Group 12 and 13_PBPL_WPB-87_LH _ RH_NSN 2010-01-459-0421 and 2010-01-457-0573.pdf

24599_87_MWS_1225_Rev -

Work Item 1: Propeller, 87 WPB - Inspect, Repair/Overhaul

1. SCOPE

1.1 Intent – This work item defines the requirements for repair and overhaul of US Coast Guard 87’

Patrol Boats.

1.2 Government furnished property (GFP). The listed items are property of and managed by the United

States Coast Guard (USCG) Surface Forces Logistics Center (SFLC), Baltimore MD and will be issued to the contractor as issuance of a contract or contract delivery order.

ITEM DESCRIPTION NSN

P/N

CAGE

Propeller, Right Hand NSN: 2010-01-457-0573

P/N: 706-3351.00 RH

CAGE: 81340

Propeller, Left Hand NSN: 2010-01-459-0421

P/N: 706-3350.00 LH

CAGE: 81340

Shipping Crate, Reusable NSN: N/A

PN: N/A

CAGE: N/A

2. REFERENCES

COAST GUARD DRAWINGS/RENDERINGS

Coast Guard Drawing 87 WPB 245-003, Rev. A – 87’ Coastal Patrol Boat

Propeller Details

COAST GUARD PUBLICATIONS

87 Propeller Inspection Compliance Forms

OTHER REFERENCES

ABS Rules for Survey After Construction 2021 - Guide for Bronze and Stainless-Steel Propeller

Castings, Part 7 Appendix 1, Section 10

ASTM E1417/E1417M, Dated 9/1/2021 – Standard Practice for Liquid Penetrant Testing

ISO 484-2:2015(E) Second Edition, Dated 12/01/2015 – Shipbuilding-Ship Screw Propellers-

Manufacturing Tolerances - Part 2: Propellers of Diameter Between 0.80 and 2.50 m

Inclusive

3. REQUIREMENTS

3.1 General.

3.1.1 Inspection, repair and overhaul - general. All inspections, repairs and overhaul must be accomplished in accordance with the requirements set within this work item. Coast Guard Drawing 87

WPB 245-003 must be used for the baseline design criteria and ISO 484/2, Class 1 (unless otherwise noted) for the inspection processes.

3.1.2 Workmanship. Upon completion of all work, all propellers must have a polished, professional finish and be free of dirt, grease, burrs, sharp edges, etc.

3.2 Inspections. The Contractor must accomplish the following inspections for each 87 propeller received:

3.2.1 Arrival inspection.

3.2.2 Visual Preservation Inspection (VPI).

3.2.3 Visual and Technical Inspections (VTI).

3.2.4 Geometrical/dimensional inspections. Prior to overhaul/repair, the Contractor must conduct the following inspections and measurements, recording all results in the 87 Propeller Compliance Forms.

NOTES

ISO 484/2 is the guiding document for the inspections to be made. Class 1 measurements and tolerances apply unless explicitly stated otherwise.

The Compliance Forms tolerance bands are derived from Coast Guard

Drawing 87 WPB 245-003 with ISO 484/2, Class 1 tolerances applied (unless otherwise noted).

The pitch data derivations for the Compliance Forms incorporate a 0.5 inch exclusion each from the trailing edge AND the leading edge. While entire chord lengths are actually measured, the exclusions in the pitch derivations negate the effect of the edge contours on the pitch measurements.

3.2.4.1 Propeller hub inspection (Compliance Form Sections 2 and 3). Conduct the propeller hub inspections required to record in section 2 and 3 of the Compliance Forms.

CAUTION!

The propeller hub bore inspection shall be accomplished before any other inspections or tests required in this work item. If the propeller fails this inspection, the contractor shall not perform any additional tests or inspections without approval of the KO.

3.2.4.2 Surface finish (Compliance Form Section 4). Visually identify and record the roughest surface finish on each blade and the hub/bore. Mark all areas on the propeller with out-of-tolerance surface finishes.

NOTE

As part of Section 6 of the compliance forms, a sketch or photograph showing

UNSAT surface finish may be provided in lieu of a filled-in Section 4 of the compliance forms.

3.2.4.3 Balancing (Compliance Form Section 5). Unless a visual inspection reveals an obvious out-of-balance condition, conduct and record results from a static balance test.

WARNING!

There shall be no machining, welding or material addition or removal to the propeller after final balance check is completed.

3.2.4.4 Surface inspection (Compliance Form Section 6). Conduct a visual inspection of the propeller and mark up the accompanying figure on Compliance Form Section 6.

NOTE

This requirement may be fulfilled via the VTI and is not intended to be a duplicate of that earlier effort.

3.2.4.4.1 Perform a dye penetrant inspection over 100 percent of the blade, fillet, and hub surfaces in accordance with ASTM E1417 while using ABS Part 7, Appendix, Section 10, Table 1 as acceptance criteria. The inspection shall be performed by a certified Level II NDT Technician.

3.2.4.4.2 Document all propeller defects resulting from the visual and dye penetrant inspections in

Compliance Form Section 6. These defects shall be indicated by type, size, and acceptability on visual inspection sheets. Each propeller will require individual inspection sheets for the pressure face of the blades, suction face of the blades, the fillet, and the hub.

