Manitowoc National Crane NBT30H-2 User Manual

SET-UP NBT30H-2 OPERATOR MANUAL
4-8
Published 03-18-2019 Control # 582-04
ANTI-TWO BLOCK WEIGHT INSTALLATION
To prevent the hoist cable from slipping out of the anti-two
block weight, rig the weight as shown in Figure 4-4.
The A2B bracket is for single part line use only. Remove the
A2B bracket shown in Figure 4-4 from the hoist cable when
changing from a single part line to a multiple part line to allow
the hoist cable and wedge socket to reeve through the
sheaves on the boom nose and the hookblock. Re-install the
clamp and nuts to the cable before performing a lift.
MULTI-PART LINE REEVING
Multi-part line reeving enables greater loads to be lifted than
can be lifted with single part line. However, loads are limited
by the stability and structural integrity of the crane. The load
must be within the limits contained in the load chart.
Using Multiple Part Lines
The hoist data chart provides information for pull limitations
on the hoist with various multi-part reevings. These ratings
are based on providing the proper operating safety factor on
the cable supplied with the machine. Therefore, any
replacement rope must meet the cable specification in this
manual.
The A2B bracket is for single part line use only. Remove the
A2B bracket shown in Figure 4-4 from the hoist cable when
changing from a single part line to a multiple part line to allow
the hoist cable and wedge socket to reeve through the
sheaves on the boom nose and the hookblock. Re-install the
clamp and nuts to the cable before performing a lift.
Lifting a 30 Ton (60,000 lb) Load
The NBT30H-2-2 is rated to lift 27,216 kg (60,000 lbs) at a
1.83 m (6 ft) radius with all booms retracted with a seven part
block. To make this lift the crane must be equipped with
optional 6 x 25 IWRC wire rope with a rated breaking
strength of 15,241 kg (33,600 lb). This rope is required to
have the appropriate 3.5:1 safety factor.
It is also necessary to increase the hoist system hydraulic
pressure relief valve from (22,753 kPa (+690/-0) to 23,787
kPa (+690/-0) [3,300 psi (+100/-0) to 3,450 psi (+100/-0)].
See the Service Manual. This is required to increase the
hoist pull to 3,901 kg (8,600 lbs) to achieve the 60,000 lbs lift
with seven part rigging.
FIGURE 4-4
The anti-two-block chain
must be installed
between the slot in the
weight and the hoist
cable.
Anti-two Block
Weight
Hoist
Cable
Slot
Chain Length 40 cm
(16 inches) Do not
shorten the chain.
Upper Link
Lower Link
The A2B bracket must be
removed from the hoist
cable when reeving for
multi-part line.
8835
CAUTION
Equipment Damage Hazard!
All components on the crane are rated for intermittent
operation under these conditions. After this lift is
completed the hoist operating pressure must be reduced
back to 22.7 kPa (3,300 psi).
Continuous operation of the hoist hydraulic system at
nominal pressures greater than 22.7 kPa (3,300 psi) will
shorten the life of hydraulic components and void their
warranty.

Manitowoc National Crane NBT30H-2 Specifications

General

Brand	Manitowoc
Model	National Crane NBT30H-2
Category	Construction Equipment
Language	English