Towing & Yanking Vehicles out of a stuck

[konradh]

A common, quick and easy method of extracting a stuck vehicle is to connect another mobile vehicle to it and yank, pull, or tow it free. Because of the enormous forces generated in this type of operation, extreme care should be exercised. NEVER EVER use chain, wire rope, or a winch to yank another vehicle free. The shock loads developed can multiply the force applied many times, so that a stuck truck requiring a 10,000 lb steady pull to free, can cause a shock-load of 50 000 lbs if jerked or yanked suddenly. This is extremely dangerous to man and machine. As such, only properly designed, constructed, and rated recovery straps should ever be used for yanking vehicles free. DO NOT ever use tow ropes, tow straps, emergency tow ropes etc. These are designed only for easy flat road towing of a non-running vehicle (and are dubious for that, in my opinion) - not for the rigors of off-road extraction and recovery.

The proper recovery straps are designed to stretch when yanked, storing potential energy, which they then release as they "rebound" providing tremendous kinetic energy to free the stuck vehicle, in the safest manner possible. It is best and safest to use recovery straps that have no metal fittings, but rather just sewn loop ends (called eye and eye by industry).

Make absolutely certain that the anchor points on the vehicles in question are capable of handling the loads imposed. Do not ever use recovery straps in combination with wire rope or chains or other devices. Do not join 2 recovery straps together by knotting them.

Care and inspection of nylon recovery straps is extremely important for safe operations, and almost EVERYONE neglects and abuses them (me included!). They should be stored free from water, dirt, and other chemicals. Before use they should be inspected carefully.

Recovery straps are a specialized type of Synthetic Web Sling and as such, the following information, taken from the hoisting industry, regarding synthetic web slings, should be adhered to:

The webbing from which the strap is constructed should have the following characteristics:
1. Sufficient certified tensile strength to meet the sling manufacturer's requirements
2. Uniform thickness and width
3. Full woven width, including selvage edges
4. Webbing ends sealed by heat, or other suitable means, to prevent unravelling
5. Stitching shall be the only method used to form eyes.

Synthetic web slings may be coated with suitable material that will impart the following desirable characteristics:
1. Abrasion resistance
2. Sealing to prevent penetration of foreign particles and matter
3. Increased coefficient of friction
4. Protection from sunlight or ultraviolet degradation.

Marking:
Synthetic web slings shall be labelled (a sewn-on leather tag is recommended). The label shall state the following:
1. Manufacturer's name or trademark
2. Manufacturer's code or stock number
3. Rated loads for the types of hitches used
4. Type of synthetic web material

Design Factor. The design factor for synthetic web slings shall be a minimum of 5.

High radiation or chemically active environments can destroy the strength of synthetic web slings. Sling materials can be susceptible to caustics and acids.

Inspection:
Synthetic web slings shall be removed from service if damage such as the following is visible:
1. Acid, phenolic, or caustic attack
2. Melting or charring on any part of the sling
3. Holes, tears, cuts, or snags
4. Broken or worn stitching in load-bearing splices
5. Excessive abrasive wear
6. Knots in any part of the sling
7. Other visible indications that cause doubt as to the strength of the sling, such as loss of color that may indicate the potential for ultraviolet light damage

Operating Practices:
The following operating practices are applicable to the use of synthetic web slings:
1. Slings having suitable characteristics for the type of load, hitch, and environment shall be selected.
2. The weight of load shall be within the rated capacity of the sling. (The rated capacity is less than or equal to the rated load after sling angles and hitch type are considered.)
3. Slings shall not be shortened or lengthened by knotting or other methods not approved by the sling manufacturer.
4. Slings that appear to be damaged shall not be used unless they are inspected and accepted as usable in accordance with the inspection requirements stated above

6. Sharp corners in contact with the sling should be padded to minimize damage to the sling.
7. Portions of the human body should be kept from between the sling and the load, and from between the sling and the crane hook or hoist hook.
8. Slings should not be pulled from under a load when the load is resting on the sling.
9. Slings should be stored in a cool, dry, and dark place to prevent environmental damage.
10. Twisting and kinking the strap shall be avoided.
11. In a basket hitch, the load should be balanced to prevent slippage.
12. Slings should not be dragged on the floor or over an abrasive surface.
13. Nylon and polyester web slings lose strength from extensive exposure to sunlight or ultraviolet light. Possible strength loss may be indicated by loss of color in the pick threads or outer jacket. If the user suspects sunlight or ultraviolet light damage the sling shall be taken out of service pending inspection by a qualified person.
14. Hard or brittle spots in the fabric of synthetic slings may indicate a substantial reduction in strength as a result of damage from chemicals or excessive heat.

[iguana]

Good infor Konradh, thanx

[MegaMoe]

thx for the info konrad, i was lost in how to use the winch.