Maeda CC1908S-1, Operation Manual

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5.4 CRANE OPERATION M A E D A Crawler Crane
5-26 5/2020 CC1908S-1
• Extending the boom increases the working
radius and reduces the rated total load that
can be hoisted. When extending or retracting
the boom, pay extra attention so that the
weight of the load when the boom is most
extended does not cause overloading.
PRECAUTIONS WHEN SLEWING
• Check the safety around the machine, and
sound the horn before slewing.
• Operate the slewing lever as slowly as
possible. Start smoothly, slew at low speed,
and stop gently.
Especially avoid sudden lever operations when
a load is hoisted, which may cause the load to
sway and make the machine unstable,
damaging the crane or causing the machine to
topple.
• Never attempt to draw in a load or stand it
upright by slewing.
• Be careful to prevent the wire rope and/or
hoisted load from coming into contact with
obstructions such as trees or girders when
hoisting a load or slewing.
If the wire rope becomes entangled by an
obstruction, do not forcibly wind up the hoisted
load, but untangle the caught part before
winding up.
JOINT HOISTING IS PROHIBITED UNDER
NORMAL CIRCUMSTANCES.
Joint hoisting, where two or more cranes are
used to hoist a single load, is prohibited under
normal circumstances.
Joint hoisting is a highly dangerous operation
that may cause the machine to topple due to an
offset centre of gravity. It can also cause the
hoisted load to fall or cause damage to the boom.
If joint hoisting is required for unavoidable
reasons, discuss and establish a work scheme
under the responsibility of the user, make sure
the workers fully understand the work methods
and procedures, and only proceed under the
direct leadership of the work supervisor.
Also, observe the following precautions:
• Use identical crane models.
• Select models that can handle sufficiently
larger loads than the load to be hoisted.
• Make sure only one person gives signals.
• Limit the crane operations to single operations,
and do not slew.
• Appoint one responsible sling operator who is
the most experienced.
PRECAUTIONS AT WORKSITES WHEN
LIFTING BELOW GROUND LEVEL
• When lowering a wire rope for work
underground, leave at least three turns of wire
rope on the winch drum.
• Make sure signals are given.
• Take extra care when operating the crane.
PRECAUTIONS DURING PICK & CARRY
Pick & Carry is extremely unstable and
dangerous and is prohibited under normal
circumstances.
The following points must be adhered to if Pick &
Carry is unavoidable. There is a risk of serious
personal injury if these precautions are not
adhered to.
• Strictly adhere to the precautions described in
the instruction manual.
Refer to "5.5.1 PRECAUTIONS DURING PICK
& CARRY" on P. 5-44
.
• Strictly adhere to the precautions on the
operation details for the working posture
prescribed in the instruction manual.
Refer to "5.5.2 PICK & CARRY POSTURE" on
P. 5-45.