0967_A_SHAFT ALIGNMENT AND BEARING REACTION CHECKS 3 AND 4_TAOE_CSI.docx

USNS XXXXXX

(T-AOE X)

SHAFT ALIGNMENT AND BEARING REACTION CHECKS 3 AND 4 (5 YR)

ABSTRACT

The purpose of this item is to measure and analyze the propulsion system alignment and bearing reactions.

REFERENCES/ENCLOSURES

References NAVSEA Drawing No. 243-6360792, Propulsion Shafting Arrangement NAVSEA Drawing No. 243-6360795, BHD Shaft Seal Assembly NAVSEA Drawing No. 243-6360797, Stern Tube Seal Assembly and Details NAVSEA Drawing No. 161-6361935, Struts, Stern Tube Bearings and Stem Castings NAVSEA Drawing No. 244-6360796, Main Propulsion Shafting Water Lubricated Bearings NAVSEA Drawing No. 243-6360794, Intermediate and Stern Tube Shaft Details Port and Starboard NAVSEA Drawing No. 161-6360800, Propulsion Shafting Fairwaters and Rope Guard NAVSEA Drawing No. 243-6360793, Propeller Shaft Details MSC Drawing No. 243-8390431, Main Propulsion Alignment Procedure NAVSEA Tech Manual S9086-HM-STM-010, NSTM Chapter 243 Propulsion Shafting NAVSEA Tech Manual S6420-AC-HBK-010, Handbook, Bearings, Measurement of Load NAVSEA Tech Manual S9086-HN-STM-010, NSTM Chapter 244, Propulsion Bearings and Seals ABS Guidance Notes on Propulsion Shafting Alignment Enclosure Shaft Alignment Summary Forms

ITEM LOCATION/DESCRIPTION

Locations Stern of ship Machinery Room 1 (MMR 1)(7-455-01-E) Main Machinery Room 2 (MMR 2)(7-510-01-E) Shaft Alley (7-565-1-Q) Quantity: See References 2.1.1 through 2.1.8 Item Description/Manufacturer’s Data: See References 2.1.1 through 2.1.8

GOVERNMENT FURNISHED EQUIPMENT/MATERIAL/SERVICE

Government Furnished Equipment: None Government Furnished Material: Lube Oil Government Furnished Service: None

NOTES

The contractor and all subcontractors, regardless of tier must consult the General Technical Requirements (GTR) to determine applicability to this work item. In performance of this work item, the contractor and all subcontractors regardless of tier must comply with the requirements of all applicable GTR’s including but not limited to GTR’s 1 through 7, 22, 23, 24, 28, and 29.

The contractor and all subcontractors regardless of tier are advised to review other work items under this contract, including but not limited to Work Items 023, 901 and XXX to determine their effect on the work required under this work item. Many of the definitions relating to performance of this work item are found in Work Item 001.

The need for these two additional sets of shafting system alignment checks will be determined with the help of MSC N72, Phone: (757)341-5983, Email address: MSC_NRFK_N72@navy.mil. Potential situations that would require these additional checks are:

1.1.1 Misalignment is suspected; e.g., repeated system bearing failures, reduction gear elements showing abnormal tooth contacts, and unexplained shafting system vibration.

1.1.2 Ship damage has occurred; e.g., grounding, collision (strain gauge method cannot determine shaft journal runout)

1.1.3 Conducting a drydock availability (or other availability) where work will be performed that may affect shaft alignment, e.g.,

a. Significant welding or other structural work in the general vicinity of the propulsion plant, reduction gear or propulsion shafting.

b. When propulsion shafting is removed,

c. When propulsion shaft linings or bearings are replaced

2.0 QUALITY ASSURANCE REQUIREMENTS: None additional

3.0 STATEMENT OF WORK REQUIRED

3.1 Measure the propulsion system alignment using References 2.1.1 through 2.1.13 as guidance.

3.2 Provide the services of an MSC approved Engineering firm to accomplish the shaft alignment measurement and analysis of this work item. All work shall only be accomplished by trained, experienced and authorized service personnel.

3.3 SAFETY PRECAUTIONS: At a minimum, adhere to the following safety practices during testing:

3.3.1 Coordinate with ship’s force to have associated equipment locked and/or tagged out per ship’s lock out/tag out policy. When the maintenance is complete, coordinate with ship’s force to have associated equipment unlocked and/or tagged in per ship’s lock out/tag out policy.

3.3.2 Prior to rotating any shafting an inspection is to be made ensuring all equipment is ready and free to rotate including the propeller, protective guards are in place and the area is clear of all unnecessary material and personnel. All shaft movements are to be coordinated with senior Shipyard personnel, the vessels Chief Engineer and OMT REP prior. Ensure shaft brake is disengaged prior rotating any shafting and equipment.

3.3.3 Apply a heavy coat of clean lube oil across the journals, thrust faces and bearings to provide initial lubrication prior to turning the shaft.

