| Tweet |
Custom Search
|
|
|
||
 TM 55-1915-200-SDC
afloat, there is little danger of experiencing a negative metacentric height. The principal task, therefore, is to regain
buoyancy.
STEP FOUR
ELIMINATE OR REDUCE LIST. Since the SW Ballast Tanks 1 and 2 and the wing void tanks are not cross-
connected, it is expected that the ship will develop a 7-10list after damage to one of those tanks. Assuming that the
spaces above the main deck have been dewatered to the greatest possible extent, the next action should be to drain any
low spaces which may be PARTIALLY full. If circumstances permit, this procedure may be applied to diesel oil as well as
any damage water which may have entered these spaces. If any spaces below the main deck are COMPLETELY full,
they are best left alone for the time being.
After these preliminary operations have been carried out, attention may be turned to further reduction of list.
Since any list after damage will be due probably to shifting of solid weight rather than negative metacentric height, the
problem is a relatively simple one for the LSV. There are several methods of reducing list and these are indicated below
in the approximate order of desirability for the LSV. In general, any method which involves a lightening of displacement
should be favored over one which would increase displacement, particularly if structural damage has been severe or if
bad weather is prevailing at the time.
The order of procedure in this operation is to apply a transverse moment in the opposite direction to the un-
symmetrical load of EQUAL OR SMALLER magnitude. This may be done by:
a.
Emptying a tank on the low side into the sea. The moment correction is the figure given on the Liquid
Loading Diagram (assuming the tank was completely full and is completely drained).
b.
Shifting liquids from the low side to the high side. The transverse moment in this case is the sum of the
moment of the tank drained and the moment of the tank filled (assuming spaces are completely drained and completely
filled).
c.
Jettisoning topside weights on the low side. The transverse moment correction is the weight in tons
multiplied by its original distance from the centerline of the ship in feet.
d.
Shifting solid weights (cargo). The transverse moment is the weight in tons multiplied by the transverse
travel in feet.
CAUTION
Avoid shifting weight to a substantially higher level or flooding spaces above the main deck.
Excess weight high in the ship causes a rise in the center of gravity and subsequent degradation
of stability.
5-14
|
||
|
||
