Komatsu PC500LC-10R Shop Manual page 20

SAFETY NOTICE FOR OPERATION
REMARK
When slinging a load with 2 or more ropes, the force sub-
jected to each rope increases with the hanging angle. The
figure below shows the variation of allowable load in kN
{kg} when slinging is made with 2 ropes, each of which is
allowed to sling up to 9.8 kN {1000 kg} vertically, at vari-
ous hanging angles. When the 2 ropes sling a load verti-
cally, they can sling up to 2000 kg of total weight. This
weight is reduced to 1000 kg when the 2 ropes make a
hanging angle of 120 °. If the 2 ropes sling a 2000 kg load
at a hanging angle of 150 °, each rope is subjected to a
force as large as 39.2 kN {4000 kg} .
• When installing wire ropes to an angular load, apply pads to protect the wire ropes. If the load is slippery,
apply proper material to prevent the wire rope from slipping.
• Use the specified eye bolts and fix wire ropes, chains, etc. to them with shackles, etc.
• Apply wire ropes to the middle part of the hook.
k
Do not use hooks if it does not have a latch sys-
tem.
k
Slinging near the tip of the hook may cause the
rope to slip off the hook during hoisting.
REMARK
The strength of the hook is maximum at its central part.
• Never use a wire rope which has breaks in strands (A), re-
duced diameter (B), or kinks (C). There is a danger that
the rope may break during the towing operation.
Precautions for slinging up
• Wind in the crane slowly until wire ropes are stretched.
When settling the wire ropes with the hand, do not grasp
them but press them from above. If you grasp them, your
fingers may be caught.
• After the wire ropes are stretched, stop the crane and
check the condition of the slung load, wire ropes, and
pads.
• If the load is unstable or the wire rope or chains are twisted, lower the load and lift it up again.
• Do not lift up the load at an angle.
Precautions for slinging down
• When slinging down a load, stop it temporarily at 30 cm above the floor, and then lower it slowly.
• Check that the load is stable, and then remove the sling.
• Remove kinks and dirt from the wire ropes and chains used for the sling work, and put them in the specified
place.
Precautions for using mobile crane
REMARK
Read Operation and Maintenance Manual of the crane carefully in advance and operate the crane safely.
Precautions for using overhead traveling crane
k
When raising a heavy component (heavier than 25 kg), use a hoist or crane.
00-18
00 INDEX AND FOREWORD
PC500LC-10R