5-18. LIMITING DECK LOADS. Addition of topside weight reduces stability. Deck loads in excess of the normal
loading of the ship (as described in the Trim and Stability Booklet) tend to impair the ability of the ship to absorb damage.
Officers should weigh the added risk before permitting these limiting deck loads to be exceeded.
5-19. SELF-INFLICTED DAMAGE. To afford access and provide for operating the ship, watertight boundaries of
above-water compartments are pierced by such openings as doors, hatches, and scuttles. Maximum reserve buoyancy
can be realized only when all such openings are properly and tightly closed. Reserve buoyancy may be impaired by the
crew's actions as well as by accidental or battle damage. The following examples show actions by the crew which lessen
the watertight integrity of the ship:
Poor maintenance, resulting in lack of tightness in watertight boundaries, closures, or fittings within the
Failure to close properly such fittings as doors and hatches, which violates watertightness.
Improper, insufficiently rigid damage control classification of fittings.
5-20. ADDITIONAL TOPSIDE WEIGHT. The discussions that follow are relative to additional topside weight and its
effect on overall stability:
Emergency topside loading of this ship resulting from deck cargo, taking aboard large numbers of
survivors, or icing-up of rigging and superstructure will impair overall stability because of the consequent rise in center of
gravity as well as loss of freeboard. This will reduce the ship's seaworthiness and ability to withstand damage.
Decisions to carry emergency deck cargo must be taken with full understanding of the dangers involved
and the increased hazard to the ship in the event of damage. Location and magnitude of additional weights can be used
to calculate net decrease in stability resulting from a specified deck load.
It is possible that the ship may be called upon to pick up large numbers of survivors. The resulting
additional topside weight can be a matter of grave concern, particularly if the survivors all come topside and go to one
side of the ship simultaneously.
Topside structure and rigging ices up in frigid weather, most heavily within 100 miles of the coast. The
resulting reduction in stability makes it necessary to maintain the ship in the most favorably ballasted condition. Icing is
combated by using jets of steam and/or hot salt water, as well as mauls and axes. The heavy weight increase high in the
ship will cause an appreciable rise in the center of gravity. If icing is severe, the ship may have negative initial stability
and will loll or capsize.