material for the one specified, you will have to find this
type of information concerning the relationship
between the two materials.
--Make full use of all available shapes, pieces, or
subassemblies. For example, you can make many
structures from standard rolled shapes and formed plate,
joined together by welding. You can save both time and
money by using available shapes.
Fabricating a Lever
The lever shown in figure 13-62 is made up of hubs
and a formed box section. The hubs are cut from
high-pressure tubing. The center box portion of the
lever is formed from
l/4-inch rolled steel plate. Each half of the section
is then bent to form a U-channel of the proper size and
shape. The component parts are then assembled and
joined by welding.
Fabricating a Bracket
The swinging knee bracket shown in figure 13-63
can be fabricated in several different ways just by using
various structural shapes. By changing the design
slightly, you can use a channel bar, an H-beam, or an
I-beam just as well as the angle bar shown in the
illustration. The cast bracket shown at the top of figure
Figure 13-63.--Cast swing knee bracket (top) and fabricated
13-63 weighed 570 pounds; the fabricated bracket made
swinging knee bracket.
to serve the same purpose weighed only 317 pounds and
cost 40 percent less than the cast bracket. As you can
see, the parts were cut from various standard shapes and
Fabricating a Clevis
then welded together.
The clevis shown in figure 13-64 is another
example of an item that can be made both lighter and
cheaper by fabrication rather than by casting. Also note
that the rough casting (top view) must be considerable
thicker than the fabricated clevis. Although some of the
excess metal would have to be machined off the rough
casting, the casting would still have to be thicker than a
fabricated clevis to serve the same purpose.
Fabricating Foundations and Supports
Bases, foundations, and supports are required for
numerous pieces of equipment and machinery aboard
ship. Figure 13-65 shows various bases and supporting
Figure 13-62.--Lever fabricated from high-pressure tubing
and rolled steel plate.
members fabricated from standard shapes.