Mud-club
Chat & Social => The Bar - General Chat => Topic started by: dxmedia on November 03, 2009, 09:21:30
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cough - as the title says. I'm just wondering if anyone has any 'personal' views on recovery processes?
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:lol: :lol: :lol:
I read this before I saw Chris' post on the other thread..... now I understand :roll: :lol:
So....
Basic rules...
If you don't know how to use the kit, don't use it.
If you buy kit, make sure you learn how to use it. This might mean a formal course, or gaining advice from professionals.... and that isn't the bloke down the pub who says he's a professional :lol:
Make sure you buy proper kit. Not cheap shackles from your local car boot sale and a tow rope from Halfords.
If in doubt, STOP.
Start gently and build up the force slowly. Don't go at it like a bull in a china shop. (feel free to make your own innuendos up here!)
If a mistake is made (we are all, well most of us, human) make sure the vehicle in question is secure and the occupants are OK.
I'm sure there are plenty of other rules to be added......
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The most important piece of off roading equipment is the squishy grey thing between your ears. Think the recovery through and use common sense.
Don't allow onlookers to stand in front of you.
There should be a minimal number of people directly involved - you, the driver of the stuck vehicle, and a trusted spotter to watch for problems (eg vehicle being recovered is about to get dragged onto a bank that will tip it, tow rope is fraying). The driver of the recovery vehicle should be listening to the spotter and the stuck driver, nobody else.
Try to ensure that the vehicle doing the towing starts on firm ground (use a longer rope if you have to), that will enable them to gently pull you clear rather than having to do anything violent.
Only buy properly rated kit - there are a number of guides that will explain load ratings (usually cast/stamped on shackles, and on a stitched-on label on strops). Nothing sold in your local Halfords is suitable for off road recovery - they are selling for towing broken down vehicles on tarmac.
Look after your kit. Wash the mud off, let it dry properly, check for scuffs, frays, or any other damage. Dried mud getting into the fibres will do a lot of harm as it will act as an abrasive.
Don't use a chain, it has no give in it whatsoever. Even a dead strop has a little stretch in it.
Don't snatch with anything other than a kinetic rope.
Don't use a kinetic rope as anything other than a last resort.
Don't use a kinetic rope on anything that lacks proper recovery points, and inspect them thoroughly before attaching the rope. Any rust or weakness could see the shackle and a chunk of one or other vehicle flying through the air with enough force to kill or at least seriously injure.
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Safety always 1st place
Waffle boards are a very versatile and worthwhile addition to my recovery kit
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I suppose this is a topic that needs bringing out out in the open. It's late so I won't go to town but.
I usualy speak to the person I'm recovering and discuss how it's going to work.
I look for the easiest option first.
I try to use the minimum of kit, partly so I have something in reserve eg Hi-Lift on standby incase the winch fails.
I try to do it as gently as possible, only escalating if that fails.
So, tow it, winch it, yank it. In more or less that order and only when pushing, digging and changing tyre pressures have been ruled out.
Also worth mentioning. Unless you are an AA recovery agent the chances are you are not insured to carry out recovery. I'm pretty sure my insurance is void if I recover a venicle other tan my own with my winch, though it says nothing about any other sort of recovery. Make sure the person you recover underasrtands what liabilty you will accept before agreeing to tow.
Agree on your startergy. If you are recoving someone who does not underatnd what youe proposing to do and the risks involved, ask yoursefl if you really want to be doing this.
I'd say we had a responsibility to enure we work safely and don't make things worse than they already are, other than that there aren's so much rules and common sense and courtesy.
My 2 penneth. Let's see what others think. If we come to an agreement then perhaps we can call it a "code of conduct".
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Stand up, get out of ditch, go home, sleep it off, drink lots water, take paracetemol. :oops:
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go to tesco's buy a crate of beer and see how it goes :lol:
i mean use a rope :lol: ;)
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The first and most important step to any recovery job is to get the camera out !
