SR00055697 HARVEY MILK GENERATOR BEARING INSPECTION SERVICE REPORT.pdf

V01.052022

SERVICE REPORT

MSHS.COM • SERVICE@MSHS.COM • 800.622.6747 • SALES@MSHS.COM • PARTS@MSHS.COM

Form No 103-2H

MSHS

Name USNS HARVEY MILK TAO 206 GENERATORS BEARING INSPECTION Department SERVICE Job started 08.23.23 Job ended 08.28.23 Service Engineer ANGEL S PEREZ Job No. SR 00055697

CUSTOMER

Owner MSC Vessel/Plant USNS HARVEY MILK TAO 206 Location NASSCO SHIPYARD, SAN DIEGO, CALIFORNIA Purchase Order Number

EQUIPMENT

Engine Manufacturer Bergen Diesel ROLLS-ROYCE Engine Type B32:40 L8A Engine No. SSDG-1 (16497) SSDG-2 (16498) Running Hours SSDG-1 (466) / SSDG-2 (432) Nominal Output 3724 KW Speed 900 GENERATOR Manufacturer AVK GENRATOR Type DIG 156 p/10W GENERATOR No. G-1 (83 34780 A003) / G-2 (83 34780 A004)

OPERATING CONDITIONS

Fuel type MDO Viscosity

JOB/WORKORDER

GENERATORS PEDESTAL BEARING INSPECTION.

PARTICIPANTS

ANGEL S PEREZ

ALEX SHALIMO

RIGGING SUPPORT TEAM

SUPERINTENDENT ENG. (MSHS)

SERVICE ENG. (MSHS)

NASSCO SHIPYARD

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1. Summary

• Auxiliary Diesel Generators (SSDG-1 and SSDG-2), pedestal bearings inspection and reconditioning.

2. Work content

1- SSDG-1 Pedestal bearings inspection at both drive end and free end side.

1.1 Opening for inspection pedestal bearing at free end side. Inspect bearings shells and seals, clean all related parts and sump space, install parts back, tight all bolts as per OEM specifications.

1.2 Opening for inspection pedestal bearing at drive end side. Inspect bearings shells and seals, clean all related parts and sump space, install parts back, tight all bolts as per OEM specifications.

2- SSDG-1 Pedestal bearings inspection at both drive end and free end side.

2.1 Opening for inspection pedestal bearing at free end side. Inspect bearings shells and seals, clean all related parts and sump space, install parts back, tight all bolts as per OEM specifications.

2.2 Opening for inspection pedestal bearing at drive end side. Inspect bearings shells and seals, clean all related parts and sump space, install parts back, tight all bolts as per OEM specifications.

3. Parts installed n/a

4. Findings and Evaluations

1. Both pedestal bearings in SSDG-1 were opened for inspection and reconditioning. Found with normal load wear marks in the bottom bearing shells with some scores due to dirt particles from lubricating oil inclusion during prior assembly at factory.

The bearing at free end was previously inspected and opened by the vessel staff, so no evaluation of the tightness condition of the cover bolts could be accessed.

1.1 Free end side pedestal bearing shaft and bearing shells were found with a score produced by lubricating oil dirt particles inclusion, therefore the shaft was polished with 240 grit emeril cloth to provide the shaft with the right roughness and to improve the lubrication conditions.

The bearing shells were also cleaned and reconditioned to remove any high spot or damaged area induced by the particle inclusions. The bottom bearing shell was found with some electro pitting abrasion damages that couldn’t be totally removed (see related pictures for full details), this type of damage is induced due to shaft grounding failure (contact surfaces not clean or bad contact between grounding devise and shaft).

Both bearings shells from free end were found with a manufacturing texture defect (orange peel, see related picture for full details), this type of defect are cosmetic and do not imply a damage or weakness mailto:SERVICE@MSHS.COM of the bearing soft metal, therefore not implying a performance risk or a provable future damage as result of this condition.

1.2 Drive end side, pedestal bearing’s shaft and bearing shells were found with minor scores produced by lubricating oil dirt particles inclusion, therefore the shaft was polished with 240 grit emeril cloth to provide the shaft with the right roughness and to improve the lubrication conditions.

The bearing shells were also cleaned and reconditioned to remove any high spot or damaged area induced by the particle inclusions.

The bottom bearing shell was found with some electro pitting abrasion damages that couldn’t be totally removed (see related pictures for full details), this type of damage is induced due to shaft grounding failure (contact surfaces not clean or bad contact between grounding devise and shaft).

Both bearings shells from drive end were found with normal load marks and wear pattern, both cleaned and reinstalled back, assembled with clean oil and all bolts tight in compliance with the OEM torque specifications.

Both seals were found in good standing conditions, therefore not removed or replaced, installed back with not hardening silicone sealing compound.

