Download EMA 4WD Manual PDF

TitleEMA 4WD Manual
File Size1.6 MB
Total Pages76
Table of Contents
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Amendment List
1 Introduction
2 Attitude & Safety - General
3 Vehicle Servicing, Maintenance & Equipment
	Equipment Lists
4 Loads & Lashing
5 4WD Techniques
	Annex A - Stall Procedure
6 Towing & Trailers
7 Recovery
Document Text Contents
Page 2


Skills for Emergency Services Personnel

Manual 8



Page 38

show safe usage and Australian Standards compliance. This information
should be referred to before any slinging is undertaken.

4.25 The most common types of slings are as follows:

a. SWR single leg slings with swaged eyes at each end or with a hook at
one end and a ring or eye at the other to AS 1666 of 1976.

b. Superflex high-tensile plaited cable slings to AS 1666 of 1976.

c. Synthetic webbing slings of single leg or round sling design to
AS~`1353 Parts 1 and 2 of 1990.

d. Polyester round slings with fibre core and braided sheath to AS~`1353.

e. Polyester laid fibre rope slings to AS 1380 of 1972.

f. Chain slings of various grades to AS 3775 of 1990.


Rescue slings must be inspected regularly, and after each operational use.
Where slings are found to be defective they must be immediately withdrawn
from service and the record of inspections must be properly maintained.


The recommended procedures for performing an inspection are as follows:

a. Clean each sling prior to its inspection. Dirt will hide defects that may be
obvious on clean slings.

b. Each leg of the sling assembly should be measured to make sure that
the length corresponds with the length stamped on the sling ID tag. An
increase in length of more than three per cent (3%) indicates possible
overload damage to the chain sling or other low elongation sling.

c. Check each link of a chain sling for excessive wear, twisted or bent
links, cuts, nicks, or gouges, and stretched links. If wear exceeds 15 per
cent (15%) of the original diameter of the link, the chain should be
removed from service. A five per cent (5%) stretch on any link should
be considered the maximum allowable.

d. Inspect master links, couplers, load pins, shackles, swaging and
thimbled eye for wear or damage. If wear on any of these components
exceeds 15~`per~`cent (15%) of the original materials, remove the sling
from service.

e. Check all stitching or splicing for signs of overload or damage.

f. If hooks have been stretched out more than 15 per cent (15%) of of
their their original opening width, twisted more than 10 degrees from
plane, they should be removed from service.

Page 39

g. Attach a ‘Danger-Do Not Use' tag to any sling taken out of service, and
repair or destroy the sling as soon as possible.


The method of slinging any given object must vary according to
circumstances, but the following general rules and precautions should be
observed to ensure safe working:

a. The size and therefore Safe Working Load of the sling will be governed
by the weight of the load.

b. Timber packing must be inserted between the sling and the edges of
the load to prevent the sling coming into contact with sharp edges.

c. Hooks must be moused, preferably with factory-fitted automatic

d. Wire rope or chain slings must not be bent around too sharp an angle.
To prevent this, packing may be necessary.

e. Avoid carelessness in hoisting. Particularly avoid shock-lifting or
snatching loads.

f. Slings should not be dragged along the floor or ground and should
never be pulled from under a load which, when lowered, rests on the
sling. Timber blocks should be placed to receive a lowered load to allow
for easy removal of the slings.

g. A common misconception when slinging, is that if the number of legs in
the sling is increased, the Safe Working Load is the safe load on one
leg multiplied by the number of legs in use. This is only true when all
legs are in the vertical position.

h. When rigging with two leg slings, or rigging two slings from anchor
points to support a load, the angle formed by the legs must not be more
than 120 degrees, and should preferably be less than 90~`degrees. The
greater the angle, the higher the loading on each leg. (See Figure 4:3).

i. Slings must never be shortened by knotting, as this will cause
excessive stresses, and may result in damage or failure.

j. Avoid ‘tip-loading' of hooks. Open hooks are designed to support the
load in the bowl of the hook. Be sure the hook engages freely at the
lifting or pulling point so that the load's weight or force acts along the
designed line of force in the bowl of the hook. Forcing the hook tip into
the pulling point, where the load does not rest in the bowl, may damage
and deform the hook, as well as cause complete failure.

k. Always remove twists from slings before preparing to pull or lift.

l. A rescue sling will break for one of two reasons: Either the chain was
too light for the force applied; or there was a sudden application of a
load which, except for the sudden shock, the chain would normally be

Page 75

(3) the jack is high enough to just clear the obstacle—do not raise the
vehicle more than necessary; and

(4) you have packed under the wheel with suitable material.

NOTE: Jack up the lower side rather than the higher side (if roll over
is likely, secure the vehicle using suitable rope and/or a
winch before jacking).

c. When clearance has been gained, remove the jack and wheel chocks,
then ‘inch' the vehicle over the obstacle.


7.29 A snatch-em-strap is a type of webbing tow rope that can be stretched like a
rubber band. The snatch-em-strap allows the towing vehicle to build up
momentum, and use the momentum combined with the vehicles normal
power to pull a vehicle out of a bog.


Snatch-em-straps can result in considerable dynamic loads. This has been
known to cause tow bars to be sheared and flung into windscreens and ‘D'
shackles to be torn from mounting points and propelled through vehicle body
panels. Only trained personnel should use this device.

Page 76


The Glovebox guide to 4 Wheel Driving by Bernard R. Kestel, Forestry Commission of NSW

Four-Wheel-Drive Vehicles, Drivers Handbook Telecom Australia,

South Australian Police Department, Driver Training Notes,

Australian Army School of Transport Driver Training Notes

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