Manitowoc Published 06-24-16, Control # 241-01 4-53
2250 OPERATOR MANUAL SETUP AND INSTALLATION
Raising and Lowering Gantry with Boom
Butt
Requirements for Raising and Lowering Gantry with
Boom Butt
See Figure 4-30 for more information.
o Crane is on a firm level surface.
o For truck cranes, the rotating bed and carrier is in line
with the boom butt and over the rear of the carrier.
o Boom butt is pinned to the crane as shown on the Boom
Rigging Drawing and is resting on the blocking at the
ground level.
o Physical boom stops are installed.
o Boom hoist wire rope is reeved properly through the
gantry and equalizer sheaves and is anchored to the
boom hoist drums as shown on the Boom Rigging
Drawing.
o Equalizer is pinned to the boom butt rails.
o Counterweights are either installed or removed.
o Assembly block, if installed, is kept on the ground while
raising and lowering the gantry.
Raising Gantry with Boom Butt
See Figure 4-30 for the following procedure.
1. Connect the crane setup remote control to the air valve
junction box on the left side of the rotating bed.
2. Turn on the cab power switch and start the crane’s
engine.
3. Select and confirm the setup mode with the crane mode
selector.
4. Fully extend the gantry cylinders with the switch on the
remote control to raise the gantry to the intermediate
position.
5. Raise the boom butt to 45° with the boom butt handling
cylinder (use the switch on the remote control).
6. Disengage the backhitch pins with the switch on the
remote control. Hold the backhitch pin switch in the
disengaged position until the contrasting paint color is
visible on the lower backhitch straps.
7. Raise the boom butt with the boom hoist control (boom
up). The boom butt will stop rising when the physical
boom stops are approximately 25 mm (1 in) from
bottoming out (see View A), and then the gantry should
rise.
NOTE: If the gantry does not rise when the boom butt
stops, depress the bypass switch in the crane cab.
Continue to raise the gantry with extreme caution.
Watch the boom stop tubes while the gantry rises.
The backhitch lower straps are painted a
contrasting color (see View B) to alert the operator
when the backhitch is approximately 152 mm (6 in)
from being fully extended.
Watch the backhitch while raising the gantry. Slow
down the boom hoist speed when the contrasting
color is reached.
DANGER
Tipping Hazard!
Avoid death, serious injury or tipping the crane. For a truck
crane, do not swing over the side of carrier rubber when
the counterweight is installed or when the gantry is
lowered with or without the counterweight installed.
DANGER
Crush Hazard!
Avoid serious injury. Do not attempt to raise the boom butt
with the boom hoist control until step 5
has been
performed. The boom butt will rise part of the way, and the
gantry will rise, then the boom butt and gantry will fall
violently.
CAUTION
Equipment Damage!
Do not allow the boom stop tubes to bottom out. Damage
to the boom stop tubes and the boom butt will occur.
CAUTION
Boom Butt Damage!
Use care while raising the boom butt. If either backhitch
pin fails to engage before the physical boom stops bottom
out, stop and correct the problem—damaged pin, or air/
electric fault.
Overtensioning the boom rigging can result in structural
damage to boom butt.
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