CMC Rescue, Inc.
|
A Z VORTEX User’s Manual
12
A-Frame
An A-frame set up requires the legs to
be secured by anchoring the feet to the
surface and attaching guy lines to keep the
A-frame in position as shown in
Figure 11
.
The guy lines should be under tension to
eliminate movement. If the feet cannot be
individually secured, the legs must be tied
together. An A-frame requires guy lines
connected to anchors both in the front (near
or over the edge) and in the back.
Additional guy lines may be needed to
prevent the A-frame from moving sideways
if the load should shift.
To maximize the force supported by the
legs and minimize the forces on the guy
lines, lean the A-frame slightly towards the
edge. The legs and the axle of the pulley
should line up when the legs bisect the
angle of the Working Line through the
pulley, as shown in
Figure 12
. The
resultant force should also be centered
between the legs. This balances the forces
for stability and allows the legs to take most
of the load.
Figure 11
Figure 12
