TM 55-607/NAVSEA OP 3221 Rev 2
Table 5-1 Comparison of Approved Construction Techniques with Alternate Methods.
REGULATION
APPROVED CONSTRUCTION TECHNIQUES
ALTERNATE CONSTRUCTION TECHNIQUES FOR
NO.
AND MINIMUM LUMBER SIZES
OTHER LUMBER SIZES
46CFR146.29-11
Division bulkheads, tween-deck compartments, or
Uprights can be constructed of 4- by 4-inch lumber
(c) (19)
holds. Commercial 2-inch boards secured to 4- by 6-
when 4- by 6-inch lumber is not available. Spacing
inch uprights spaced 30 inches or less center-to-
must be reduced to 24-inch centers to provide com-
center. Random-width boards fitted edge-to-edge and
parable rigidity. Uprights can be constructed of 4- by
butt-to-butt.
4-inch lumber when 6- by 6-inch lumber is not avail-
Division bulkheads, lower holds. Commercial 2-inch
able. Spacing must be reduced to 16-inch centers to
boards secured to 6- by 6-inch uprights spaced 24
provide comparable rigidity.
inches or less on centers. Random-width boards fit-
ted edge-to-edge and butt-to-butt.
46CFR146.29-11
Dunnage. Not less than 1-inch commercial thickness
Use ofless than 1-inch lumberforgeneral dunnage is
(c) (20)
laid over tank tops, decks, or against bulkheads,
not permitted.
frames,ladders, or used for filling voids, or fitted
around cargo.
46CFR146.29-11
Partition bulkhead. Commercial 1-inch lumber of
Uprights can be constructed of 4- by 4-inch lumber
(c) (36)
widths not less than 4 inches, secured alternately on
when 2- by 4-inch lumber is not available. Upright
both sides of the uprights, and spaced not more than
spacing will not exceed 30 inches between centers.
6 inches apart. Uprights at least 2 by 4 inches and
spaced not more than 30 inches apart.
46CFR146.2 -11
9
Type A dunnage floor. Two layers of commercial 1-
Alternate construction not permitted.
(c) (63)
inch lumber of widths not less than 4 inches and
fitted as close as possible, edge-to-edge and butt-to-
butt. The top course is laid crosswise to the lower
course, or a single layer of 2-inch lumber of widths
not less than 6 inches is fitted as close as possible,
edge-to-edge and butt-to-butt. When 2-inch lumber
is used over hatch boards, it will be laid fore and aft.
46CFR146.29-11
Type B dunnage floor. One layer of commercial 1-inch
Alternate construction not permitted.
(c) (64)
lumber of widths not less than 4 inches fitted as close
as possible, edge-to-edge and butt-to-butt.
46CFR146.29-61
Stowage with nondangerous cargo in same hold.
Alternate construction not permitted.
(b)
When nondangerous cargo is to be stored adjacent to
exterior magazine, use wooden cargo batten of not
less than commercial 2- by 4-inch size, spaced not
more than 12 inches, center-to-center,and fitted
horizontally to the uprights that form the frame of
magazine.
46CFR146.29-75
Location of magazines and ammunition stowage. In
Minimum 4- by 4-inch uprights can be used when 4-
(a) (7)
insulated spaces normally comprising refrigerator
by 6-inch stock is not available. Spacing of uprights
spaces, pipes within compartment will be protected
must be reduced to 24 inches for comparable
by horizontal cargo battens of a size not less than
strength.
commercial 2 by 4 inches; spaced notmore than 12
inches apart, center-to-center; and secured to 4- by 6-
inch uprights spaced not more than 36 inches apart.
46CFR146.29-75
Construction of magazine to stow ammunition adja-
Deviations not permitted.
(b)(1),(2),(3)
cent to engineroom, boilerroom, or coal bunker bulk-
heads, or engineroom or boilerroom uptakes or cas-
ings. Construction of tight wooden temporary bulk-
head at least 1 foot off the permanent bulkhead,
uptakes, or casings, with the smooth side facing the
stowage of the explosives or ammunition.
When permanent bulkhead is smooth on cargo side,
Minimum of 4- by 4-inch uprights can be used when
commercial 2-inch boarding secured by 4- by 6-inch
4- by 6-inch lumber is unavailable; however, upright
uprights spaced not more than 30 inches apart on
spacing must not exceed 24 inches on tween decks or
tween or shelter deck, or 6- by 6-inch uprights spaced
16 inches in the lower holds. Headers and bearers are
not more than 24 inches apart in lower hold. A 2- by
optional. Two- by four-inch spacers are wedged to
6-inch bearer to carry the upright will be laid on the
overhead beams or ship's structures as required.
metal deck, and a 2- by 6-inch header will be fitted
against the underside of the overhead to receive top of
uprights. Suitable horizontal stringers will be fitted
between temporary and permanent bulkheads at top
and bottom, as well as intermediate stringers spaced
a maximum of 5 feet apart.
5-4
