Maeda MC815C, Operation Manual, Page: 54 / 426

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PAY ATTENTION TO WEATHER INFORMATION
• A risk of lightning exists in case of a thunderstorm, so abort operating the crane, immediately
lower the load and retract the boom.
• Wind can cause the hoisted load to move back and forth, which could cause the machine to
become unstable. If the hoisted load is affected, immediately lower the load and retract the
boom.
• If the maximum instantaneous wind speed is 10 m/s or greater, abort operating the crane,
immediately lower the load and retract the boom.
• Even when the maximum instantaneous wind speed is below 10 m/s, the bigger the hoist
load, the higher the hoist load position, or the longer the boom can increase the effect from
the wind. Be very careful during the work.
• When a load such as a steel plate that has a large area exposed to wind is being hoisted, the
wind arriving from front/rear/side of the boom may cause the Machine to trip or damage the
boom. Be very careful during the work.
• When an earthquake occurs, abort the operation and wait until it is over.
The following table indicates approximate relation between the wind speed and wind effect.
The wind speed mentioned in the weathercast is mean wind velocity (m/s) during 10 minutes
at 10 m above the ground.
Force Wind Speed (m/s) Effect On Land
0 Less than 0.3 Smoke rises vertically.
1 0.3 - below 1.6 Wind motion visible in smoke.
2 1.6 - below 3.4 Wind felt on exposed skin.
3 3.4 - below 5.5 Leaves and small twigs move in constant motion.
4 5.5 - below 8.0
Dust and loose paper blow up. Small branches begin to
move.
5 8.0 - below 10.8
Bushes with leaves start to sway. Waves form on the face
of pond/swamp.
6 10.8 - below 13.9
Large branches begin to move. Whistling heard in
electrical wires. Use of umbrella becomes difficult.
7 13.9 - below 17.2
Whole trees start to shake. Effort needed to walk against
the wind.
8 17.2 - below 20.8 Twigs broke from trees. Progress impeded.
9 20.8 - below 24.5 Light structure damage. Slates blown off.
10 24.5 - below 28.5 Trees uprooted. Considerable structural damage.
11 28.5 - below 32.7 Widespread structural damage.