Chapter 4- PREVENTIVE AND CORRECTIVE DAMAGE CONTROL 



of weight. In general, the most practicable way 

 of accomplishing this is to restore watertight 

 boundaries and to reclaim compartments by 

 pumping them out. Any corrective measure 

 which removes weight from the ship contributes 

 to the restoration of freeboard. 



Correcting for Trim 



The methods used to correct for trim after 

 damage include (1) pumping out flood water, (2) 

 pumping liquids forward or aft, (3) counter- 

 flooding the high end, (4) jettisoning topside 

 weights from the low end, (5) shifting solid 

 weights from the low end to the high end, and 

 (6) pumping liquids over the side from intact 

 tanks at the low end. The first of these methods— 

 that is, pumping out flood water— is in most 

 cases the only truly effective means of correct- 

 ing a severe trim. 



The correction of trim is usually secondary 

 to the correction of list, unless the trim is so 

 great that there is danger of submerging the 

 weather deck at the low end. 



Relieving Stress in 

 Longitudinal Strength Members 



When a ship is partially flooded, the longi- 

 tudinal strength members are subject to great 

 stress. In cases where damage has carried 

 away or buckled the strength members amid- 

 ships, the additional stress imposed by the 

 weight of the flooding water may be enough to 

 cause the ship to break up. The only effective 

 way of relieving stress caused by flooding is 

 to remove the water. Other measures, such as 

 removing or shifting weight, may be helpful 

 but cannot be completely effective. In some in- 

 stances, damaged longitudinals may be strength- 

 ened by welding. 



IMMEDIATE LOCAL MEASURES 



Immediate local measures are those actions 

 taken by repair parties at the scene of the dam- 

 age. In general, these measures include all 

 on-scene efforts to investigate the damage, to 

 report to damage control central, and to ac- 

 complish the following: 



1. Establish flooding boundaries by select- 

 ing a line of intact bulkheads and decks to which 

 the flooding may be held and by rapidly plugging, 

 patching, and shoring to make these boundaries 

 watertight and dependable. 



2. Control and extinguish fires. 



3. Establish secondary flooding boundaries 

 by selecting a second line of bulkheads and decks 

 to which the flooding may be held if the first 

 flooding boundaries fail. 



4. Advance flooding boundaries by moving 

 in toward the scene of the damage, plugging, 

 patching, shoring, and removing loose water. 



5. Isolate damage to machinery, piping, 

 and electrical systems. 



6. Restore piping systems to service by 

 the use of patches, jumpers, clamps, couplings, 

 etc. 



7. Rig casualty power. 



8. Rig emergency communications and 

 lighting. 



9. Rescue personnel and care for the wound- 

 ed. 



10. Remove wreckage and debris. 



11. Cover or barricade dangerous areas. 



12. Ventilate compartments which are filled 

 with smoke or toxic gases. 



13. Take measures to counteract the effects 

 of nuclear, biological, and chemical contamina- 

 tion or weapons. 



Immediate local measures for the control 

 of damage are of vital importance. It is not 

 necessary for damage control central to decide 

 on these measures; rather, they should be car- 

 ried out automatically and rapidly by repair 

 parties. However, damage control central should 

 be continuously and accurately advised of the 

 progress made by each party so that the efforts 

 of all repair parties may be coordinated to the 

 best advantage. 



PRACTICAL DAMAGE CONTROL 



Both the immediate local measures and the 

 overall ship survival measures have, of course, 

 the common aim of saving the ship and restoring 

 it to service. The following subsections deal 

 with the practical methods used to achieve this 

 aim: controlling fires, controlling flooding, re- 

 pairing structural damage, and restoring vital 

 services. 



It should be noted that controlling the effects 

 of nuclear, biological, and chemical warfare 

 weapons or agents may in some situations take 

 precedence over other damage control mea- 

 sures. Because of the complex nature of NBC 

 defense, this subject is treated separately in a 

 later section of this chapter. 



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