Sxx_xxxx_23300_MWC_Nmbr2MnDslEngnRprs_0918_65401.doc

Sxx_xxxx_23300_MWC_0918_65401 WORK ITEM 1: #2 Main Diesel Engine (MDE), Repairs

1. SCOPE

1.1 Intent. This work item describes the requirements for the Contractor to conduct the following repairs on the #2 Main Diesel Engine (MDE) while the vessel is afloat.

· Renew the crankshaft rear oil seal

· Renew cylinder head gaskets and associated software (water and oil seal rings, compression gaskets, seal ring, etc) on both banks

· Conduct operational flush of the engine lube oil system

NOTE

#2 MDE currently installed is a GM Detroit Diesel Model 8V71 (S/N: 8FV2367, M/N: 7082-3000), utilizing an Allison MH-30L reduction gear (S/N: 9684).

1.2 Government-furnished property.

None.

2. REFERENCES

Coast Guard Drawings

Coast Guard Drawing 65-BUS 103-006, Rev D, Booklet of Plans (ELDERBERRY)(65401) Coast Guard Drawing 65-BUS 4000-002 Rev -, Machinery Arrangement

Coast Guard Drawing 65-BUS 4301-003 Rev A, Stern Tube, Shafting, and Bearing Arrangements and Details (ELDERBERRY)

Coast Guard Publications

Surface Forces Logistics Center Standard Specification 0000 (SFLC Std Spec 0000), 2014, General Requirements

Surface Forces Logistics Center Standard Specification 0740 (SFLC Std Spec 0740), 2014, Welding and Allied Processes

Other References

GM Detroit Diesel Engines V-71 Service Manual

3. REQUIREMENTS

3.1 General.

3.1.1 CIR.

None.

3.1.2 Tech Rep. The Contractor shall provide the services of a Qualified Technical Representative who is familiar with the GM Detroit Diesel Model 8V71 to accomplish the following on site:

· Advise on manufacturer's proprietary system information.

· Assist with installation.

· Ensure compliance with manufacturer's procedures and standards during system disassembly, inspection, and reassembly as applicable.

3.1.2.1 Ensure the Tech Rep has experience with the system/equipment stated above and demonstrated on their résumé.

3.1.2.2 Submit the name and résumé of the Tech Rep to the COR at the Arrival Conference.

3.1.3 Protective measures. The Contractor shall furnish and install all protective coverings to seal off and protect all non-affected vessel's components, equipment, and spaces near the work area against contamination during the performance of work. Upon completion of work, the Contractor shall remove all installed protective measures, inspect for the presence of contamination, and return all contaminated equipment, components, and spaces to original condition of cleanliness.

3.1.4 Interferences. The Contractor shall handle all interferences in accordance with SFLC Std Spec 0000, paragraph 3.3.5 (Interferences). Known interferences include, but are not limited to the following:

· Piping.

· Deck plates.

· Reduction gear.

· Propulsion shaft.

· Stuffing box and packing.

3.1.5 Operational test, initial. Prior to commencement of work, the Contractor shall witness Coast Guard personnel perform an initial operational test of all items or shipboard devices to be disturbed, used, repaired, or altered, to demonstrate existing operational condition. Submit a CFR.

3.2 Work to be accomplished. The Contractor shall accomplish the following for the #2 MDE, referring to the references listed in Section 2 “References” for additional information.

3.2.1 Rear seal renewal.

3.2.1.1 Disconnect the shaft coupling from the reduction gear output flange. Mark the existing shaft position, match-mark the shaft coupling bolts to their respective holes, and retain all hardware to facilitate reconnection.

3.2.1.2 Record existing alignment (face and bore) between the shaft and reduction gear; submit a CFR.

· Angular (face-to-face) readings in 4 positions at 90° intervals;

· Parallel (coupling OD-to-coupling OD) readings in 12 positions at 30° intervals.

3.2.1.3 Move the shaft aft to the extent necessary to support reduction gear removal.

3.2.1.3.1 Coordinate in conjunction with any required shaft axial movements, the loosening of the shaft packing gland to facilitate axial shaft movements. Once temporary movement have been made and engine work is occurring the packing should be tightened to control any interim leakage.

CAUTION

There exists approximately 8” of clearance between the propeller and rudder.

