the shortest time possible, to SAFELY recover a vehicle.....

that is very crisply put, Arka :thumbs up

.

Quote:

Originally Posted by Blue Thunder (Post 948869)

I think very wet and sticky slush of clay-like soil would be tougher terrain to do recovery from.

You are quoting out of context. I said the snatch technique is very handy in soft sand. You are debating whether its worse than slush. That was never an assertion :)

Safety in everything we do is paramount, that is never questioned. The discussion was on the snatch technique. That is not necessarily unsafe!

PS The snatch technique works very well in slush and clay too :)

If you study what I have said as a subject of physics what this technique does is it augments the energy provided by traction plus uses potential energy from momentum to snatch the vehicle out.

Therefore when traction is weak its momentum which works and that gets transfered only through a snatch pull

Quote:

Originally Posted by DKG (Post 948881)

You are quoting out of context....

Again, debatable !!!

Quote:

Originally Posted by DKG (Post 948881)

...Safety in everything we do is paramount, that is never questioned. The discussion was on the snatch technique. That is not necessarily unsafe!

Quite true, DKG, but there are certain additional safety points to be taken care of, when using this technique as compared to the standard tow rope/chain (due to the elasticity). I think this is what Arka was trying to highlight.

(an example)
**********************************
One may be under the false belief that there may not be much damage in case the elastic rope breaks since it is elastic. But this is not the case, the damage from the backlash can be very serious : even life-threatening. This is the reason why it is suggested to use some thick rug/mat on the rope so that the backlash in case of failure is restricted.
************************************

Since this is a public forum (with people of varied experiences/age), it becomes imperative on us to highlight all such aspects, and not assume that the others who are reading may already be aware of it.

Quote:

Originally Posted by DKG (Post 948881)

...PS The snatch technique works very well in slush and clay too :)
...

No one is questioning the efficacy of this method, DKG :), it is just that the additional safety aspects need to be highlighted well, so that a person who is going to try out this technique for the first time is suitably prepared.

.

so the real question is that can this technique snap the 5 ton rated crane cable? If so, then its pretty unsafe.
At our village recovery of tractor is done by placing wooden planks under the wheels. Shouldn't that be tried first before using towing.
IMHO towing and winching should be the last option. Before that things like removing air from tires, placing rocks under wheel, placing planks under wheel etc., should be tried.

Quote:

Originally Posted by tsk1979 (Post 948898)

IMHO towing and winching should be the last option. Before that things like removing air from tires, placing rocks under wheel, placing planks under wheel etc., should be tried.

Spot on! Towing and winching is the last option when all else fails.

Also this crane belt thing is yet to be tested. I merely suggested it as a possibility since the loads in that industry are as if not more severe as in a tow situation.

Blue Thunder the discussion started with Arka asserting the snatch technique is unsafe and not recommended. I through experience know it to not be unsafe. As regards additional precautions, well, more the merrier :)

Quote:

Originally Posted by tsk1979 (Post 948898)

so the real question is that can this technique snap the 5 ton rated crane cable? If so, then its pretty unsafe....

if used properly, this technique will not snap the 5-ton rated crane cable (assuming that you are trying to pull out a sub-2-ton 4x4).

But one question : the crane cable that you are referring to : is it elastic? I dont think so. If it is not elastic, one need not worry so much about the backlash effect (in case of the cable failure).

.

Quote:

Originally Posted by married2speed (Post 948913)

aren't we getting confused here between tools and technique?

The snatch technique I spoke of inherently uses the canvas type tow rope I listed, as it has a built in elasticity. Arka questioned this technique. I disagreed with his concerns that this was inherently unsafe and not recommendable. My experience has shown me otherwise, hence my stand

Quote:

Originally Posted by Blue Thunder (Post 948916)

if used properly, this technique will not snap the 5-ton rated crane cable (assuming that you are trying to pull out a sub-2-ton 4x4).

agreed

Quote:

But one question : the crane cable that you are referring to : is it elastic?

Its a canvas belt I've seen in crane supplies stores identical to the professional grade belt I have posted. As the canvas belt I have is elastic I am assuming this is too

That said I could be totally wrong in assuming the crane canvas built will offer similar performance. This is yet to be tested. A prof. grade tow rope would be the best option

Quote:

Originally Posted by DKG (Post 948932)

The snatch technique I spoke of inherently uses the canvas type tow rope I listed, as it has a built in elasticity. Arka questioned this technique.

I never questioned the snatch technique, but the manner in which you presented it.

I was taught and also learnt that this techniques is THE MOST DANGEROUS recovery technique and it is the MOST ADVANCED recovery technique and the fastest recovery technique.

i) it is the most advanced because of the calculations (resistance/pull)involved.
A significantly lighter vehicle can easily pull out a much heavier vehicle.
The availability of a RATED Kinetic Energy Strap.

ii) Its Dangerous because if the calculations are wrong we will have parts/shackles/bumpers or whole vehicles flying.
Availability and identification of equipment (rating/elasticity/breaking strength)

iii) It is fast An MM540XD can easily pull out a TLC 100 series bogged upto it chassis.The entire recovery exercise will take few minutes.

Regards,

Arka

Quote:

Originally Posted by DKG (Post 948881)

You are quoting out of context. I said the snatch technique is very handy in soft sand. You are debating whether its worse than slush. That was never an assertion :)

Quote:

Originally Posted by DKG (Post 948932)

The snatch technique I spoke of inherently uses the canvas type tow rope I listed, as it has a built in elasticity.

Technique is everything (almost). Firstly you have to attach the cable correctly. Second, learning if a "snatch" will help is often emperical. I have seen tow truck drivers (on highways) drag 20 ft. container trailers out of ditches.

BTW, Arka, why do you take umbrage in everything DKG says? Chill a little.

Quote:

Originally Posted by married2speed (Post 948913)

aren't we getting confused here between tools and technique? DKG is referring to the tool while arka what you're saying is about the technique.
In my opinion both of you are correct. The right tool without the right technique is no good and vice-versa.

Please correct me if I'm wrong
M2S

Each type of cable/tape/rope performs differently under
1) Heat
2) Water/Humidity
3) Stress.

The Snatch Technique can be performed WITH ONLY RATED SNATCH STRAPS. These are not canvas or Nylon webbing or tape. These are not available in India otherwise I would have suggested the same.

I have seen the effect of tugging/jerking/snatching/shock loading with
1) ISW Ropes - Damages both Anchor/mounts
2) Polypropylene (Garfil) ropes - Breaks
3) Nylon Straps - Tears/Damages Mounting/Pulls back the towing vehicle)

Regards,

Arka