A25317-A-1119
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Owner's Manual for Thern 5FT20 and 5FT25 Captain Series Stationary Davit Cranes
Figure 1 – Crane Lock
Figure 2 – Lynch Pins
1.2
Assembling the Crane
When installing the ratchet jack, support the end of the boom so the boom does
not fall and the ratchet jack does not swing causing damage or injury.
When installing the boom extension, hold the boom extension securely so it does
not slide abruptly in or out of the boom causing damage or injury.
1.2.1
STUDY PARTS DRAWINGS to understand how the crane is assembled.
See pages 19-20.
1.2.2
LUBRICATE THE ENTIRE CRANE as you assemble it. Refer to the
Lubrication Instructions in Section 3.2
1.2.3
INSTALL THE BASE. See Section 1.1 for additional information and crane
overturning moments and mounting bolt reaction forces.
1.2.4
ENGAGE THE CRANE LOCK to secure the mast and prevent it from
rotating during assembly. See Figure 1.
1.2.5
FASTEN THE BOOM to the mast using the pin and lynch pin provided.
For manual winch models, install a sheave on the boom pin as you
fasten the boom to the mast.
1.2.6
INSTALL THE RATCHET JACK.
a
ENSURE THAT BOTH THREADED ENDS of the ratchet jack are an equal
distance out of the jack when assembled to the crane. If threaded ends are not
equal, the crane boom will not be able to operate in its full range of motion.
b
FASTEN ONE END OF THE RATCHET JACK to the mounting ear on the
boom with the clevis and lynch pin provided. Carefully pivot the boom until the
other end of the ratchet jack aligns with the mounting ear on the mast, and secure
using the clevis pin and lynch pin provided. See Figure 2.
1.2.7
ADJUST THE BOOM with the ratchet jack so the boom is horizontal.
1.2.8
SLIDE THE BOOM EXTENSION into the boom, and secure in place with the
clevis pin and lynch pin provided.
Make sure the boom extension is
positioned correctly with auxiliary mounting holes toward the ground.
1.2.9
FASTEN THE WINCH to the appropriate mounting plate. Manual winches
should be installed on the mast. Power winches should mount on the boom.
Make sure the winch is positioned correctly with winch drum facing
towards the load.
On some models you will need to use a winch adapter
plate to fasten the winch to the crane. See pages 19-21.
1.2.10
INSTALL THE WINCH HANDLE on hand winches, or connect electric
current on power winches. Refer to instructions in the Winch Owner’s Manual.
1.2.11
INSTALL THE WIRE ROPE.
a
REMOVE ROPE KEEPER PIN at the sheave to allow rope to be installed.
b
PASS THE WIRE ROPE over the sheave and reinstall rope keeper pin to
prevent the rope from escaping the sheave rope groove.
d
ANCHOR THE WIRE ROPE to the winch drum and wind 4 wraps of wire
rope onto the drum to act as anchor wraps. Refer to the instructions in the
Winch Owner’s Manual.
1.2.12
MAKE SURE ALL FASTENERS are tightened with all clevis and lynch
pins in place to prevent components from shifting during use.
1.2.13
INSTALL UPPER TRAVEL LIMIT SWITCH when supplied with power
winches as directed in supplemental instructions provided with limit switch kit.
Important!
• Inspect the crane during
assembly according to the
Instructions for Periodic
Inspection. This will give
you a record of the condition
of the crane with which to
compare future inspections.
• Save all boxes and crates
that the crane was shipped
in, use them again if you
need to repackage the crane.
• Contact the factory
immediately if any parts are
missing or damaged.
• Do not overtighten
fasteners, this may strip
threads or cause damage
to other parts.
