CRANES
CHAPTER 12
AND ATTACHMENTS
Cranes and attachments are essential to the support
of Naval Construction Force (NCF) operations. Lifting
heavy objects, loading and unloading construction
materials, excavating earthwork materials, and driving
and extracting piles are typical tasks accomplished by
the use of cranes and attachments.
Cranes and attachments procedures are a complex
set of characteristics. Proper and efficient operation of
cranes and their attachments requires more knowledge
and skill than for any other piece of construction
equipment you will operate.
NOTE: You must always be exceptionally safety
conscious when working on or around crane operations
of any type.
This chapter covers the characteristics and basic
principles of operations of cranes and attachments. By
reading the operator’s manual and attending crane school,
you can obtain detailed information about crane
operations.
CRANES
Cranes are classified as weight-handling equip-
ment and are designed primarily to perform
weight-lifting and excavating operations under varied
conditions. To make the most efficient use of a crane,
you must know their capabilities and limitations.
TYPES OF CRANES
Cranes have evolved from many designs to satisfy
the needs of construction and industrial operations.
Operational characteristics of all cranes are basically the
same. Although the superstructure is about the same on
all makes and models of mobile cranes, the carrier, or
mounting, may be one of three types: crawler, truck, or
wheel (fig. 12-1).
Crawler-Mounted Cranes
The crawler-mounted crane is categorized under the
42-00000 USN number registration series. The
crawler-mounted crane is slower and less mobile than
the truck-mounted crane; however, the crawler-mount
crane provides a stable base for operation of the
revolving superstructure.
The travel unit of the crawler crane is shown in
figure 12-2.
The travel unit includes the base,
travel gears, clutches, travel brakes, sprockets,
rollers, crawler chains, and crawler treads. The
revolving superstructure rotates on the turntable
(fig. 12-3).
Figure 12-1.-Crane carrier mountings.
Figure 12-2.—Crawler crane travel unit.
Figure 12-3.—Turntable assembly.
12-1
