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australia:4wd_winching

4WD and electric winching recovery

Introduction

  • it is inevitable for many 4WD owners who go off road for the challenge that they will get stuck and need winching
  • many 4WD owners who enjoy these challenges will opt for a winch unless they travel in convoys in which case someone else will generally have a winch on their vehicle
  • most winches for 4WDs have around 4000-5000kg pulling power, using a double line winch set up will effectively double the pulling power
    • winching a 2700kg 4WD on a flat gravel road with locked brakes needs about 1900kg peak pull and probably around 1600kg average pull
    • winching a 2700kg 4WD up a 20deg gravel road needs about 1400kg peak pull and probably around 1200kg average pull
  • winching is DANGEROUS (although less so than snatch recoveries) ensure safety measures are in place
    • avoid submerging in water and after river crossings always take the line out to inspect and dry
    • line must be re-wound onto winch under tension correctly
    • wear gloves - especially if using steel cable winches
    • do NOT operate winch when intoxicated with alcohol or drugs
    • winch rope itself should not be used as a tow rope
    • ensure remote for winch is NOT connected whilst setting up rigging
    • ensure rope/cable is not worn, frayed, kinked or damaged
    • do not hook the winch rope back onto itself - use a choker or sling instead
    • don't join ropes with knots as these weaken - there are far safer methods
    • open the vehicle bonnet for added protection to windscreen
    • operate winch 30secs on and 30secs off to reduce draining battery (with vehicle running to keep battery charged)
    • never engage or disengage the winch clutch if the winch rope is under tension or if the winch drum is turning
    • keep hands and loose clothing clear of the winch rope and fairlead rollers during winching
    • the winch rope fastener on the winch will not support heavy loads therefore, never winch when there are less than 5 wraps of winch rope on the winch drum or a full drum width coverage when a synthetic rope is used
    • NEVER attach to a tow ball - this may become a lethal missile
    • avoid unnecessary heavy objects in the line such as metal shackles
    • use line dampeners - one in the middle and one near the far end of the line
    • all people well out of the line of fire if a line breaks
    • good communication strategy with the person in control of the winch - ONLY ONE PERSON should be in control of the winch
    • ensure the driver is the LAST person out and the first person into the stranded vehicle - don't want passengers in an out of control vehicle rolling down a hill!
    • don't straddle the line
    • ensure the anchor is safe - do not attach to a dead tree (it may be hollow and fall) or a small tree (it may be uprooted) and attach as low as possible to minimise chance of uprooting the tree
    • once the line has been placed under some tension, CHECK ALL PARTS of the line BEFORE commencing winching
    • where possible don't attach the dual line back to the recovery vehicle with the winch - use a tree instead to reduce stress on the vehicle chassis (this won't help though if your winch vehicle is the stuck vehicle)
    • do NOT reverse the winch vehicle as you winch to recover another vehicle as the forces may cause catastrophic damage and injury - preferably no one should be inside the winch vehicle unless needed to apply the foot brake (automatics should not be put in Park - preferably use a ground anchor instead)!
    • where possible winch line should be coming straight out of the winch when winching - extreme angles will result in winch line piling up unevenly on the winch
  • BEFORE winching ensure the resistance is reduced as much as possible using other recovery tools such as:
    • shovels to remove soil/sand in front of wheels
    • MaxTrax board to provide a ramp where appropriate
  • Winch line may BREAK without warning
    • this will usually result in a potentially lethal missile heading back towards the stranded vehicle (or to the side of it) at head or chest height with enough force to cause an immediately fatal blow
    • if using two pulleys in a two directional pull, the whole area between the pulleys and the winch and the stranded vehicle and behind the winch area is a very high danger area
    • this may result in the stranded vehicle rolling down a hill out of control
  • the pulling load capacity of a winch REDUCES the more line is on the winch itself
    • generally pull most of the line out until the minimum required to fasten it to the winch remains

Gear required

  • rated recovery point for dual line winching
  • winch with remote control
  • tree protector strap
  • optional deadman - this is great for sand anchoring or tree trunk protection
  • UHF radios are very handy to communicate starting and stopping the winch
    • alternatively, learn the hand signals for winch in / out / stop
  • line dampeners for safety (but can use a range of camping items for this purpose such as towels etc)
  • optional X-Lock to allow shortening of a line
  • PLUS one of the two options below

option 1: old school steel cable winch

pros

  • steel cable is much less susceptible to sharp objects, and abrasion issues, dirt, and sand

cons

  • very heavy with need to use a very heavy and large snatch block
  • susceptible to rusting
  • more dangerous as more heavy missiles if it breaks under tension

specific gear needed

  • steel cable usually with large metal hook which will connect either to your tree trunk protector strap or to your recovery point if using dual line winching
  • snatch block

option 2: modern synthetic rope winch

pros

  • much lighter and more compact
  • potentially safer as less heavy missiles if it breaks
  • allows use of much lighter and more compact winch rings instead of a snatch block
    • much better than heavy, difficult to use snatch blocks which are not well suited to Dyneema rope but designed for steel rope and steel snatch blocks require use of a hard shackle NOT a soft shackle which adds to weight and missile danger. Winch rings have a slightly lower efficiency of around 92.5% giving around 1.7-1.8:1 MA in a 2:1 system under 1500-2000kg loads compared to just over 95% or 1.8:1 for some snatch blocks. For comparison, using a bow shackle as a pulley gives around 1.45:1 MA and is a lot less efficient and more dangerous 1)

