Manitowoc 2250 User Manual

Reference Only
SETUP AND INSTALLATION 2250 OPERATOR MANUAL
4-50
Published 06-24-16, Control # 241-01
GANTRY RAISING AND LOWERING (WITH
BOOM BUTT HANDLING CYLINDER)
General
This section contains the gantry raising and lowering
instructions for cranes equipped with a two-piece boom butt
and boom butt handling cylinder.
Figure 4-30
shows a crawler crane. These procedures also
apply to truck cranes.
Gantry raising and lowering requires two people:
• One to operate the boom hoist control in the crane cab.
• A second to operate the remote controls from the ground
level, to observe the raising or lowering procedure, and
to provide the necessary signals to the operator in the
cab
These personnel shall read and become thoroughly familiar
with the instructions section before attempting any
procedure. Contact the Manitowoc Crane Care Lattice Team
for assistance if any procedure is not understood.
The gantry assembly has a telescopic backhitch, which
provides the following three positions (Figure 4-30
):
• FULLY RAISED—position for all the load handling
operations
• INTERMEDIATE—fully extended position of the gantry
cylinders
The gantry cylinders must be used to partially raise and
fully lower the gantry. The boom hoist rigging is used to
raise and lower the gantry from or to the extended
position of the cylinders.
• FULLY LOWERED—transporting the crane and for
handling some boom lengths (see Boom Rigging
Drawing for the boom handling conditions)
The gantry cylinders, backhitch pins, and boom butt handling
cylinder are controlled with switches on the crane setup
remote control. See Section 3 for the identification and
location of all the operating controls.
To raise and lower the gantry, the Setup mode must be
selected and confirmed.
In the Setup mode, the crane’s normal automatic boom stop
is bypassed and the setup boom stop is activated. The setup
limit switch (Figure 4-30
, View A) stops the boom butt when
the boom stop tubes are approximately 25 mm (1 in) from
bottoming out (boom butt at approximately 89°).
When the boom stop tubes are approximately 25 mm (1 in)
from bottoming out, the gantry should be fully raised and you
should be able to engage/disengage the backhitch pins with
the corresponding switch on the remote control.
If for some reason the backhitch pins cannot be engaged/
disengaged when the boom stop tubes are approximately 25
mm (1 in) from bottoming out, it will be necessary to bypass
the setup boom stop and to boom up slightly.
CAUTION
Equipment Damage Hazard!
Do not allow the boom stop tubes to bottom out. Damage
to the boom stop tubes and the boom butt will occur.
CAUTION
Crush Hazard!
The gantry can fall onto the personnel. Avoid personal
injury. Do not raise or lower the gantry until all personnel
are off the top of the crane and counterweights.
Do not lift loads, including the assembly block, when the
gantry is in the intermediate position. The gantry will rise,
allowing the boom butt and the load to fall violently.

Manitowoc 2250 Specifications

General

Brand	Manitowoc
Model	2250
Category	Construction Equipment
Language	English