Principles of naval engineering - Historic Naval Ships Association

PRINCIPLES OF NAVAL ENGINEERINGconditions X-RAY, YOKE, and ZEBRA; it alsoapplies to vital valves that, if secured, wouldimpair the mobility and fire protection of theship. These items are secured only as necessaryto control damage or contamination and toeffect repairs to the units served.CIRCLE WILLIAM fittings, marked with ablack W in a black circle, are normally keptopen (as WILLIAM fittings are) but must besecured as defense against nuclear, biological,or chemical attack.INVESTIGATION OF DAMAGEThe DC A must be given all available informationconcerning the nature and extent of damageso that he will be able to analyze the damageand decide upon appropriate measures of control.The repair parties that are investigatingthe damage at the scene are normally in thebest position to give dependable information onthe nature and extent of the damage. All repairparty personnel should be trained to makeprompt, accurate, and complete reports to damagecontrol central. Items that should normallybe reported to damage control central include:1. Description of important things seen,heard, or felt by personnel.2. Location and nature of fires, smoke, andtoxic gases.3. Location and nature of progressive flooding.4. Overall extent and nature of flooding.5. Structural damage to longitudinal strengthmembers.6. Location and nature of damage to vitalpiping and electrical systems.7. Local progress made in controlling fire;halting flooding; isolating damaged systems; andrigging jury piping, casualty power, and emergencycommunications.8. Compartment-by-compartment informationon flooding, including depth of liquid in eachflooded compartment.9. Condition of boundaries (decks, bulkheads,and closures) surrounding each flooded compartment.10. Local progress made in reclaiming compartmentsby plugging, patching, shoring, andremoving loose water.11. Areas in which damage is suspected butcannot be reached or verified.The DCA must ascertain just what informationthe commanding officer desires concerningthe extent of the damage incurred and thecorrective measures taken.The DCA must alsofind out how detailed the information to the COshould be and when it is to be furnished. Withthese guidelines in mind, the DCA must sift allinformation coming into damage control centraland pass along to the bridge only the type ofinformation that the CO wants to have.CORRECTIVE MEASURESMeasures for the control of damage may bedivided into two general categories: (1) overallship survival measures, and (2) immediatelocal measures.OVERALL SHIP SURVIVAL MEASURESOverall ship survival measures are thoseactions initiated by damage control central forthe handling of list, trim, buoyance, stability,and hull strength. Operations in this categoryhave five general objectives: improving GMand overall stability, correcting for off-centerweight, restoring lost freeboard and reservebuoyancy, correcting for trim, and relievingstress in longitudinal strength members.Improving GMand Overall StabilityThe measures used to improve GM and overallstability in a damaged ship include (1)suppressing free surface, (2) jettisoning topsideweights, (3) ballasting, (4) lowering liquidor solid weights, and (5) restoring boundaries.Correcting forOff- Center WeightOff-center weight may occur as the resultof unsymmetrical flooding or as the result ofCorrectingan athwartship movement of weight.for off-center weight may be accomplished by(1) pumping out off-center flooding water, (2)pumping liquids across the ship, (3) counterflooding,(4) jettisoning topside weights fromthe low side of the ship, (5) shifting solidweights athwartships, and (6) pumping liquidsoverboard from intact wing tanks on the lowside.Restoring Lost Freeboardand Reserve BuoyancyRestoring lost freeboard and reserve buoyancyrequires the removal of large quantities64