3.3.4 When turning the shaft with turning gear be constantly alert to any indication of bearing stress such as noises in the reduction gear or overloading of the turning gear motor. Stop the turning at the first indication.

3.3.5 Bearing inspection covers must be kept closed and locked except when it is absolutely necessary that they be open for inspection or service. When bearing casings are open, precautions should be taken to prevent the entry of foreign matter. The openings are never to be left unattended. Before replacing an inspection plate, connection, fitting, or cover which permits access to the casing, a careful inspection is to be made to ensure that no foreign matter has entered or remains in the casing or oil piping.

3.4 Verify all shaft bearings are chocked, bolted and torqued prior to performing this test.

3.5 No structural work in the vicinity of shafting system, propeller repairs, changes in tank conditions or movements of weights may be made during the alignment process. Shafting alignment is to take place in the late evening or early morning to minimize effects of hull deflection.

3.6 Install temporary markings of 0°, 90°, 180° and 270° on the periphery of the reduction gear flange or on the shaft in a position clearly visible to the turning gear operator.

3.7 Conduct propulsion shafting alignment testing and analysis using References 2.1.1 through 2.1.13 as guidance to document and confirm bearing loads and system alignment. The examination is to measure and record the static load on each inboard shaft support bearing, including both bull gear bearings and forward stern tube bearing if accessible. The Strain Gage Method is to be used for measuring shaft loads (Set No. 1 through 5). These measured bearing loads are to be validated by comparison to readings taken using the Jack-Up Method (lift and load) on at least one bearing per shaft (Set No. 1 and 3).

3.8 The testing is to consist of two (2) sets of readings:

3.8.1 A minimum of five (5) gage stations on port shaft and three (3) gage stations on stbd shaft are to be installed on each propulsion shaft. All gage stations are to be either half or full bridge configuration, quarter bridge stations are not authorized.

3.8.2 Set No. 1 and 2: Waterborne and On Dock – These initial two sets of readings will be conducted and priced separately under Work Item 966 for every ROH.

3.8.3 Set No. 3: On Drydock - after the re-installation of all shafting components and reestablishment of the “dry dock” internal load condition recorded in Set No. 2 and prior to water entering the dry dock. If the vessel is dry docked on a floating dock the dock trim and load condition must be similar to that at the time of the second set of measurements including positions of wing-wall mounted cranes. Record strain gage readings, jack-up readings and bearing clearances.

3.8.4 Set No. 4: Waterborne - after the vessel is afloat and reestablishment of the “original waterborne” internal load condition as recorded in Set No. 1. The final alignment of the main propulsion shafting of a vessel should always be accomplished when the vessel is waterborne. Per ref 2.1.10, when coming out of drydock, the ship’s hull should be given time to stabilize in the water (up to two days) prior to performing the final alignment checks. Record strain gage readings.

3.9 Record the vessel conditions and ambient environmental data at the time of each set of alignment measurements. The following data at a minimum shall be recorded:

3.9.1 Vessel drafts; forward, midship (port and starboard) and aft.

3.9.2 Water depth at stern, ensure vessel is not resting on the bottom.

3.9.3 Load condition of all tanks (tons) via tank soundings.

3.9.4 Computer printout (Cargomax) – to be provided by the ship’s Master.

3.9.5 Ambient temperature and weather conditions

3.9.6 Sea water temperature (afloat measurements only)

3.9.7 Reduction gear oil sump and low speed gear bearing temperatures

3.9.8 All propulsion shaft radial and thrust bearings

3.9.9 Lower engine room and shaft alley temperatures

NOTE: Enclosure 2.2.1 is not specific to USNS ARCTIC (T-AOE 8). A ship specific enclosure needs to be developed, completed, and submitted.

3.10 Provide a condition report of all raw measured data, using Enclosure 2.2.1 as guidance, after each set of readings within one (1) day of completion of each set of alignment measurements to the OMT REP.

3.11 Upon completion of all alignment checks the measured data is to be evaluated by the Engineering firm and a complete assessment made as to the acceptability of the alignment. The analysis, assessment and any recommended bearing adjustments are to be submitted to the OMT REP and ABS Surveyor within two (2) days of completion of each set of alignment measurements to include completed Enclosure 2.2.1. The assessment is to account for, as applicable, the various factors affecting alignment (thermal growth, waterborne bearing wear, and ship loading) as well as the limiting design parameters of the shafting system (maximum and minimum bearing loads, allowable bull gear bearing load differential, and maximum allowable waterborne bearing wear).

NOTE: The alignment data, assessment and any recommendations are required to be reviewed and approved by MSC N72 prior to authorizing any shaft alignment changes. Phone: (757)341-5983, Email address: MSC_NRFK_N72@navy.mil.

3.12 All propulsion shaft alignment measurements are to be coordinated with the ABS Surveyor, OMT REP and Chief Engineer to allow for observation.

3.13 Coordinate with ship’s force to tag-in all required systems and equipment.

3.14 Reports

3.14.1 When inspection, service and testing reveal any deficiency a condition report is to be submitted to the OMT REP with recommended repairs and parts required. Submit one (1) electronic copy in Portable Document Format (PDF).

