change when rotating a load from one quadrant to
another. This information is provided on the crane load
LATTICE BOOM CRANE
The major components of a lattice boom crane are
shown in figure 12-11.
Inspecting each of these
components is part of the operators prestart inspection.
The lattice boom supports the working load and is
the most common boom used in the NCF. It is used on
all types and makes of cranes and is mounted at the boom
butt on the revolving superstructure. The basic boom
consists of the boom butt and boom tip, and the length
is increased by adding boom extensions.
Lattice boom sections are made of lightweight, thin
wall, high strength alloy tubular or angle steel and are
designed to take compression loads. The most common
boom is tubular. Terminology of a lattice boom section
is shown in figure 12-12.
Manufacturers have set a zero tolerance on rust,
bent lacings or cords, cracked welds, and other problems
that affect the strength of the lattice boom. This zero
tolerance requires crane crews to use extreme care when
handling unused sections with forklifts, storing unused
sections away from traffic areas, transporting and
securing sections on tractor-trailers, and preventing
equipment or obstacles from running into the boom
while mounted on the crane during transport,
performing operations, or when parked.
As outlined in the Management of Weight-Handling
Equipment, Maintenance and Certification, NAVFAC
P-307, all lattice boom cranes with structural damage to
the main cords of the boom must be immediately
Figure 12-11.Lattice boom crane components.