7. Maintenance on cranes should be performed
only by formally qualified personnel, unless authorized
by an authorizing officer on a single case basis for
unusual repairs.
You must do all the maintenance requirements
according to the instructions provided on the applicable
MRCs. If the MRCs do not exist for a particular piece
of equipment, your supervisor or you should institute
interim maintenance according to the manufacturer’s
recommendations.
The following maintenance items should be
included in the crane PMS package:
l Lubrication
l Safety inspection
l Lube oil maintenance
l Wire rope
l Brakes
l Instrumentation
l Electrical
For more general information on crane
maintenance, repairs, and inspections, read NSTM,
Chapter 589, “Cranes.”
Your ship should have a copy
of the manufacturer’s technical manual for in-depth
individualized information of your ship’s crane.
DUMBWAITERS
A dumbwaiter is a semiautomatic electro-
mechanical hoist operating in a structural trunk. The car
of a dumbwaiter is arranged to carry ship’s stores of
varying weights and package sizes. Figure 8-10
illustrates the parts and controlling mechanisms of a
dumbwaiter.
You should inspect the dumbwaiter car and hoist
every 3 months. Check the condition of the load cable
(it could be a chain or wire rope cable), motor brake,
friction clutches, overtravel limit devices, door interlock
control switches, and safety devices. You must follow
the manufacturer’s manual or the procedures specified
by the PMS when making repairs. You are required to
complete a PQS for this equipment. For more general
information, read NSTM, Chapter 572, “Shipboard
Stores and Provision Handling.”
Figure 8-10.—Dumbwaiter.
ESCALATORS
Only aircraft carriers have escalators aboard, and
each aircraft carrier has two escalators. Each is chain
driven by a horizontally mounted worm gear machine.
An escalator can operate in either direction and is
designed to operate at a speed of 120 feet per minute,
carrying flight personnel at the rate of 44 persons per
minute. For full details of this equipment, read NAVSEA
0316-LP-020-7000, Shipboard Escalators (Aircraft
Carriers). You must complete the required PQS for this
equipment. When making repairs, follow the necessary
safety precautions and the procedures specified by the
manufacturer’s manual or the PMS.
SUMMARY
This chapter has provided you with some general
information on the maintenance and repair of auxiliary
machinery. For you to do your job properly, you must
be totally familiar with each piece of machinery; you
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