TM 55-07/NAVSEA OP 3221 Rev 2
7-6. Division Bulkheads
When the quantity of explosives stowed is insufficient to fill the hold or compartment completely, general cargo may be
loaded in the remaining area, provided the explosives are completely separated from the general cargo by means of a
division bulkhead, shown in figure 7-19. Federal regulations (46CFR146.29-11) currently require that commercial 2-inch
boarding be secured on 4by 6-inch uprights spaced not to exceed 30 inches center-to-center for tween-deck
compartments or holds and on 6by 6-inch uprights spaced not to exceed 24 inches center-to-center for lower holds.
However, general shortages of 4by 6or 6by 6-inch stock often necessitate use of 4by 4-inch uprights in construction of
the division bulkhead. Special exemptions are required in accordance with 46CFR, 146.02-25 and 49CFR107. Boarding
may be of random widths, although 2by 12-inch lumber is preferred. A smooth surface, formed by edge-to-edge and
butt-to-butt fitting of the boarding, always faces the explosives stowage. When use of 4by 4inch uprights is necessary,
spacing must not exceed 24 inches on the tween decks or 16 inches in the lower holds. Construction details and
recommended spacing with 4by 4-inch uprights are summarized in table 5-1.