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Trailblazers and Envoys Offroad

Vehicle Recovery

By: James Downing

Understanding the basics:

A lot of people make the mistake of just pulling out a winch line, wrapping it around a tree, and powering the winch in. No, no, no. That may get you unstuck, but it’s risky and can be dangerous. There are proper methods and proper steps that should be followed that can reduce the risks inherent to off road vehicle recovery. I’ll take you through the process step by step in the following article.

Before proceeding with any recovery steps or tactics, the basics need to be discussed. The most basic thing to understand is that any recovery process creates large loads through the equipment that is in the system (‘the system’ refers to any component in use during the recovery, including the vehicles and anchor points). An important thing to understand is the WLL, or working load limit, of the equipment. By understanding the loads that the system can possibly experience, and exceeding those limits with the strength of the components in the system, you increase your safety factor. A safety factor is the breaking strength of the weakest component of the system, divided by the force being exerted on that component. A high safety factor is desired to ensure that no breakage can occur.

All good recovery equipment has WLLs labeled on them, or at least on their packaging. Some components are labeled in tons, some in kilograms, and some in pounds. Make sure you know the conversions between the units and understand your weakest link. You often want to design your system so the weakest link is the pulling mechanism (you or a motor). If your pulling component isn’t the weakest link, it is actually possible to fail a component in the system. The weakest component in the system is known as the ‘fuse’.

It’s important to understand how the forces transfer, not only through the recovery equipment, but also through the vehicle. Make sure the recovery points on the vehicle can withstand the forces involved in a recovery situation, and that they can transmit the forces to the frame. Even then, make sure you understand where the stuck-forces are coming from. If you have a vertical rock face in front of one of your tires, a recovery force could end up bending your tie-rod before moving the vehicle.

It’s also important to understand the three main categories of recovery.

  • Static – not putting impulse loads on the system: winching
  • Dynamic – recovery by momentum: yanker rope, snatch strap
  • Passive – use of traction aids, not inducing horizontal loads on the vehicle

A static recovery loads the recovering system without any stretching component. The recovery force is derived from a positive displacement element, such as a winch, or hand ratchet. Dynamic elements, such as ‘snatch’ straps, should not be used in a static recovery unless it is a last resort.

A dynamic recovery can be useful for a quick recovery, provided you have a second vehicle present. The recovery force is derived from the other vehicle’s momentum. If a dynamic strap is not used in this type of recovery, extreme damage can result.

A passive recovery does not utilize horizontal forces at all to recover the vehicle. The recovery is performed by simply increasing the wheel traction through various methods.

These three methods will be covered in depth on the coming pages.

Lastly… whenever a vehicle gets stuck or needs aid, remember Bill Burke’s 3 Ps before performing any recovery. Patience, Plan, then Practice. I’ve adapted the 3 Ps into the following four steps:

  • Assess
  • Plan
  • Envision
  • Perform

These steps and much more are covered on the following pages, so read on to the other articles listed below!

Stuck Assessment and Planning

Assessing the situation: As with any potentially hazardous situation, you always want to stop, take a breath, and slowly plan out your actions. The brutal truth is that most stuck situations are due to driver error – misreading the ground, or obstacle, or not understanding the vehicle limits. We all make mistakes here, often for [...]

Passive Recovery

Passive recoveries are sometimes the simplest way to recover a vehicle, and often overlooked. People are quick to grab a strap and hook up to another vehicle without understanding that a few shovels of dirt could allow the vehicle to drive out safely under it’s own power. There are a few passive methods, but almost [...]

Dynamic Recovery

A dynamic recovery derives its forces from the kinetic energy of a moving mass. Because of the method, it is important to ensure you are using an appropriate dynamic (stretchy) strap. Dynamic Recovery Straps: A dynamic recovery can be a simple method, provided that you have a second vehicle present. Dynamic recoveries derive the recovering [...]

Static Recovery

A static recovery derives the recovering force by steadily decreasing the length of the recovering system. Because this method is slower, it can provide much increased control and safety over a dynamic recovery. Anchor Points: Because of the recovery process here, the system needs an anchor. This can be a tree, a rock, or a [...]

Tools and Equipment

A proper recovery kit will depend on which recoveries you will be performing. Passive Recovery: Jack Hi-Lift X-Jack Bottle jack Ladder Bridging Sand D-handle shovel Carpet strips Tire chains Lift-mate Larger jack base Dynamic Recovery: Another vehicle Proper anchor points on both vehicles Properly sized dynamic strap Static Hi-Lift Recovery: Hi-Lift Off road (winching) kit [...]

Resources

Brady, Scott. “Road to Recovery.” Overland Journal Summer 2009: 41-51. Burke, Bill, host. Getting UNStuck. Dir. Gregory Hren. DVD. Greg Hren Photography, 2003. Elfstrom, Bruce. “Skills: Winching Without the Worry.” Overland Journal Spring 2009: 105-116. Sheppard, Tom. Four-by-Four Driving. Hertfordshire, England: Desert Winds Publishing, 2006. Vehicle Recovery Overview Stuck Assessment and Planning Passive Recovery Dynamic [...]

  • jim flowers says:

    Congratulations,

    This is one of the best written articles we have come across on the basics of vehicle recovery using the right product for the right application.

    We would like to link to this from our site if that is ok with you?

    Bubbarope.com

    June 4, 2010 at 5:15 am

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