BASIC STRUT STABILIZATION TECHNIQUES

I. UNDERSTANDING THE TRIANGLE

ANATOMY OF THE STRUT

THE FUNDAMENTALS OF STABILITY

CREATING OPPOSING FORCES

AVOIDING 4-SIDED SHAPES

I. UNDERSTANDING THE TRIANGLE ANATOMY

OF THE

STRUT

ON-BOARDRATCHET STRAP

BASE PLATE

END FITTING/HEAD(Pictured: RQJ Swivel CRG Head)

PIN(Pictured: Patented RQJ Cone Pin)

CHAIN GRAB

CHANNEL

ROUND POINT

CRG HEAD

THE

FUNDAMENTALS

OF STABILITY

In vehicle rescue, it is important to understand what the

basic form of a stable shape is.

To the left, we have a 4-sided shape. You can imagine that

this diagram is a vehicle that is connected to the ground

with two struts, if you’d like. Or you can stick to just the

shapes. The 4 sides are clearly labeled by the numbers, to

minimize any confusion that might occur when we add more

complexity.

This shape has the freedom to shift and rotate, as shown.

This is the nature of all 4-sided shapes, and is the reason

that we cannot rely on them in our stabilization methods

without additional counteracting forces.

UNSTABLE

THIS SHAPE IS FREE TO MOVE...

LIKE THIS.

TENSION

AND

COMPRESSION

STRUTS work in compression only.

When tension is applied, a strut will separate from the vehicle.

STRAPS work in tension only.

Straps will collapse without tension.

It may sound obvious, but it’s important to understand that you

can’t push with a strap and you can’t pull with a strut. A strut head

is not fastened to the vehicle, and will simply disconnect from a

car if “pulled.” A strap will collapse if there is no tension on it.

UNSTABLE

OPPOSING

FORCES

The forces of the strut (shown by the red arrows)

and the strap (green arrows), are pulling in opposite

directions. This will tend to roll the vehicle, as shown

by the blue arrow in the diagram to the right.

VS

STABLE

OPPOSING

STRUTS

For a much more ideal strut set-up, place struts

and straps on both sides of the vehicle.

Now, as we see in the diagram to the left, the

opposing forces will help, not hinder, the stability

of the vehicle.

VS

ALTERNATIVES

TO OPPOSING

STRUTS

If the situation prevents you from placing struts on opposite sides of the vehicle, stability can still be

achieved. A tie line will resist the push of the strut head on the car, as shown by the opposing blue

and red arrows below. An additional stake in the ground will resist the pull of the strap connecting the

vehicle to the strut, as shown by the green and orange arrows below.

STAKE RESISTS STRAP TENSION

TIE LINE PREVENTS THE VEHICLE FROM ROLLING AWAY FROM THE STRUT

If the situation requires you to remove the strap connecting the strut to the vehicle, which would destroy your triangle, you can add a stake to

the base of the strut. Adding a stake will prevent the strut base from sliding away from the vehicle. In this situation, the ground becomes one

side of the triangle, as the ground connects the two stakes together, just as effectively as the strap in the previous scenario.

STAKE BOTH BASE AND VEHICLE TO CREATE THIRD SIDE OF TRIANGLE

TIE LINE PREVENTS THE VEHICLE FROM ROLLING AWAY FROM THE STRUT

DANGEROUS

4-SIDED

SHAPES

Sometimes, identifying triangles in a scenario can be tricker

than you might think. Notice in the diagram to the right, there

are NO triangles. In this scenario, there is nothing prevent-

ing the car from swinging as it “dangles” from the struts, as

shown by the orange arrows.

When you do not use triangles for stabilization, you have to

rely on ground contact and luck to prevent vehicle movement.

On, the opposite side of the page, we see more examples of

this same danger, but with a roof-resting vehicle.

BAD OKAY GOOD

FIG 1: With this set-up, we run into the same four-sided shape situation that occurred on the opposite page with the side-resting vehicle. The

base-to-base strap prevents the bases from sliding out, but there are no triangles formed, and nothing to prevent vehicle movement.

FIG 2: Here, triangles have successfully been created and the scenario is at the moment stable; however, the bases of the struts are relying on just

the triangles to prevent them from sliding out, so stability can still be improved.

FIG 3: In the best scenario for stability with a roof-resting vehicle, here the base-to-base strap ensures that the bases will not slide, and the sway

straps from strut to vehicle prevent vehicle movement.

FIGURE 1 FIGURE 2 FIGURE 3

II. THE ELEMENTS OF THE TRIANGLE

GENERAL GUIDELINES

TIE-LINES

STRUT POSITIONING

BASE RESTRAINTS

II. THE ELEMENTS OF THE TRIANGLE CHALLENGES OF

STABILIZATION IN

3 DIMENSIONS

So far we’ve been analyzing scenarios two-dimensionally,

which simplifies the scenarios. However, it’s important to

consider the additional real-life challenges and techniques

that come with stabilization in all 3 dimensions.

