Manitowoc National Crane NBT40 Series User Manual

National Crane Published 4-23-2018 Control # 239-11 4-9
4
NBT40 SERIES OPERATOR MANUAL SET-UP
5. Insert the wedge into the loop and pull the live-end of the
rope until the wedge and rope are snug inside the
socket. It is recommended that the wedge be seated
inside the socket to properly secure the wire rope by
using the crane’s hoist to first apply a light load to the
live-end.
6. After final pin connections are made, increase the loads
gradually until the wedge is properly seated.
7. The wire rope and wedge must be properly secured
inside the socket before placing the crane into lifting
service. It is the wedge that secures the wire rope inside
the socket. The dead-end treatment is used to restrain
the wedge from becoming dislodged from the socket
should the rope suddenly become unloaded due to the
headache ball or hook block striking the ground, etc;
refer to “Dead-end Rigging” on page 2-9.
Dead-end Rigging
Sketches A through F (Figure 4-7) illustrate various ANSI
approved methods for treating the dead-ends of wire ropes
which exit a wedge socket assembly. While use of the loop-
back method is acceptable, care must be exercised to avoid
the loop becoming entangled with tree branches and other
components during crane transport and with the anti-two
block system and other components during use of the crane.
Of the methods shown below, Manitowoc prefers that
method A or F be used, i.e., clipping a short piece of wire
rope to the dead-end or using a commercially available
specialty wedge. Typically, it is recommended that the tail
length of the dead-end should be a minimum of 6 rope
diameters but not less that 6 in (15.2 cm) for standard 6 to 8
strand ropes and 20 rope diameters but not less than 6 in
(15.2 cm) for rotation resistant wire ropes.
When using method A, place a wire rope clip around the
dead end by clamping a short extra piece of rope to the rope
dead end. DO NOT CLAMP THE LIVE END. The U-bolt
should bear against the dead end. The saddle of the clip
should bear against the short extra piece. Torque the U-bolts
according to the table titled Wire Rope Clip Torque Values
(Table 4-1).
Other sources for information with which crane users should
be familiar and follow is provided by the American Society of
Mechanical Engineers, American National Standard, ASME
B30.5, latest revised. ASME (formerly ANSI) B30.5 applies
to cableways, cranes, derricks, hoists, hooks, jacks, and
slings. It states, in section 5-1.7.3, “(c) Swagged,
compressed, or wedge socket fittings shall be applied as
recommended by the rope, crane or fitting manufacture.”
Wire ropes are addressed in ASME B30.5, section 5-1.7.2,
ROPES, it states, in pertinent part, “(a) The ropes shall be of
a construction recommended by the rope or crane
manufacturer, or person qualified for that service.” Additional
information is published by the Wire Rope Technical Board in
the Wire Rope Users Manual, latest revised edition.
Table 4-1
Wire Rope Clip Torque Values
Clip Sizes Torque
Inches mm lb-ft Nm
1/8 3.18 4.5 6
3/16 4.76 7.5 10
1/4 6.35 15 20
5/16 7.94 30 40
3/8 13.28 45 60
7/16 11.11 65 90
1/2 12.70 65 90
9/16 14.29 95 130
5/8 15.88 95 130
3/4 19.05 130 175
7/8 22.23 225 300
1 25.40 225 300
1-1/8 28.58 225 300
1-1/4 31.75 360 490
1-3/8 38.68 360 490
1-1/2 38.10 360 490

Manitowoc National Crane NBT40 Series Specifications

General

Brand	Manitowoc
Model	National Crane NBT40 Series
Category	Construction Equipment
Language	English