cons

  • rope is susceptible to sharp edges and abrasion wear:
    • must be kept clean - especially sand particles can cause tears under high tension
    • avoid allowing it to scrape along the ground - may need a higher anchor point
    • MUST not be used on gear with sharp edges
  • rope and soft shackles should avoid being exposed to prolonged UV light for months
  • soft shackles should not be kept attached to vehicle as exposed to abrasion, dirt and UV
  • may need a metal bow shackle to attach to recovery point if it is not designed for soft shackles
  • can be more expensive

specific gear needed

  • soft shackles
  • metal bow shackle if using dual line winch to a recovery point that is too sharp for use with synthetic ropes
  • a winch ring for synthetic ropes (consider a 2nd one for two pulley directional pulls via a 2nd vehicle)
    • factors to consider in choosing a winch ring to buy:
      • sheave should be curved not V-shaped, kept smooth, free of burrs and gouges
      • soft shackle should have any protective sheath removed as this adds friction
      • rope manufacturers recommend a D/d ratio (inner diameter of pulley where rope sits / rope diameter) of the pulley to be 8:1 for braided ropes and 10:1 for twisted/plaited ropes for commercial use however 4WD infrequent use can get away with 5:1 or more, thus for 12mm rope you need sheave diameter of at least 60mm and the greater the diameter, the less stress on the rope
        • Factor 55 (~600g) has diameter of only 55mm, George4x4 (~400g) has diameter of 66mm while the Sabre has a diameter of 94mm but weighs almost 900g
      • the pulley bend radius (the amount the soft shackle curve flattens out in the pulley) should be relatively wide and CURVED not flat (otherwise you end up with a 90deg bend at the edge)
        • Factor 55 pulleys have a better shackle friendly designed but their pulley diameters are relatively small for their size
      • the flange holding the rope in should be relatively deep
        • George4x4 pulley has limited flange depth of 15mm which may be more problematic although very unlikely
        • Factor 55 pulleys have a nice deep flange depth of 33mm supplemented with retention teeth
      • rope should sit in centre and not be able to move laterally hence the flange should be U-shaped rather than square or V-shaped (Factor 55 and George4x4 pulleys are great in this respect)
      • should have low surface friction
        • avoid pulleys with embossings on the outside of the flange where the shackle may touch eg. CampBoss is poor, Factor 55, Sabre are good
      • pulley should display rope diameters and working load limit (nearly all have a WLL of 8000kg or more which should suffice most 4WD needs)
      • good options are:
  • Dyneema rope (generally have up to 30m line) eg Runva
  • optional splicing tool for Dyneema rope eg. Factor 55

5:1 winching with a pair of Fiddle Blocks for synthetic ropes and soft shackles

  • these are best for recovering heavier vehicles in the 4500-8000kg GVM range when you only have a 4500kg winch
  • too expensive and bulky for smaller 4WDs
  • you need TWO Fiddle Blocks
  • the 50-70m of synthetic rope which must be 10-14mm and have a small soft eye at the end capable of being threaded through the block (not a hook or thimble)
  • you will need two soft shackles to anchor each block and a 3rd smaller soft shackle can be used to terminate the line onto the other end of one block
  • you will also need one tree trunk protector as the anchor
  • your line from your winch goes around the two rear ones of the main anchored Fiddle Block then back to the vehicle where the 2nd Fiddle Block is anchored and around the two rear pulleys then back to the 1st block's front pulley then back to the vehicle's Block's front pulley then the line terminates attached to the 1st block giving a total of 5 lines and thus theoretical 5:1 MA
    • it is slightly modified when using a 2nd vehicle's winch as the winch line first goes around the two rear pulleys of the block attached to your vehicle and thence in a similar manner to the above.
  • can also be used as a simple 2:1 snatch block

reverse winching

  • if you don't have a second vehicle or a high-lift jack to use as a winch, you can use your winch to pull you backwards in some circumstances.
  • reverse winching a 2700kg 4WD on slight rear incline gravel using a single line on winch going back to a rear double line rig - winch peak 1300kg, avg 1000kg, force backwards peak 1600kg, avg 1300kg which compares with the force required to do the same rear tow but with a second vehicle towing it backwards and this required peak 350kg and avg 250kg force and much less time!
    • reverse winching in effect will only give you a rear pull force of winch capacity load / 5 so a 4t winch will allow around 850kg which will allow winching up a 10deg hill but is no better than using a high lift jack winch even without a dual line pull
  • gear needed
    • at least 4 winch pulleys (one for main redirect from winch, another from a side tree redirect to get behind the vehicle, and another on 1st anchor behind vehicle and the 4th at rear of vehicle to create a dual line rig at rear)
      • the side redirect does not take much tension so in an emergency you could use a hard shackle instead of a pulley but it will be half as efficient and may weaken the rope
    • at least 30m winch extension rope
    • tree trunk protectors x 3-4
    • soft shackles x 2
australia/4wd_winching.txt · Last modified: 2023/01/19 22:28 by gary1

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