SN 29981 rotor repair SOW dtd 26Nov2019.docx

26 Nov 2019

NSN 2S 2010-01-534-8269 P2

Repair Statement of Work (SOW) SSN 774 Class Rotor

SN 29981

The following references apply:

(a) Technical Data Package & CDRL's A001, A004, A005, A006, A007, A008, A009

(b) NAVSEA S9245-AZ-TSM-010/PROP (C)

(c) NAVSEA 245-8328548 Rev B (C), Dimensional Inspection Requirements

(d) NAVSEA 245-7384173 Rev A (U), Propulsor Packaging and Preservation including Configuration Change Request No. 245

(e) NAVSEA 245-8328541 Rev D (U), VA Rotor Field Replaceable Hardware

(f) NAVSEA 245-7651134 Rev A (U), NDP3.1H Rotor Hub Drill Jig for AM Tailcone Holes

(g) NAVSEA 245-8328557 Rev B, SSN 774 Propulsor AM Tailcone

(h) NAVSEA 245-8357290 Rev A, VA Class Propulsor Threaded Inserts

(i) NAVSEA S9245-A4-TSM-010, Propulsor Paint Preservation

(j) NAVSEA 245-7642137 Rev E (C), Rotor Assembly NDP3.1HC

(k) NAVSEA 245-8216580 Rev A, Virginia Class Propulsor Axis Vertical Lifting Details and Transporter Attachment Procedure

(l) NAVSEA 245-7642140 Rev A, SSN774 Class Rotor Strongback Packaging Details

(m) NAVSEA 245-7642139 Rev A, SSN774 Rotor Strongback Trailer Loading

(n) MIL-DTL-2845, Propulsion Systems, Boat And Ship; Main Shafting, Propellers, Bearings, Gauges, Special Tools, and Associated Repair Parts; Preservation, Packaging, Packing and Storage of

The following notes and miscellaneous requirements apply.

1. All inspections and repairs shall be performed in accordance with references (a) through (n), as applicable, except as noted herein. In the event of a conflict between the references cited and this statement of work, the statement of work shall take precedence.

2. The facility must have personnel that have CONFIDENTIAL clearance and have successfully completed the NAVSEA Ducted Propulsor Visual Inspection Course.

3. CONFIDENTIAL inspection forms shall be submitted as a separate inspection report.

4. The vendor shall provide coatings qualification documentation. If the vendor is not qualified to perform blasting and painting operations, they have the option to identify a qualified subcontractor to perform blasting and painting operations. All personnel performing abrasive blasting shall have CONFIDENTIAL clearance and shall be certified in accordance with SSPC C-7, Abrasive Blasting. All personnel performing coatings application shall have CONFIDENTIAL clearance and shall be certified in accordance with Spray Application Certification or SSPC C-14, Marine Plural Component Program.

5. Stacking of VA class rotors is not authorized.

6. The rotor does not have side lifting points and a turnover fixture or J-bar is required for flipping. The means for flipping is the responsibility of the vendor and there is no GFE turning fixture designated for refurbishment work. The required sling length is a minimum of 15 feet for a straight lift, but a spreader bar is an acceptable alternative to maintain minimum 81 degree sling angle in accordance with Sheet 004-12 of reference (k).

ITEM 0002: Pre-Repair

1. Provide support to unload the rotor and strongback assembly from shipping trailer in accordance with references (l) and (m).

2. Remove paint layers, anti-fouling (AF) and anticorrosion (AC) from all painted surfaces by abrasive blasting or hand sanding. Blast media shall be in accordance with reference (i).

3. Conduct moisture removal procedure. The following requirements apply:

a. Rotor must be positioned pressure face down.

b. Heat must be applied to the entire blade. The temperature must be held in the temperature range of 140°F to 160°F. Heat can be applied through the use of a forced air heater and a custom heater bag designed to be slipped on over the blade to contain the heat.

c. Heat must be monitored by thermocouples mounted on the blades.

d. A vacuum must be applied to the entire blade during the heating process.

e. A sight glass shall be installed in-line with the vacuum pump to monitor presence of water.

f. A minimum pressure of 26” Hg should be held by the vacuum pump(s) throughout the entire evolution, approximately 10 days.

4. Perform a pre-repair liquid penetrant (PT) aided visual technical inspection (VTI) on all surfaces in accordance with reference (a) and (b).

5. Remove previously installed bushings using hydraulic jacks.

6. Perform pre-repair dimensional inspection of every blade and hub outer surface using laser scanning inspection process to generate a dense point cloud of inspection data. Probe measurement uncertainty (error) shall be taken into account in accordance with ISO Standard 14253-1 when evaluating surface best fits. Currently, only Laser tracker and LEICA T-Scan equipment are approved for data acquisition. The data acquisition software and point cloud density requirements are:

a. Three hundred (300) points/sq-in for the leading edge and cusp region (extending 3" from LE).

b. One hundred (100) points/sq-in for the tip and trailing edge region (extending 5" from tip and 3" from TE).

c. Twenty (20) points/sq-in for the blade faces, hub fillets, and the hub outer surface.

