Instruction Manual

MS 461 R
English
16
DANGER
Roof-Venting
Fire and rescue departments in North
America frequently engage in the
practice of "roof-venting" structures
involved in fires to help evacuate
penned-up heat and smoke by sawing
vent openings into the top layer of a
building.
Roof-venting usually means physically
placing one or more fire fighters on or
near the roof of a structure, that may still
be burning and forcing openings either
manually or with a chain saw. There are
several ways to make such an opening,
but many, if not most, run counter to
standard safe and sound operating
principles for handheld power
equipment, primarily due to insecure
footing.
REACTIVE FORCES INCLUDING
KICKBACK
WARNING
Reactive forces may occur any time the
chain is rotating. Reactive forces can
cause serious personal injury.
The powerful force used to cut wood can
be reversed and work against the
operator. If the rotating saw chain is
suddenly and significantly slowed or
stopped by contact with any solid object
such as a log or branch or is pinched, the
reactive forces may occur instantly.
These reactive forces may result in loss
of control, which, in turn, may cause
serious or fatal injury. An understanding
of the causes of these reactive forces
may help you avoid the element of
surprise and loss of control. Surprise
contributes to accidents.
The most common reactive forces are:
– kickback,
– pushback,
– pull-in.
WARNING
Kickback:
When this occurs, the energy driving the
saw chain can create a force that moves
the chain saw in a direction opposite to
the saw chain movement at the point
where the saw chain is slowed or
stopped. This may fling the bar up and
back in a lightning fast reaction mainly in
the plane of the bar and can cause
severe or fatal injury to the operator.
Kickback may occur, for example, when
the saw chain near the upper quadrant
of the bar nose contacts the wood or is
pinched during limbing or when it is
incorrectly used to begin a plunge or
boring cut.
Do not rely on the chain
saw ’s insulation against
electric shock. To reduce
the risk of electrocution,
never operate this chain
saw in the vicinity of any
wires or cables (power,
etc.) which may be carry-
ing electric current. To
reduce risk of electrocu-
tion, take extra
precautions when cutting
near power lines. Have
the power switched off
before starting cutting
work in the immediate
vicinity of power lines.
001BA257 KN
Kickback may occur
when the moving saw
chain near the upper
quadrant of the bar nose
contacts a solid object or
is pinched.
001BA035 KN