PRINCIPLES OF NAVAL ENGINEERING 



conditions X-RAY, YOKE, and ZEBRA; it also 

 applies to vital valves that, if secured, would 

 impair the mobility and fire protection of the 

 ship. These items are secured only as neces- 

 sary to control damage or contamination and to 

 effect repairs to the units served. 



CIRCLE WILLIAM fittings, marked with a 

 black W in a black circle, are normally kept 

 open (as WILLIAM fittings are) but must be 

 secured as defense against nuclear, biological, 

 or chemical attack. 



INVESTIGATION OF DAMAGE 



The DC A must be given all available informa- 

 tion concerning the nature and extent of damage 

 so that he will be able to analyze the damage 

 and decide upon appropriate measures of con- 

 trol. The repair parties that are investigating 

 the damage at the scene are normally in the 

 best position to give dependable information on 

 the nature and extent of the damage. All re- 

 pair party personnel should be trained to make 

 prompt, accurate, and complete reports to dam- 

 age control central. Items that should normally 

 be reported to damage control central include: 



1. Description of important things seen, 

 heard, or felt by personnel. 



2. Location and nature of fires, smoke, and 

 toxic gases. 



3. Location and nature of progressive flood- 

 ing. 



4. Overall extent and nature of flooding. 



5. Structural damage to longitudinal strength 

 members. 



6. Location and nature of damage to vital 

 piping and electrical systems. 



7. Local progress made in controlling fire; 

 halting flooding; isolating damaged systems; and 

 rigging jury piping, casualty power, and emer- 

 gency communications. 



8. Compartment-by-compartment informa- 

 tion on flooding, including depth of liquid in each 

 flooded compartment. 



9. Condition of boundaries (decks, bulkheads, 

 and closures) surrounding each flooded compart- 

 ment. 



10. Local progress made in reclaiming com- 

 partments by plugging, patching, shoring, and 

 removing loose water. 



11. Areas in which damage is suspected but 

 cannot be reached or verified. 



The DCA must ascertain just what informa- 

 tion the commanding officer desires concern- 

 ing the extent of the damage incurred and the 



corrective measures taken. The DCA must also 

 find out how detailed the information to the CO 

 should be and when it is to be furnished. With 

 these guidelines in mind, the DCA must sift all 

 information coming into damage control central 

 and pass along to the bridge only the type of 

 information that the CO wants to have. 



CORRECTIVE MEASURES 



Measures for the control of damage may be 

 divided into two general categories: (1) over- 

 all ship survival measures, and (2) immediate 

 local measures. 



OVERALL SHIP SURVIVAL MEASURES 



Overall ship survival measures are those 

 actions initiated by damage control central for 

 the handling of list, trim, buoyance, stability, 

 and hull strength. Operations in this category 

 have five general objectives: improving GM 

 and overall stability, correcting for off-center 

 weight, restoring lost freeboard and reserve 

 buoyancy, correcting for trim, and relieving 

 stress in longitudinal strength members. 



Improving GM 



and Overall Stability 



The measures used to improve GM and over- 

 all stability in a damaged ship include (1) 

 suppressing free surface, (2) jettisoning top- 

 side weights, (3) ballasting, (4) lowering liquid 

 or solid weights, and (5) restoring boundaries. 



Correcting for 

 Off- Center Weight 



Off-center weight may occur as the result 

 of unsymmetrical flooding or as the result of 

 an athwartship movement of weight. Correcting 

 for off-center weight may be accomplished by 

 (1) pumping out off-center flooding water, (2) 

 pumping liquids across the ship, (3) counter- 

 flooding, (4) jettisoning topside weights from 

 the low side of the ship, (5) shifting solid 

 weights athwartships, and (6) pumping liquids 

 overboard from intact wing tanks on the low 

 side. 



Restoring Lost Freeboard 

 and Reserve Buoyancy 



Restoring lost freeboard and reserve buoy- 

 ancy requires the removal of large quantities 



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