requirements for fitting around plates and lift pads.
They also can be configured to provide access to
assembly angles between structures for wrapping
chains and wire rope during causeway beaching and
LST side-carry operations. Formerly, five types of
closures were needed to perform the necessary
functions. These were identified as DC1 through DC5.
The DC6 deck closure (fig. 10-14), with certain field
alterations, was designed to fulfill all closure
requirements and will replace the five closures
entirely when stocks of these have been depleted.
The H22 and H23 closure plates are used for
joining pontoons and for making bridge-to-wharf or
barge-to-wharf connections. The H17AF and H17AM
heavy-duty hinges are used to close the deck openings
formed by the hinges between the pontoon sections.
The closures (fig. 10-15), which are 20 wide and 24
1/4 long, are made from 1/2 steel plate and are used
in combinations to fit over and enclose the heavy-duty
hinges. Nonskid coating is applied on the top of the
closures to prevent slippage. The H22 and H23
closures are not included in the heavy-duty hinge set.
They are to be fabricated in the field as required.
BITTS AND CLEATS
Bitts and cleats are steel posts, or arms, to which
lines are secured. Structures to be side-carried should
have bitts and cleats, as well as all other deck fittings,
Figure 10-14.DC6 deck closure.
Figure 10-15.Closure plates H22 and H23.
bolted down on the launching angle side. A typical
cleat is shown in figure 10-16. The B1 all-purpose bitt
(fig. 10-17) consists of a single 4 diameter post that
is 13 long with a 6 diameter cap welded to a base
that has two drilled holes for A6B assembly bolts. A
1 1/2 diameter crossarm, 16 1/2 long, runs through
the post approximately 10 above the deck. The B1
can be used on all structures requiring a single bitt and
can be welded to the deck angles opposite the
launching angle side.
The B4 bitt (fig. 10-18) is the same as the B1 bitt
except for the base that has been designed for quick
positioning in the CP1 chain plate.
Figure 10-17.B1 all-purpose bitt.
Figure 10-18.B4 retractile bitt.