3.2.1.4 Disconnect all attached reduction gear piping and hoses. Drain and dispose of all reduction gear fluids in accordance with all applicable federal, state, and local regulations.

3.2.1.5 Disconnect the reduction gear from the MDE, retaining all hardware for reinstallation. Record the existing alignment between the reduction gear and MDE. Submit a CFR.

3.2.1.6 Move the reduction gear to the extent necessary to gain access to the engine flywheel housing. Remove the flywheel and ring gear to expose the crankshaft rear oil seal.

3.2.1.7 Inspect the rear end of the crankshaft for signs of wear. Submit a CFR.

3.2.1.8 Renew the engine’s rear oil seal using contractor-furnished parts in accordance with manufacturer’s instructions.

3.2.1.9 Upon completion of seal replacement, reinstall the ring gear and flywheel. Reconnect the reduction gear to the MDE using existing hardware. Reconnect all removed piping and hoses, ensuring all blanks and caps have been removed.

3.2.1.10 Reconnect the shaft coupling to the reduction gear output flange and check alignment as follows:

3.2.1.10.1 Again coordinate in conjunction with any required shaft axial movements, loosening the shaft packing gland to facilitate shaft movements. When shaft flanges have been bolted together adjust packing for normal operation. Do not overtighten. Final packing adjustment/observation can only be made with shafting turning (sea trials).

NOTE

The below tolerances are generally used for ideal conditions for shaft alignment. Compare these readings with those obtained prior to work (Para 3.2.2) to determine final acceptance.

3.2.1.10.2 Angular or Face Alignment. Bring the coupling flanges forward to within 0.5" face gap at all points about the diameter of the flanges. Take measurements of face gap at four equally spaced positions on the flange diameters using feeler gauge. Compare diametrically opposite face gap readings top to bottom, and inboard to outboard. Subtract the smaller of diametrically opposite readings from the larger. The resulting difference is proportional to the amount of angular or face misalignment. These readings shall not exceed 0.0005 inches per inch of companion flange outside diameter (0.004” for an 8” flange).

3.2.1.10.3 Parallel or bore alignment. Position the coupling flanges within 0.5" of each other and place a straight edge at 12 positions at 30° intervals. The bore or parallel misalignment shall not be greater than 0.005 inches.

3.2.2 Cylinder head gasket and software renewals.

3.2.2.1 Drain and dispose of engine coolant in accordance with all applicable federal, state, and local regulations.

3.2.2.2 Disconnect the exhaust piping, fuel lines, jacket water hoses, and associated components.

3.2.2.3 Remove the exhaust manifold and valve covers.

3.2.2.4 Remove the cylinder heads. Discard the cylinder head compression gaskets, oil seals, and water seals.

3.2.2.5 Drain and dispose of engine lube oil in accordance with all applicable federal, state, and local regulations.

3.2.2.6 Inspect the removed cylinder heads for signs of cracks. Perform a NDE of the removed cylinder heads in accordance with SFLC Std Spec 0740, Appendix C. Submit a CFR.

3.2.2.7 Renew the cylinder head gaskets and associated software using contractor-furnished parts.

3.2.2.8 Reinstall the removed cylinder heads and all removed components.

3.2.3 Operational lube oil flush.

3.2.3.1 Refill the engine fluid systems with the manufacturer’s recommended fluids.

3.2.3.2 Install high filtration oil filters (Detroit Diesel Filter p/n: 23530408 or equivalent) in support of operational flush.

3.2.3.3 Operate the engine, monitoring oil pressure and temperatures, under the direction of the Tech Rep.

3.2.3.4 After approximately two hours of run time, secure the engine. Remove the oil filters, cut open, and examine for debris and particles. Replace oil filters and repeat this process until satisfactory inspection results are achieved.

NOTE

The above periodicity is a recommendation and can be tailored based upon results achieved and Tech Rep recommendations.

3.2.3.5 Upon satisfactory oil filter inspections, submit a lube oil sample for water and metal wear analysis. Samples shall be obtained at the following checkpoints. Submit a CFR.

· After completion of operational flushing

· After completion of pierside testing.

· After sea trials.

3.3 Operational test, post repairs. After completion of work and in the presence of the Coast Guard Inspector, the Contractor shall thoroughly test and demonstrate the shafting, reduction gear, and MDE to be in satisfactory operating condition (pier-side and underway). Submit a CFR.

4. NOTES

This section is not applicable to this work item.