Section VII. STABILITY REQUIRED AND STABILITY AVAILABLE

Custom Search

Section VI. EFFECTS OF DAMAGE

TM-55-1905-223-SDC Shipboard Damage Control Manual for Landing Craft Utility (LCU) NSN 1905-01-154-1191

Damage stability calculations

TM 55-1905-223-SDC

ship, since it does not provide a source of oxygen. The fumes from the explosion are frequently augmented by

smoke from ensuing fires. To enter and work in such compartments, personnel must wear oxygen-breathing

apparatus or an air-line hose mask.

Section VII.

STABILITY REQUIRED AND STABILITY AVAILABLE

5-25. STABILITY REQUIREMENTS. In determining the stability characteristics required to ensure that the

LCU will be seaworthy in the intact condition and capable of surviving the greatest practical amount of underwater

damage, the following factors, among others are considered:

Heeling effect of beam winds of typhoon force against the intact ship.

Residual stability after damage.

Heeling effect of unsymmetrical flooding after damage.

Reserve buoyancy after damage.

NOTE

For the LCU, the greatest practical amount of underwater

damage is limited by reserve buoyancy after damage.

e. The stability characteristics and the reserve buoyancy of these ships are such that a satisfactory

condition of stability and reserve buoyancy will exist after the flooding of any one compartment providing:

(1)

The specified limiting drafts are not exceeded before damage,

(2)

The height of center of gravity (KG) is kept at or below the limiting value, and

(3) A proper degree of watertight integrity is maintained. Specifically, the watertight doors to the

Bow Thruster Compartment at Frame 17and the door to the tunnel at Frame 25 must be closed and dogged.

5-26. STABILITY AVAILABLE. The LCU actually has excessive intact stability in all reasonable conditions

of loading. This is indicated by the high metacentric height, or GM, shown in one of the typical conditions of

loading. Because of this stability, the LCU can withstand an unusual amount of damage without assuming a

dangerously large angle of heel.

The short natural period of roll observed in the LCU is a function of its high initial stability. The motion in

a seaway is apt to be quick and uncomfortable. The effect of loading cargo high in the ship in an effect to

relieve this condition will be negligible for any practical arrangement of loading. A change in course or speed,

if tactically possible may reduce the amplitude of rolling.