Principles of naval engineering - Historic Naval Ships Association

CHAPTER 4PREVENTIVE AND CORRECTIVE DAMAGE CONTROLAboard ship, the overall damage and casualtycontrol function is composed of two separate butrelated phases: the engineering casualty controlphase and the damage control phase. The engineeringofficer is responsible for both phases.The engineering casualty control phase isconcerned with the prevention, minimization, andcorrection of the effects of operational and battlecasualties to the machinery, electrical systems,and piping installations, to the end that all engineeringservices may be maintained in a state ofmaximum reliability under all conditions of operation.Engineering casualty control is handledalmost entirely by personnel of the engineeringdepartment.The damage control phase, on the other hand,involves practically every person aboard ship.The damage control phase is concerned with suchthings as the preservation of stability and watertightintegrity, the control of fires, the control offlooding, the repair of structural damage, and thecontrol of nuclear, biological, and chemicalcontamination. Although under the control of theengineer officer, damage control is an all-handsresponsibility.This chapter presents some basic informationon the principles of the damage controlphase of the damage and casualty control function.Information on engineer ing casualty controlis not included here; any such information wouldbe relatively meaningless without a considerablebackground knowledge of the normal operatingcharacteristics of shipboard machinery andequipment.PREPARATIONS TO RESIST DAMAGENaval ships are designed to resist accidentaland battle damage. Damage resistant features includestructural strength, watertight compartmentation,stability, and buoyancy. Maintainingthese damage resistant features and maintaininga high state of material and personnel readinessbefore damage is far more important for survivalthan are any damage control measuresthat can be taken after the ship has been damaged.It has been said that 90 percent of thedamage control needed to save a ship takes placebefore the ship is damaged and only 10 percentcan be done after the damage has occurred. Inspite of all precautions and all preparatorymeasures, however, the survival of a ship sometimesdepends upon prompt and effective damagecontrol measures taken after damage has occurred.It is essential, therefore, that all shipboardpersonnel be trained in damage control procedures.The maintenance of watertight integrity is avital part of any ship's preparations to resistdamage. Each undamaged tank or compartmentaboard ship must be kept watertight if floodingis not to be progressive after damage. Watertightintegrity can be lost in a number of ways.Failure to secure access closures and impropermaintenance of watertight fittings and compartmentboundaries, as well as external damage tothe ship, can cause loss of watertight integrity,a thorough system of tests and inspections isprescribed. The condition of watertight boundaries,compartments, and fittings is determinedby visual observation and by various tests, includingchalk tests and air tests. All defectsdiscovered by any test or inspection must beremedied immediately.For most ships, a mandatory schedule of watertightintegrity tests and inspections is prepared.This schedule informs each ship of thecompartments subject to test and/or inspection,specifying which type of test or inspection shallbe applied. Ships not provided with such a scheduleare nevertheless required to make inspectionsof important watertight boundaries as requiredby chapter 9290 of the of Naval ShipsTeclinical Manual.61