NATIONAL CRANE Published 03-23-2018 Control # 243-14 4-1
NBT50 OPERATOR MANUAL SET-UP
SECTION 4
SET-UP
SECTION CONTENTS
Outrigger Setup . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-1
Proper Leveling of the Crane . . . . . . . . . . . . . . . . 4-1
Bubble Level Adjustment . . . . . . . . . . . . . . . . . . . 4-1
Site Selection . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-2
Setting the Outriggers . . . . . . . . . . . . . . . . . . . . . . 4-2
Jib Safety Information . . . . . . . . . . . . . . . . . . . . . . 4-3
Erecting And Stowing The Jib. . . . . . . . . . . . . . . . 4-3
General Warnings . . . . . . . . . . . . . . . . . . . . . . . . . 4-3
Jib Operation. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-4
Deployment Procedure . . . . . . . . . . . . . . . . . . . . . 4-4
Stowing Procedure . . . . . . . . . . . . . . . . . . . . . . . . 4-7
Jib Removal. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-8
To install, proceed in reverse order of removal. . . 4-9
Jib Maintenance. . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-9
Setting the Offset . . . . . . . . . . . . . . . . . . . . . . . . . . 4-9
Setting the Offset Mast . . . . . . . . . . . . . . . . . . . . . 4-9
Anti-Two-Block Weight Installation . . . . . . . . . . . 4-12
Multi-part Line Reeving. . . . . . . . . . . . . . . . . . . . . 4-12
Using Multiple Part Lines . . . . . . . . . . . . . . . . . . . 4-12
Lifting the Rated Load . . . . . . . . . . . . . . . . . . . . . 4-12
Installing Cable on the Hoist . . . . . . . . . . . . . . . . 4-13
Wedge Sockets . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-14
Terminator Wedge Installation. . . . . . . . . . . . . . . 4-14
Wedge Socket Installation . . . . . . . . . . . . . . . . . . 4-15
Removable Counterweight . . . . . . . . . . . . . . . . . . 4-17
Mounting the Counterweight . . . . . . . . . . . . . . . . 4-17
Stowing the Counterweight . . . . . . . . . . . . . . . . . 4-19
This section contains information on how to perform the
following tasks:
• Set the outriggers
• Erect the jib
• Stow the jib
• Remove the jib
• Use multipart reeving
• Install the hoist cable
• Install the anti-two-block weight
• Install a wedge socket
• Mount/stow the removable counterweight
OUTRIGGER SETUP
Proper Leveling of the Crane
ASME B30.5 specifies that if a crane is not level within 1% of
grade, the allowable capacities must be reduced. It is
essential that the crane is level to within 1% of grade. The
bubble level that is provided on the crane is calibrated to be
accurate within 1% of grade.
To properly level the crane, the boom must be positioned
over the front of the crane, fully lowered to horizontal and
fully retracted (for cranes fitted with a boom rest, the boom
shall be stowed onto the rest). Raise and level the crane
using the outriggers; refer to Setting the Outriggers, page 4-
2.
A working crane may settle during lifting operations.
Frequently check the crane for level. When rechecking the
crane for level, the boom must be positioned over the front of
the crane, fully lowered to horizontal and fully retracted (for
cranes fitted with a boom rest, the boom shall be stowed
onto the rest). If necessary, relevel the crane using the
procedures under Setting the Outriggers, page 4-2.
Bubble Level Adjustment
The bubble level adjustment should be checked periodically;
if it is suspected that the bubble level indicator is out of
adjustment, verify and adjust the bubble level as follows:
1. Position the crane on a firm, level surface.
2. Extend and set the outriggers. Level the crane, as
indicated by the bubble level indicator, using the
outriggers.
3. Place a miracle pointer level, carpenter level, or similar
type device on a machined surface such as the turntable
bearing or bearing mounting surfaces.
DANGER
Do not operate outriggers unless they are visible to either
the operator or a designated signal person to avoid
crushing injury.
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