The pre-repair data shall be provided to Propulsor Technology, Inc. (PTI) at the address provided below for Navy repair evaluation (vendor is not responsible for the pre-repair evaluation of the collected data). The Navy evaluation will be provided to the vendor within 21 days of receipt of data. A copy of the Navy evaluation shall be included as part of the vendor’s dimensional report.

Propulsor Technology Inc.

80 Emerson Lane Suite 1302 Bridgeville, PA 15017-3472 Attn: Jim Machin, 412-914-1100

7. Perform System 21 Class 2 thread inspection on forward and aft hub face threaded holes used for lifting, handling and tailcone attachment. If the threaded holes fail the System 21 thread inspection, perform System 22 inspection.

8. Perform flange gage inspection in accordance with NAVSEA 245-8328556.

9. Perform LEICA scan of NAVSEA validation artifact. Scan data will be provided to PTI for information only.

INSPECTION AND ACCEPTANCE: Inspection and acceptance of Item 0002 shall be in accordance with reference (a).

ITEM 0004AA: Shipping Materials, Accessories, Balance Weights and Bushing Material

1. Procure one rotor set of the Item 3 bushings (12 each), hub flange sleeve, in accordance with reference (e). Procure additional material to accomplish certification testing and retain a permanent heat sample record. Remove previously installed bushings and replace with Item 3 procured above.

2. Procure one rotor set of AM tailcone attachment hole plugs, Item 8328541-11, QTY (21).

3. Replace the following FWD face accessories as required:

a. FWD hub packaging hole plug, Item 8328541-9, QTY (8)

b. FWD lifting hole plug, Item 8328541-7, QTY (4)

c. Hub flange pin hole plug, Item 8328541-5, QTY (3)

4. Procure replacement security covers in accordance with reference (d).

5. Procure machined balance correction weights in accordance with reference (j).

6. Procure wood blocking and friction matting for shipment as required.

ESTIMATED COST: Not separately priced.

ITEM 0004AB: Repair and Inspection of Propulsor Rotor

1. Repair surface and edge defects as identified during pre-repair inspection and approved by NSWCPD 426 by blending and welding as necessary. Hydro surface fairing rod inspection shall be accomplished on all repaired areas. Gages may be used as a guide.

2. Repair threaded holes as required based on results from pre-repair inspection. Threaded holes shall be repaired and inspected in accordance with reference (b). Tailcone attachment holes shall not be welded and shall be repaired in accordance with reference (h).

3. If required, drill and tap AM tailcone attachment holes in accordance with references (f) and (j). Drill fixture will be provided as GFP.

4. Restamp hub OD data as required in accordance with reference (j) and add the following, REP & BAL, (VENDOR) DATE (MM/YY).

5. Perform visual inspection of the rotor external surfaces prior to blast and paint application in accordance with references (a) and (b), as applicable. Additional PT inspections are not required once performed at individual repaired areas. Provide advanced copy of VTI to NSWCPD 426 for acceptance prior to blast and paint application.

6. Perform dimensional inspection of every blade and hub outer surface using laser scanning inspection process to generate a dense point cloud of inspection data. Probe measurement uncertainty (error) shall be taken into account in accordance with ISO Standard 14253-1 when evaluating surface best fits. Currently, only Laser tracker and LEICA T-Scan equipment are approved for data acquisition. The data acquisition software and point cloud density requirements are:

a. Three hundred (300) points/sq-in for the leading edge and cusp region (extending 3" from LE).

b. One hundred (100) points/sq-in for the tip and trailing edge region (extending 5" from tip and 3" from TE).

c. Twenty (20) points/sq-in for the blade faces, hub fillets, and the hub outer surface.

The data shall be provided to PTI for information in the event that Navy technical support is required. Provide an advance copy of the evaluation to NSWCPD Code 426 following post repair inspection. Need for additional fairing will be determined by NSWCPD Code 426 from the analysis of results.

7. Paint system(s) shall be applied in accordance with reference (i), Appendix C. A minimum of 4 dry film thickness (DFT) measurements shall be taken on each blade face. DFT measurements shall be taken at 3 locations on the hub outside diameter and 3 locations on the hub inside diameter. As required, Phillybond TA-30 shall be applied to seams and porosity after the first coat of paint has cured. The TA-30 shall be faired in to match surrounding surface and reapplied, if required, to ensure fairness. These repairs shall be roughened with 120 grit emery paper before application of the second coat of paint. All coatings inspections shall be performed by a Level 3 NACE Certified Coatings Inspector in accordance with reference (i). Upon completion, the NACE certified inspector shall provide written verification of successful coatings application to the vendor and NSWCPD Code 426.

