National Crane Published 4-23-2018 Control # 239-11 4-3
NBT40 SERIES OPERATOR MANUAL SET-UP
d. Open the jack release valve and retract the jack (F,
Figure 4-1.
14. Using hoist function, un-spool enough loadline to reeve
loadline over jib sheave case. Keep slight tension on
loadline to avoid bird caging of loadline on hoist drum.
15. Route loadline over jib sheave and install keeper. Install
line block to end of loadline.
16. Remove anti-two-block switch and weight/chain
assembly and install on jib tip, see Figure 4-2. Be certain
to use keeper provided with switch.
17. Disconnect anti-two- block cord going to boom anti-two-
block switch and attach to quick coupler on jib anti-two-
block wire on rear of jib between the upper and lower jib
ears.
18. Install jib swing pin (B, Figure 4-1) and spring clip into jib
ears.
19. For manually extendable jibs, pull extension retaining
pin (E, Figure 4-1), and extend second section out by
pulling on sheave case. The second section jib, as it
extends, will hit a mechanical stop that allows for
extension pin (E) installation. Install pin (E) and spring
clip.
20. Make ATB cord connections as required.
Stowing Procedure
Depending on the length of the jib extension being used; the
crane can be equipped with either a two section or one
section jib. Certain stowing instructions may only applied to
one or the other and will be noted so.
1. Using lift function, lower boom so that jib deployment
pins (C1, Figure 4-1) and (C2, Figure 4-1) are easily
accessible from the ground.
NOTE: When lowering the boom below horizontal, two
persons may be required. With the telescope
control in neutral, the boom may creep out when
below horizontal.
2. Two section jib - For manually extendable jibs, pull
extension retaining pin (E, Figure 4-1) and fully retract
extendable 2
nd
section jib into the 1
st
section. Retraction
of 2
nd
section may be facilitated by attaching loadline
wedge socket to jib nose. Slowly activate the hoist up
function until the 2
nd
section is fully retracted.
3. Two section jib - Reinstall extension retaining pin (E,
Figure 4-1 through the 1
st
and 2
nd
section jib assembly
and install spring clip.
4. Remove loadline from jib sheave case. Place loadline in
area to avoid possible damage from stow procedure.
5. Disconnect anti-two-block wire connector at rear of the
jib extension. Re-connect anti-two-block switch
connector on boom tip. Move weight/chain assembly to
boom tip see Figure 4-2.
6. Attach tag line to sheave case end of jib.
7. Remove spring clips from pins (C2, Figure 4-1) on both
upper and lower jib ears.
8. Remove jib swing pin (B, Figure 4-1) from the boom
nose.
9. Remove pins (C2, Figure 4-1) from upper and lower jib
ears. Do not remove (C1) pins at this time. C1 pins will
be used as a pivot point to swing jib into stow position. A
slight hammer strike may be necessary to remove pins.
Always use proper eye protection during this step.
10. Raise the boom to the horizontal position.
11. Extend boom approximately 1 foot (.3m).
12. Using tag line attached to jib sheave case, slowly swing
jib into stow position (parallel with 1
st
section boom),
Pins (C1, Figure 4-1) are the jib pivot points during this
operation.
:
13. Install jib swing pin (B, Figure 4-1) with spring clip
through jib ear and boom sheave case holes. This pin
will keep the jib assembly in line (parallel) with the I
st
section boom.
NOTE: Jib swing pin (B, Figure 4-1) does not retain the jib
in its stowed position on the I
st
section boom.
DANGER
Visually check all pin positions and make sure the jib is
fully retracted into side stow brackets, jib stow attachment
is secure, and all pins and spring clips are in their proper
locations. Failure to proper secure the jib during stowing
and erecting may allow the jib to fall. Serious personal
injury or death could result.
Always have at least one, if not both of the following in
place at all times:
• Side stow bracket completely engaged into stow
hook with stow pin A properly in place.
• Both pins C1, Figure 4-1 in upper and lower jib holes
properly in place through mating holes on boom tip.
CAUTION
Use caution when swinging jib to avoid unnecessary
impact with 1
st
section boom.
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