The speed with which corrective action is ap-plied to an engineering casualty is frequently of paramount importance. This is particularly true when dealing with casualties which affect propul-sion power, steering, and electrical power genera-tion and distribution. If casualties associated with these functions are allowed to spread, they may lead to serious damage to the engineering installa-tion, a damage which often cannot be repaired without loss of the ships operating availability. Where possible risk of permanent damage exists, the commanding officer has the responsibility for deciding whether or not to continue the opera-tion of the equipment under casualty conditions. The operation of equipment under casualty con-trol can be justified only where the risk of even greater damage, or loss of the ship, may be in-curred by immediately securing the affected unit.

Whenever there is no probability of greater risk, the proper procedure is to secure the malfunctioning unit as quickly as possible even though considerable disturbance to the ships operations may occur. Although speed in control-ling a casualty is essential, action should never be undertaken without accurate information, otherwise the casualty may be mishandled, and irreparable damage and possible loss of the ship may result. War experience has shown that the cross-connecting of an intact system with a partly damaged one should be delayed until it is certain that such action will not jeopardize the in-tact system. Speed in the handling of casualties can be achieved only by a thorough knowledge of the equipment and associated systems, and by thorough and repeated training in the routine re-quired to handle specific predictable casualties.

PHASES OF CASUALTY CONTROL

The handling of any casualty can usually be divided into three phases: (1) limitation of the ef-fects of the damage, (2) emergency restoration, and (3) complete repair.

The first phase is concerned with the im-mediate control of the casualty so as to prevent further damage to the unit affected and to pre-vent the casualty from spreading.

The second phase consists of restoring, as far as practicable, the services which were interrupted as a result of the casualty. For many casualties, the completion of this phase eliminates all other operational handicaps, except for the temporary loss of the standby units-which lessens the ships ability to withstand additional failures. If no damage to machinery occurred, this phase usually completes this phase of casualty control. The third phase of casualty control consists of making repairs which completely restore an in-stallation to its original condition.