TM 55-607/NAVSEA OP 3221 Rev 2
Partial Stow Bulkheads. Normally it is advantageous to stow cargo in LASII lighters in full layers to
minimize time-consuming securing of the partial top layer. For many shipments, however, maximum space utilization
requires the stowage of a partial top layer. In these situations, securing of the partial top layer may be accomplished by
either of the following two structures:
(1) Step-down structure
. This structure, initially described
in paragraph 7-10,
is the simplest way
partial top layer. Cargo is stowed the required number of tiers high to a point specified on the preplan. At this point, two
4by 4-inch uprights are placed against each stack of unit loads, and laced from behind with 1by 6or 2by 4-inch TM 55-
607/NAVSEA OP 3221 Rev 2 material. Face boards are installed, prior to the placement of the uprights, when required
(usually for overhanging unit loads). Cargo stowage is then resumed on the other side of the structure at a reduced
height. Details of a step-down structure used to secure a partial top layer in a LASH lighter are illustrated in figure 10-13.
Step-down structures are not to be used when stepping down cargo more than one tier, nor when the cargo on the lower
side of the structure is of a lighter weight than the higher stowed cargo; instead, a diagonally braced bulkhead should be
installed as described below. In addition, it should be noted that a step-down structure requires about 4 inches of space
in the stow for insertion of uprights whenever it is used.
Figure 10-13. The step-down technique.