Manitowoc National Crane NBT50 Series, Руководство оператора

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2-20
Published 03-23-2018 Control # 243-14
SAFETY PRECAUTIONS NBT50 OPERATOR MANUAL
Refer to the above Lifting Limits at wind speed V(z)
> 30 mph and ≤ 45 mph . Comparing the load and wind
resistant area to the allowable:
• Is the load to be lifted less than allowable load?
12,000 lb
≤ 20,160 lb YES
• Is Awr
(load)
less than Awr
(allow)
,?
162 ft
2
≤ 119 ft
2
NO
Conclusion : This load is NOT permissible to lift in wind
speed up to 45 mph, but permitted to lift at a reduced wind
speed calculated as follows:
Ratio = 1.37
From Table Table 2-7, the maximum permissible wind speed
at ratio of 1.37 (rounded to next higher table value of 1.4) is
38.0 mph.
Conclusion : This load is permissible to lift in wind speed up
to 38.0 mph only.
Lifting Operations
Before lifting, position the crane on a firm surface, properly
extend and set the outriggers, and level the crane.
Depending on the nature of the supporting surface,
adequate cribbing may be required to obtain a larger bearing
surface.
The crane is equipped with a bubble level that should be
used to determine whether the crane is level. The load line
can also be used to estimate the levelness of the crane by
checking to be sure it is in-line with the center of the boom at
all points on the swing circle.
If the boom extension, or auxiliary boom nose is to be used,
ensure the electrical cable and the weight for the Anti-Two-
Block Switch are properly installed and the Rated Capacity
Limiter (RCL) is programmed for the crane configuration.
Refer to the RCL operator manual supplied with the crane.
Verify the crane’s capacity by checking the Load Chart
against the weight of the load. Then, lift the load slightly at
first to ensure stability before proceeding with the lift.
Be sure the load is properly rigged and attached. Always
determine the weight of the load before you attempt to lift it
and remember that all rigging (slings, etc.) and lifting devices
(hook block, boom extension, etc.) must be considered part
of the load.
Measure the load radius before making a lift and stay within
approved lifting areas based on the range diagrams and
working area diagrams on the crane’s
Load Chart .
Always keep the load as near to the crane and as close to
the ground as possible.
Do not overload the crane by exceeding the capacities
shown on the appropriate Load Chart . Death or serious
injury could result from the crane tipping over or failing
structurally from overload.
The crane can tip over or fail structurally if:
• The load and crane’s configuration is not within the
capacity as shown on the applicable
Load Chart and
notes.
• The ground is soft and/or the surface conditions are
poor.
• Outriggers are not properly extended and set. On
models equipped with outriggers that can be pinned at
the mid-extend position, the outriggers must also be
pinned when operating from the mid-extend position.
• Cribbing under the outrigger pads is inadequate.
• The crane is improperly operated.
Do not rely on the crane’s tipping to determine your lifting
capacity.
Be sure the hoist line is vertical before lifting. Do not subject
the crane to side loading. A side load can tip the crane or
cause it to fail structurally.
Load Chart capacities are based on freely suspended loads.
Do not pull posts, pilings, or submerged articles. Be sure the
load is not frozen or otherwise attached to the ground before
lifting.
If you should encounter a tipping condition, immediately
lower the load with the hoist line and retract or elevate the
boom to decrease the load radius. Never lower or extend the
boom; this will aggravate the condition.
Use tag lines whenever possible to help control the
movement of the load.
When lifting loads, the crane will lean toward the boom and
the load will swing out, increasing the load radius. Ensure the
crane’s capacity is not exceeded when this occurs.
Do not strike any obstruction with the boom. If the boom
should accidentally contact an object, stop immediately.
Inspect the boom. Remove the crane from service if the
boom is damaged.
Never push or pull with the crane boom.
Avoid sudden starts and stops when moving the load. The
inertia and an increased load radius could tip the crane over
or cause it to fail structurally.
Using only one hoist at a time when lifting loads is
recommended. See “Tilt-Up Panel Lifting” on page 2-21 for
additional lifting instructions.
Always use enough parts-of-line to accommodate the load to
be lifted. Lifting with too few parts-of-line can result in failure
of the hoist rope.