It is important to step back, look at the big picture, look in

all directions, and use stakes, pickets, and tie lines whenever

necessary to achieve stability.

You also must understand some of the basic principles behind

strut placement, strap placement, and counteracting forces.

LIFTING VEHICLES

WITH RES-Q-JACK®

STRUTS

While struts that simply stabilize a vehicle are common, Res-Q-Jack®

struts are designed to be active rescue tools, and continue to lift the

stabilized vehicle if the situation requires it.

For that reason, Res-Q-Jack training includes techniques that allow for

both rapid stabilization as well as a quick transition into lifting.

To that end, these techniques need to focus on secure engagement

and arranging base restraints in such a way that they will not interfere

with lifting.

The ability to lift with struts can be the life-saving difference.

UNSTABLE VSTIE-LINES

Tie-lines should act in an EQUAL

AND OPPOSITE way to avoid

twisting or shifting of the vehicle.

In the unstable example shown

directly to the right, we show the

result of misaligned tie-lines. If you

were to tighten all of these straps,

you would start to rotate the vehicle,

which is not the desirable result.

STABLEVSIn this stable example to the left, the tie-

lines are aligned perfectly, which will result

in zero rotation of the vehicle.

In real life situations, this is very difficult to

achieve, but practicing and keeping these

opposite forces in mind will help you to

come close, and that will be good enough.

Sometimes we might selectively tighten our

straps to make slight adjustments to the

orientation of the vehicle.

UNSTABLE!

TIE-LINES IN THREE DIMENSIONS

The scenario shown below is the same scenario as in the previous two pages, but this time viewed from the side.

Now we see other concerns in terms of stability. If we aren’t careful with how we place the straps, we can cause unwanted movement. In

this case, tightening the rear tie-line would tip the car toward the trunk, as shown by the blue arrow below.

STRUT POSITIONING

Keeping in mind basic rules of thumb when

setting up your struts will ensure that the set-

up is stable, and instantly ready to go when a

lifting operation is needed.

The strut should be placed as shown in the

diagram to the right, with about an arm’s

length between the base of the strut and the

wheel of the vehicle. The strut should lean at

a 40-70 degree angle and there should be a

minimum of 4” between the strut and the door

skin.

40° - 70° ANGLE

ARM’S LENGTH

BASE RESTRAINTS

Base restraints should be positioned at the

largest possible angle under 90°.

Creating a large angle here restrains the base

most effectively. Because the base of the strut

will tend to move away from the car along the

ground, a strap close to the ground will best

counteract that force.

Also, a larger angle will work best when we

transition from simple stabilization to a lifting

operation. ‹ 90° ANGLE

The diagrams below show the difference between a stable and unstable angle when positioning a base restraint with a special ground contact

situation. This diagram shows a large hill next to the vehicle, but the same concepts will apply if you put your strut base on the wrong side of

a hump, bump, or hole in the ground.

If the base restraint is positioned in a greater than 90° angle, as shown to the left, the strut will have a tendency to slide down the slope,

toward the vehicle. This will result in the strut coming loose and falling down.

‹ 90°

› 90°

UNSTABLE STABLE

When you are using a single base restraint, position it in line with the strut.

An example of incorrect positioning is shown in the diagrams of the side-resting vehicle below. If we place a base restraint as shown below,

it will tend to pull the base plate to the sides (to the left on the diagram to the left, and to the right on the diagram to the right). This move-

ment in turn could cause the strut to become loose, or could cause the car to shift in unwanted ways.

UNSTABLE UNSTABLE

STABLETo the right, we see the correct positioning

of the base restraint. As it is in line with

strut, we can barely see it, looking head on.

When the strap is attached in line with the

strut, as shown, the tension in the strap will

tighten the strut against the vehicle, creating

a secure strut engagement.

UNSTABLE

If we attach our base restraints too high or too close to the end fitting, as shown below, the strap will not restrain our base. The angle of the

strap will not keep the base from sliding away, and could even act like a hinge.

A COMMON BASE RESTRAINT MISTAKE

TRULY VERTICAL

STRUTS DON’T NEED

A BASE RESTRAINT

If a strut is standing perpendicular to the ground,

as shown to the left, as if sitting vertically on level

ground, the ground directly counteracts the force of

the strut, so you don’t need to use a base restraint.

This is illustrated by the red and green arrows.

If a base restraint IS used, you must place a second

counteracting strap in the opposite direction, to

prevent the base from sliding. This is illustrated by

the purple arrows, to the right.