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you forgot the point and laugh bit, and the cost...crate of beer usually suffices for me if someone has done something stupid.
before doing any type of recovery, get people out of any danger, work out an estimated pull (the force in tonnes would be sufficient and dont forget about a 25% safety factor), plan the recovery, (one of the most important bits), work out what you are going to use and where you are going to attach the said pieces of equipment, make sure all the kit you use and the recovery points it is attached are adequate and up to the job of applying an extricating force to, then start.
everyone in the 4x4 community will have an opinion on how a recovery should be done. sometimes it will pay off to stop and think about what someone is saying as they may have a different view point on the situation.
i find that the best way to get someone out is the way they went into the obstacle. usually because they have become immobile because of something in front of them. but then they may have dropped into a hole nose first and got stuck. if the back end of the vehicle being recovered is at a steep angle, alot of the force from the recovery will be taken up dragging the back end of the motor down. if thats the case then a pull from the front with someone in driving may get them rolling quicker.
stand back and survey the situation, as said before dont rush into anything, and if you see something going wrong or you deem to be unsafe then stop the recovery, dont feel shy or embarassed, better to be safe than sorry.
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call in the REME
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before doing any type of recovery, get people out of any danger, work out an estimated pull (the force in tonnes would be sufficient and dont forget about a 25% safety factor)
I would be interested to know how many people can sensibly do that and put a number to it? Other than when your winch reaches its limit how do you estimate the force on it?
Out of interest I am currently operating a winch that can pull 350 tonnes - that would get it out!
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the easiest way to do it, is thus:
establish the type of ground you are in, then apply the appropriate 'ground factor' (GF).
hard standing = 25
grass = 7
hard wet sand = 6
soft wet sand
or gravel = 5
loose dry sand = 4
light mud
or shingle = 3
deep mud,
bog or clay = 2
then work out the weight of the vehicle, round up to the nearest tonne, so a rangie or a disco would work out to around 3 tonne.
last thing is to work out the degree of the slope that you will be pulling the vehicle up. for this example i will put it at 25 degrees.
once you have all this information you need to use it to find the rolling resistance (RR), gradient resistance (GR), damage resistance (DR) and a safety factor (SF).
use these simple equations: RR = WOV/GF
GR = WOV x DEGREE of SLOPE
60
DR = two locked wheels = 1/3 weight of vehicle, four locked wheels = 2/3 weight of vehicle
SF = RR + GR + DR
4
once you have all these worked out, add them all together (RR + GR + DR + SF) and this will give you the estimated pull (EP) required to extricate a vehicle safely.
then in tonnes, work out the maximum cut out of the winch (WCO) being used so you can work out the mechanical advantage (MA).
MA = EP
WCO
so, a disco stuck in deep mud with an incline of 30 degrees with no damage works out something like this:
RR = WOV/GF = 3t / 2 = 1.5t
GR = WOV x DoS = 3t x 30 = 1.5t
60 60
DR = none
SF = RR + GR + DR = 1.5t + 1.5t + 0t = 3t / 4 = 0.75 t
4 4
EP = RR + GR + DR + SF = 1.5t + 1.5t + 0t + 0.75t = 3.75t (round up to the nearest ton) = 4t
MA = EP = 4t = 1:1 or single line (if EP had been more than 4.3t it would have been 2:1 or a double line pull)
WCO 4.3t (4.3t average 9500lbs winch on the bottom layer of wire on the drum)
so, any questions?
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the easiest way to do it, is thus:
could have just linked to the full REME recovery manual instead
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i could of, that was off the top of my head.
(recovery mechanic by the way...)
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Chinnok - might be over kill and expensive, but will look good and have some really big bragging rights!
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Nice calcs there,
Now someone should stick them on a webwith a front end menu and iPhone app!
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Nice calcs there,
Now someone should stick them on a webwith a front end menu and iPhone app!
I did it for a PDA app couple year ago as an winching aid, can't find where the hell it is now, no reference on this laptop, never released it :( It was intended to be simplified for landrover use. Using vehicle weights for different selectable models (images) with user defined loading of those models, again simplifed as in no load, partial load, full load. Tried to keep the math away from user as much as possible and give guesstimated figures.
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Shame, how about a mobile web version? (provided they get reception where they winch)
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you could probably set up something with an excel typ program with the formulas entered in the right place so all you have to do is enter the vehicle weight, gradient and the damage.
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i could of, that was off the top of my head.
(recovery mechanic by the way...)
you want an A mec..normally better looking than a recy mech!
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in addition to it all talk through every move before you start so everybody knows what their role is and whats happening
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in addition to it all talk through every move before you start so everybody knows what their role is and whats happening
that comes under 'have a brew and smoke em if you got em'