8. Perform rotor balance following paint application. Note VA Class rotors do not have a tapered bore. Balancing operations require a vendor furnished balance adapter plate. The design of the adapter plate must be approved by NSWCPD Code 426. Note that the hub flange alignment pin hole plugs shall be installed during balancing operations. Remove the hub flange alignment pin hole plugs when balance is complete. A total of three balance runs shall be performed at the Top Dead Center (TDC) position as follows:

a. Perform one initial balance run.

b. Perform one balance run following balance weight installation.

c. Remove the rotor from balance machine. Re-install rotor on the balance machine and perform an additional balance run.

The first two balance runs shall be submitted as the initial and final data. The third balance run shall be provided for information only.

9. Provide support for acoustic tank testing per Advanced Engineering Consultants (AEC) Drawing ME-1, NAVSEA TEST TANK. Acoustic test tank is provided as GFP. Support includes but is not limited to the following:

a. Assembly of Navy test tank, liner, plumbing connections. The test tank is 24 feet in diameter and 7 feet tall. A CONFIDENTIAL space of 30 feet in diameter is recommended to accommodate equipment and tank access. The vendor shall provide a stairway to gain access to the tank.

b. Purchase and/or rental of water pump, filter, and heating and cooling equipment.

c. Fill tank (approx. 15,000-20,000 gallons).

d. Install AM tailcone hole plugs prior to the acoustic test process.

e. Provide miscellaneous (i.e. crane) support to Navy Acoustic Test Personnel during testing.

f. Drain and disassemble tank.

10. Paint balance weights and perform touch up painting.

11. Following complete paint application and balancing, perform final VTI of all hydrodynamic painted surfaces to ensure they conform to the coatings requirements.

12. The following actions apply to the rotor accessories:

a. The twenty one (21) AM tailcone attachment hole plugs shall be provided unpainted and not installed.

b. The eight (8) FWD hub packaging hole plugs shall be provided blasted and primed in accordance with reference (i). FWD hub packaging hole plugs shall not be installed.

c. The three (3) Hub flange pin hole plugs shall be provided with the heads blasted and primed in accordance with reference (i). Hub flange pin hole plugs shall be provided in a separate shipping container.

d. The four (4) FWD lifting hole plugs shall be provided with the heads blasted and primed in accordance with reference (i). FWD lifting hole plugs shall be installed.

e. Provide a shipping container for rotor accessories in accordance with reference (n). Shipping direction will be provided via separate correspondence.

13. Prepare the rotor for transit in accordance with references (d) and (l). Note that strippable coating shall not be applied. The AC/AF preservation paint must be cured prior to packaging in accordance with the applicable dry to touch and dry to handle times. The cured paint film shall resist a thumb deformation test (similar to ASTM D1640, paragraph 7.7.1) before packaging can begin.

14. Provide support to load the rotor and strongback assembly onto shipping trailer in accordance with references (l) and (m).

The following GFP shall be used for Item 0004AB:

1. PROPVAL Analysis program for SSN 774 Class Rotor

2. Navy Acoustic Test Tank

3. SSN 774 lifting padeyes

4. Rotor shipping strongback

5. Rotor Flange inspection gage

6. Rotor Hub Drill Jig for AM Tailcone Holes

ESTIMATED COST: $000.00

SHIPPING: The rotor shall be shipped to the following address:

DLA-Distribution Pearl Harbor/ZOM 667 Safeguard St Building 167-1/DMI Pearl Harbor HI 96860.

Attn: Harold Imai

INSPECTION AND ACCEPTANCE: Inspection and acceptance of Item 0004 shall be in accordance with reference (a) by 12 FEB 2021.

ITEM 0006: Data

Data for pre-repair (ITEM 0002) shall consist of the following items in accordance with reference (a) as applicable and as specified herein. (CDRL’s A004, A005, A006, A009 apply.)

1. PROPVAL LEICA Scan Report

2. Pre-repair VTI

3. Pre-repair UT inspection

4. Bushing dimensional inspection

5. Threaded hole dimensional inspection

6. LEICA scan data from the NAVSEA validation artifact (with one additional copy to PTI).

Data for post repair (ITEM 0004) shall consist of the following items in accordance with reference (a) as applicable and as specified herein. (CDRL’s A004, A006, A007, A008 apply.)

1. Drying procedure certificate of compliance (CFC)

2. Post repair PROPVAL LEICA Scan Report, if required

3. Post repair UT inspection if required

4. Pre-Blast VTI

5. Post Paint VTI - Rotor final condition and condition of accessories (painted and/or installed)

6. Coatings application CFC

7. Accessory cert package

8. Balance inspection forms

9. New bushing report with material certs and dimensions

10. AM Tailcone hole dimensional inspection

NAVSEA inspection form 9245/9 shall be utilized in lieu of NAVSEA form 9245/3. Submit inspection reports to NSWCPD 426 and copy of the report transmittal letter to NAVSUP WSS N97121. Allow 15 days for government review and approval.