All sealing surfaces were installed with the aid of Loctite 515 gasket replacement compound.

The shaft grounding device was thereafter installed by crew staff as well as the temperature sensors.

2. Both pedestal bearings in SSDG-2 were opened for inspection and reconditioning. Found with normal load wear marks in the bottom bearing shells, with some scores due to dirt particles from lubricating oil inclusion during prior assembly at factory. Free end bearing housing was found to be assembled with the aid of blue RTV silicone and grease on the bearings, also housing bolts were found to be heavily rusted and dirty, lubricating oil with showing grease contamination from assembling as well as dark coloration and dirt inclusion. Sealing surface in engine frame was found rusted as well (see related pictures for full details).

2.1 Free end side pedestal bearing shaft and bearing shells were found with minor scores produced by lubricating oil dirt particles inclusion, therefore the shaft was polished with 240 grit emeril cloth to provide the shaft with the right roughness and to improve the lubrication conditions.

The bearing shells were also cleaned and reconditioned to remove any high spot or damaged area induced by the particle inclusions. The bottom bearing shell was found with some electro pitting abrasion damages that couldn’t be totally removed (see related pictures for full details), see remarks from unit one in relation to this type of damage.

Both bearings shells from free end were found with an electric insulating coat in bearing shell support and cover (a black polymer layer that avoid metal to metal contact that differs from all other three bearing inspected in SSDG-1 and SSDG-2).

Drive end side, pedestal bearing’s shaft and bearing shells were found with minor scores produced by lubricating oil dirt particles inclusion, therefore the shaft was polished with 240 grit emeril cloth to provide the shaft with the right roughness and to improve the lubrication conditions.

Drive end bearing housing bolts were found lose, we were able to lose them just with the aid of a ¾ ratchet wrench, therefore just about 200 Nm or less. Take in consideration that the vertical bolts should be tight to 1160 Nm while the horizontal bolts located at the flange attached to the generator housing should be tight to 1450 Nm. Bottom flange bolts were found under tight in all bearing housings.

The bearing shells were also cleaned and reconditioned to remove any high spot or damaged area induced by the particle inclusions and or electro pitting abrasion.

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Free end bearing seal brackets were found installed 180o off set, meaning the top one installed at bottom position and vice versa, therefore removed cleaned and installed back in the right place with the seal in the right position. Both seals were found in good standing conditions, therefore not removed or replaced, sealing brackets were installed back with Loctite 515 gasket replacement compound and the seals with not hardening silicone sealing compound.

Both bearings shells from drive end were found with normal load marks and wear pattern, both cleaned and reinstalled back, assembled with clean oil and all bolts tight in compliance with the OEM torque specifications with aid of Loctite thread locker medium strength.

All sealing surfaces were installed with the aid of Loctite 515 gasket replacement compound.

The shaft grounding device was thereafter installed by crew staff as well as the temperature sensors.

Both SSDG’s thrust bearing clearance at free end bearings were measured with aid of filler gauge found at 0.5 mm. Both sides thrust bearings were found in good standing conditions without significant marks or scores, all cleaned and installed back (thrust bearings are part of the bearing shells). Radial clearances were measured with aid of filler gauge at the side of the bottom shells (as at top position will require a further dismantling of the top shell what we avoid), bearing clearances at side of the bearing shells were found at 0.15 mm.

5. Works/Checks not carried out

• Crank web deflection at SSDG engine crankshaft.

6. Recommendations

• Since all bearing housing bolts were found under tight, we do recommend inspecting the torque condition at all main diesel generators most important unions meaning, foundation, main bearings, big end bearings and cylinder heads before continuing with the running of the SSDG to ensure compliance with OEM specifications.

• Inspect SSDGs crank web deflection prior to test run the generator bearings.

• Test run bearings at 5’ and thereafter 30’ with infrared scanner monitoring during running to ensure no overheating or any damage to bearing shells.

• Prior running service bearing shell housing with about one gallon of clean oil, there after draining it to flush the housing from any particle that may be included during assembling process, there after filling up the housings with required amount of oil prior test run of the generators. After test run purge a small amount of oil from the sump to inspect from any metal or particles inclusion that may imply a bearing damage.

7. Returns of parts, tools, samples n/a

8. Related documents & Pictures

GROUNDING DEVICE ORANGE P. DEFECT

GENERATOR -2 FREE END BEARING BOTTOM SHELL

BLACK POLLYMER COATING GREASE USED IN ASSEMBLING FOUND IN SSDG -

2 FW SIDE BEARING

Felix Popescu

ANGEL S PEREZ

(Service Manager) (Superintendent Service Engineer) Service Department Service Department mailto:SERVICE@MSHS.COM