3.14.2 Submit a report that includes “as released” condition of the propulsion shafting system. Submit one (1) electronic copy in Portable Document Format (PDF).

3.14.3 All reports and checklists are to be completed and signed by the person who carried out the inspection and maintenance work and countersigned by the Company’s representative.

3.15 Painting: None additional

3.16 Manufacturer’s Representative

3.16.1 Provide the services of an Engineering firm and onsite Technical Representative experienced in marine propulsion shaft alignment and in particular the strain gauge method on ABS classed vessels. They are to collect and analyze bearing loading data, determine the vessels shaft alignment and propose any needed changes. The Rep is to be present onboard the vessel during the data collection, alignment process as well as Sea Trials. A resume describing the qualifications and experience of both the company and technical rep is to be provided to the OMT REP for review and approval prior to the start of the shaft alignment process. Suggested Sources:

3.16.2 Diehl Engineering

PO Box 1573 Kingston, WA 98346 POC: Eric Diehl Telephone: (360) 297-8781 Mobile: (360) 981-4340 ediehl@diehlengineering.com info@diehlengineering.com www.diehlengineering.com/contact/

3.16.3 Maritech, LLC

Powder Mill Rd, PMB 341 Acton, MA 01720 POC: Larry Duddy Telephone: (508)-759-6308 Mobile: (978) 897-9379 larry@maritech-llc.com/info@maritech-llc.com www.maritech-llc.com

3.17 Preparation of Drawings: None additional

4.0 GENERAL REQUIREMENTS: None additional

ENCLOSURE 2.2.1 - SHAFT ALIGNMENT SUMMARY FORMS

SHAFT ALIGNMENT SUMMARY

Vessel Name

Shipyard

Hull No.

Date

Time

ENCLOSURE 2.2.1 - SHAFT ALIGNMENT SUMMARY FORMS

Pictographic View (displaying location of shafts, couplings, bearings and strain gauge stations) Samples below

ENCLOSURE 2.2.1 - SHAFT ALIGNMENT SUMMARY FORMS

Strain Gauge Station

Strain Gauge Method

Position

Strain Gauge Station No.

0°

90°

180°

270°

0°

Vertical Strain

Stress (lb/sq.in.)

Bending Moment (lb-in)

Horizontal Strain

Stress (lb/sq.in)

Bending Moment (lb-in)

Station Gauge Factor

Measurement Gauge Factor

Station Bridge Configuration

ENCLOSURE 2.2.1 - SHAFT ALIGNMENT SUMMARY FORMS

Strain Gauge Method

Bearing Loads

Stern Tube Bearing

Strut Bearing

Aft Lineshaft Bearing

Fwd Lineshaft Bearing

Aft MRG Bearing

Fwd MRG Bearing

Thrust Bearing

Bearing Loads

(in)

Aft Lineshaft Bearing

USNS ARCTIC

(T-AOE 8)

SHAFT ALIGNMENT AND BEARING REACTION CHECKS 3 AND 4 (5 YR)

+down 967-6

ENCLOSURE 2.2.1 - SHAFT ALIGNMENT SUMMARY FORMS

Jack-UP Method

Bearing Reaction Influence Number = (lbs per 0.001 inch rise in Bearing)

Bearing Aft Lineshaft Bearing

MRG Bearing Fwd MRG Bearing

Stern Tube Bearing

Strut Bearing

Aft Lineshaft Bearing

Fwd Lineshaft Bearing

Thrust Bearing

Aft MRG Bearing

Fwd MRG Bearing

ENCLOSURE 2.2.1 - SHAFT ALIGNMENT SUMMARY FORMS

Bearing Reactions (pounds)

Bearing Aft Lineshaft Bearing

MRG Bearing Fwd

Set No.1

Set No.2

Set No.3

Set No.4

Set No.5

ENCLOSURE 2.2.1 - SHAFT ALIGNMENT SUMMARY FORMS

Bearing Reactions (psi)

Bearing Aft Lineshaft Bearing

MRG Bearing Fwd

Set No.1

Set No.2

Set No.3

Set No.4

Set No.5

Allowable Pressure (psi)

Bearing Length (in)

Journal Diameter (in)

Projected Brg Area (sq.in)

Lubrication (oil/water)

USNS XXXXXX

(T-AOE X)

SHAFT ALIGNMENT AND BEARING REACTION CHECKS 3 AND 4 (5 YR)

ENCLOSURE 2.2.1 - SHAFT ALIGNMENT SUMMARY FORMS

Alignment Recommendations

(psi) Bearing Reaction (lb) Pressure (psi) Delta (lbs)

Stern Tube Bearing

Strut Bearing

Aft Lineshaft Bearing

Fwd Lineshaft Bearing

Thrust Bearing

Aft MRG Bearing

Fwd MRG Bearing

Prescribed Moves:

Engineering Approval:

Date:

Calibrated Measuring Instruments

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