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Reports Reports from the team leader require the completion of the record log book for each component and the proper closeout of that log before stowage in the engine containers. All entries should be complete up to the time of changeout, checked for correctness, and signed off by the engineer officer. The SSE containers that were inventoried on arrival are to be inventoried again at completion for reissue to the next user. The engineer officer and main propulsion assistant are required by squadron directives to notify the proper people of any irregularities at the completion of the changeout. If lessons were learned because of the changeout, notify the people concerned. Any unique or suspect occurrences could be very valuable sources of information.

LESSONS LEARNED The following section describes some lessons learned during engine changeouts.

Pierside Changeouts Since the first changeout on the SPRUANCE class ships, problem areas and past discrepancies during pierside changeouts have been numerous. Problems such as location of the equipment and containers at pierside can delay the job. When equipment or containers are placed out of the crane's reach, the delay is costly and frustrating.

Some changeouts have been hampered by crane service that was not totally dedicated to the job of engine changeout. Many hours were lost awaiting the crane. Crane services are needed full time throughout the changeout. All concerned personnel should realize that to complete the changeout on time, the crane and operator's services are required the full 36 hours. Engine lifting is not all that is required of the crane. Every component of the rail system plus all the lift fixtures require crane services. The crane will be in constant use, especially when the personnel basket is used. Personnel are also required to check the engine's guide rollers in the permanently mounted guide tracks for freedom of movement.

At times, inclement weather has caused difficulties. This is especially true in an unprotected harbor where the water roughness or groundswells have had an effect on the movement of the ship at the pier. Therefore, to facilitate the changeout, the ship must be pierside and should be inboard of any other ship( s) present. Sometimes, floating cranes have been used, but the evolution was still hampered by the elements.

Tenderside Changeouts Tenderside changeouts have problems of a different nature. The tender is a stationary platform. The ship must be moved and positioned around the tender to help the crane service. The SSE containers, when stored on the tender and within reach of the crane, were on the 03 or 04 level. This made travel to and from the containers very difficult.

Horizontal Rail Systems The horizontal rail systems also have had problems. Some of these problems are attributed to a lack of inspection before use.

- To ensure safe and proper handling of the engine and/ or components by the crane operator, have the ship ballasted to remove any listing.

-Dry trunnion bearings on rail stanchions are difficult to turn. This is especially true if the adjustment ring holes have been elongated. Therefore, a grease lubricant (MLG-G-10924 or equivalent) should be used to lubricate the adjustment ring.

-The horizontal rail flanges, when not properly lined up, will make the gas generator separation hazardous. Misaligned rail flanges may cause the gas generator position to shift and possibly damage the C-sump air seals. On mating up gas generator to power turbine, the No. 6 bearing cage can be damaged when the front-frame lift fixture roller crosses the forward flange in the rail. This makes the gas generator shift weight.

-The adjustable rollers on the lift fixtures are susceptible to corrosion. Corrosion may cause the roller to jam into one position. If not properly lubricated before use, the adjustable rollers on the lift fixtures are capable of freezing up. This makes it impossible to center the engine.

-When not properly serviced and filled with cylinder oil, the hydraulic support mechanism for the compressor front frame will not permit the jack to be

extended far enough to support the front frame for removal of the support pins.

-Ensure all feeder rail sections are installed and aligned before checking the travel of the system with a hand-held roller.

-If a bearing failure necessitates an engine changeout, a complete flushing of the lube oil system is required.

Tag and Bagging Practices There is evidence that tagging and bagging practices on engine changeouts have not been followed to the letter. This costs time during reassembly. Proper identification is a valuable asset when the new engine is reassembled in place. Lost and broken bolts, in some cases, do not exist as onboard spares. Therefore, you need to exercise care in disassembling and handling. Once bags have been filled and identified, place them in a secure place until they are required for the reassembly.

Replacement Engines Replacement engines, when received, may not be complete with all the fittings and adapters necessary for connection. In some cases, a replaced engine was in the container and heading for the supply depot before this discovery was made. This caused additional time to be wasted reopening the container and resealing it after the parts or items were removed. Time has also been lost when the replacement engine's turbine midframe flange was improperly clocked and another engine had to be brought to the changeout site.

Silencers Mark the location of the silencer hold-down brackets before removal. Proper marking makes it much easier to reinstall the brackets and silencers.

Quality Assurance Review QA requirements of Combined Forces Afloat Quality Assurance Manual, COMNAVSUR-FLANTINST 5090. lA and COMNAVSURFPACINST 4855.22, for level A repairs.

GTG ENGINE CHANGEOUT GTG engine changeout procedures are described in detail in the technical manuals, Model 104 Gas Turbine Generator Set, volume 2, and Model 139 Gas Turbine Generator Set, volume 2. These procedures provide detailed engine and interference removal instructions. These instructions should be strictly followed due to the vast differences in removal procedures between a propulsion GTE and an SSGTG.

You must use the same planning skills and engineering practices in a GTG engine changeout as you use in an LM2500 GTE changeout. The same strict application of safety precautions and following of technical manual procedures apply to every GTG engine changeout.

COOPERATION Ship's readiness is the common purpose in the changeout evolution. All personnel involved should share a common commitment in achieving that purpose. A willingness by each individual to submerge his or her personal interest in favor of getting the job done is a necessary prerequisite to cooperation. You may have to adjust working hours and watch-standing duties to meet changeout schedule requirements. Personnel may be assigned to duties they do not want to perform. Emphasize each individual's importance, willingness, and contribution to the evolution. Engine changeout is an opportunist y to display your professional abilities as a leader and technician

MAINTENANCE TIPS As a GS supervisor you will be responsible for the proper completion of most maintenance procedures. This section will cover some maintenance tips that can help you to understand the critical relationship between maintenance performance and the proper operation of the LM2500. Remember, the contents of this section are FOR TRAINING PURPOSES ONLY and should in no way replace the use of the PMS or the manufacturer's maintenance procedures.

PLA RIGGING If the PLA is replaced for whatever cause, the PLA rig check (mechanical and electrical) must be accomplished. If the main fuel control (MFC) rig pin does not fit properly (too loose, too tight, or can't be fully inserted), re-rig the PLA. Always comply with the PLA electrical rig check after you are assured that the throttle command voltages are properly set (idle and full throttle).

 







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