Removal and Replacement of Components

On the other hand, if the pitch pointer and the scale difference is less than a 1/16 of an inch or the greater than reading is related to thermal growth or contraction, then the scale can be moved to match the pointer’s position. The only drawback to adjusting the scale to match the pointer is that an electronic alignment (calibration) must be performed ELECTRONIC ALIGNMENT.— The electronic alignment procedures differ depending on the ship class. But, one thing will always be the same. To accomplish any of these procedures, the ship must be in dry dock or you will require the assistance of a diver. All adjustments made to align the mechanical (actual) pitch and electronic display indications must be verified with the actual blade position on the propeller hub. There is one electronic alignment procedure (electronic pitch indicating [EPI] system calibration) on the DDG-51 class that can only be accomplished when the ship is in dry dock. REMOVAL AND REPLACEMENT OF COMPONENTS The CRP/CPP system seldom requires the removal or replacement of components. However, there is one component that you will be required to replace—the electrohydraulic servo valve. As previously discussed, this valve is in constant use and its probability of failure is much higher than any other component in the system. There is only one other set of components that you will need to remove frequently—the system’s filters. In fact, you will need to remove these filters even more frequently than the electrohydraulic servo valve. This is because you will need to remove the filters for periodic cleaning according to the PMS. Of course, you will also need to remove them in the event of a casualty. SUMMARY In this chapter, we have discussed many of the factors that affect GTE performance, power train operation and maintenance, and propulsion systems. As you prepare for advancement, you must continue to learn and increase both your leadership skills and technical expertise. You must be prepared to train and supervise your subordinates. Read the various reference materials cited in this chapter to increase your understanding of the information that was presented. 3-19