3.2.4.4.3 All visual defects, even though deemed acceptable, shall be documented on the inspection report.

3.2.4.4.4 A copy of the dye penetrant inspection report shall be included as part of the final inspection report.

3.2.4.4.5 Provide photo documentation to the KO during in-process welding repairs of the casting (if applicable) and any discontinuities of the propeller casting during dye penetrant inspection. Each photograph shall include the propeller serial number and date the photograph was taken. The color photographs shall be taken with a digital camera and the images provided electronically in “jpg format” to the KO during:

• the dye penetrant inspection showing any linear/non-linear discontinuities of the propeller casting.

• repair of the propeller whenever welding is required and approved.

3.2.4.5 Geometrical/dimensional data (Compliance Form Section 7). Measure and record the following:

a. Propeller blade radii

CAUTION – ALL PITCH MEASUREMENTS

Shorter, yet in-tolerance chord lengths may yield pitches outside of those presented in the Compliance Forms. Likewise, measuring equipment (other than CMM) may require “exclusions”, i.e., small lengths from each end (up to a half inch permissible), to ascertain pitch measurements. With review and approval from the KO, adjustments to the reference pitches and tolerance bands may be considered. The Contractor must demonstrate how the numbers were adjusted to determine the proposed figures and be replicable by the Coast Guard to gain approval.

b. Local pitches (three equal segments)

c. Section pitch

d. Mean pitch per blade

e. Mean propeller pitch

f. Blade section widths

g. Maximum thickness at prescribed stations (see drawing table of offsets to make location determination)

h. Track deviation/rake

i. Edge conditions

j. Angular spacing of blade center axis

k. Surface finish of blade, hub and bore areas

l. Surface inspection

m. Hub bore inspections and fit

n. Material composition

o. Balancing data

p. Fairness

3.2.4.6 Pre-overhaul/repair report. Provide the inspection results from above via the applicable portions of the Compliance Forms, highlighting all out-of-tolerance measurements, and note the necessary repairs to be made, for KO review and approval. Indicate anticipated effects on propeller performance (if any) from the discrepancies.

3.3 Propeller overhaul/repair. If a Change Request has been authorized and released by the KO, the

Contractor must make all recommended repairs (or as amended by the KO) for the affected propeller(s).

3.3.1 General notes for overhaul/repair.

3.3.1.1 Critical areas: The critical areas are described in section 1.5.5 (b), Figure 3 of the ABS Part 7.

3.3.1.2 Severity Zones: The following apply to the welding in Severity Zones as defined by ABS Part 7, Section 10, paragraph 1.5.5 (b), and subparagraphs for High-Skew propellers.

3.3.1.2.1 Zone A is the area on the pressure face contained within the blade root fillet and a line running from the junction of the leading edge with the root fillet to the trailing edge at the 0.9R and passing through the mid-point of the blade chord at 0.7R and a point situated at 0.3 of the chord length edge at

0.4R. It also includes an area along the trailing edge on the suction side of the blade from the root to 0.9R and with its inner boundary at 0.15 of the chord lengths from the trailing edge.

3.3.1.2.2. Zone B constitutes the whole of the remaining blade surfaces.

3.3.1.3 Welding required to repair cavitation erosion in the critical area, but not to include the blade fillets located between the 0.2 and the 0.25 radius, shall be undertaken as the contractor deems necessary.

3.3.1.4 Welding repairs of the propellers shall meet the requirements of ABS Part 7 Appendix 1, Section

10.

3.3.1.5 The contractor shall document all welding performed on the visual inspection sheets for each propeller. Each weld shall be dimensionally identified by location, length, width, and depth.

3.3.1.6 Material removed to affect balance shall be taken from the suction face on as large an area as practicable and shall not approach the leading or trailing edges within (10) ten percent of the blade width.

3.3.1.7 Care shall be taken to assure that removal of material shall not cause the tolerances for thickness, surface contour, edge contour, width or pitch to be exceeded.

3.3.1.8 There shall be no machining or grinding on the propeller after final balance check.

3.4 Post-repair/overhaul inspections and tests.

3.4.1 Only for those initial inspection and test results affected by repair and/or overhaul must the

Contractor redo those inspection(s) and test(s).

3.4.2 Record all final results on a second set of Compliance Forms and submit to the KO for review and approval. Provide a brief written narrative as part of the final submission detailing each propeller’s finished condition.

3.5 Ensure the proper markings exist (see Compliance Form Sections 7.a-j) or affix those that are missing on the propeller hub.

3.6 QA inspection. Following KO acceptance and approval of the final Compliance Forms and prior to conducting any preservation, packing and packaging, the Contractor must schedule Coast Guard SFLC

QA inspection. A copy of the final Compliance Forms must be provided to the Coast Guard QA

Representative upon arrival for final inspection.

4. NOTES

4.1 Post-repair/overhaul activities. Refer to the General Requirements work item, Section 5, for the preservation, packaging, packing, and shipping requirements.

4.2 Reference sources. Refer to General Requirements work item, Section 6, for referenced document sources.