MI_24500_JPH_0908_378E_Liaaen_Single_Prop_rmv_install.pdf

ITEM 1: REMOVE AND REINSTALL PROPELLER HUB FROM TAILSHAFT

MI_24500_JPH_1207_378

1 SCOPE

The intent of this item is to remove and reinstall the propeller hub from the Tailshaft. This specification is for one shaft (port or starboard). It can be ordered multiple times as required for a maximum of two (2) times (once for starboard and once for port shafting).

Government Furnished Property: NONE

2 REFERENCES

Coast Guard Drawings:

378-FRAM-W 243-25, Rev -; Tailshaft (Superseded by 378-FRAM-W-243-27) 378-FRAM-W 245-10, Rev -; PROPELLER HUB ASSEMBLY CROSS SECTION MODEL D125/4

Applicable Documents:

CG Tech Pub 3258; Manufacturers Instruction Book, SWBS Group(s) 243-244 CG Tech Pub 3259; Manufacturers Instruction Book, SWBS Group(s) 245

3 REQUIREMENTS

The Contractor shall provide all labor and material to accomplish the following in accordance with the General Requirements:

3.1 GENERAL INSTRUCTIONS

3.1.1 Any o-ring (or custom o-ring made out of stock) that is cut and then requires rejoining shall not be glued back together, but rather joined together by a vulcanizing process. This vulcanizing requirement has come about due to a rash of failed glued joints that required emergency dry-docking of numerous Cutters. On a case by case basis, and only on non-underwater sealing joints, and if supported by OEM, the Contractor may appeal this vulcanizing requirement. Coast Guard reserves the sole right to approve or disapprove such appeals.

3.1.2 The propeller blades have already been removed, the propeller hub has been removed with the tailshaft, and the shafts measured and inspected in other work items. Skim cutting the tailshaft liners (if required) will necessitate removal of the propeller from the tailshaft.

3.1.3 The propeller blades have already been removed, the propeller hub has been removed with the tailshaft, and the shafts measured and inspected in other work items. Skim cutting the tailshaft liners will necessitate removal of the propeller from the tailshaft and removal of the shaft coating. Removal of the coating is covered in another work item and is not included in the scope of this work.

3.1.4 The Contractor shall provide and use a OEM certified/licensed Technical Representative to ensure all work is performed satisfactorily. Technical Representative shall be present for all disassembly, inspection, and reassembly of the Propeller to Tailshaft.

3.1.5 Cleanliness is of prime importance. If cleanliness is not maintained at all times, work may be suspended by the Contracting Officer on the advice of the Technical Representative.

3.1.6 Only workers with clean clothes and tools shall be assigned to work around the propeller’s open hub mechanism.

3.1.7 All lifting equipment, chain blocks, rope, nylon slings, and other equipment/tools shall be washed clean prior to use on the CPP system to prevent dirt from falling into the system.

3.1.8 When not actually working on the hub and upon its removal from the tailshaft, it shall be wrapped with plastic sheeting, then taped closed to exclude dirt and moisture.

3.2 PROPELLER HUB REMOVAL AND REINSTALLATION (All part numbers in paragraph 3.2 refer to CG Dwg 378-FRAM-W 245-8 which is also identical to Dwg 15807-D of TAB 1, CG Tech Pub 3259)

3.2.1 In accordance with CG Dwg 378-FRAM-W 245-10, CG Tech Pub 3258, and CG Tech Pub 3259 perform the following steps:

3.2.1.1 Fabricate a lifting bracket to hold the propeller hub. Consult the Technical Representative for the design details. Support Propeller Hub for removal with fixture.

3.2.1.2 Remove the Prop Shaft Flange Cover (PC# 27) by removing capscrews (PC# 66) and washers (PC# 7).

Clean and thoroughly examine the Prop Shaft Flange Cover before reassembly, since this cover when installed provides a critical oil seal/boundary.

3.2.1.3 Remove the four (4) tapered pins and collar assemblies (PC# 25 & 26) by the following process

a. removing snapring (PC# 111)

b. remove plate (PC# 26)

c. remove capscrew (PC# 63)

d. reinstall plate (PC# 26)

e. insert capscrew (PC# 63) through hole in plate (PC# 26)

f. tighten capscrew (PC# 63) until tapered pin (PC# 25) breaks free of taper

3.2.1.4 Break lock bar (PC# 23) from flange bolts (PC# 22).

3.2.1.5 Remove the twelve (12) propeller to tailshaft flange bolts (PC# 22).

3.2.1.6 Maintaining control and alignment separate the propeller from tailshaft and access oil tube to operating rod connection.

3.2.1.7 Unbolt oil tubes and rig propeller away from tailshaft to secure clean area. Ease hub off tailshaft horizontally being careful to not shear off taper bushings (PC# 24).

3.2.1.8 With hub removed, tap or jack taper bushings (PC# 24) forward out of tailshaft.

3.2.1.9 Under Technical Representative guidance clean and inspect the now accessible oil tubes (remove from tailshaft), operating rod, and bushings. Provide a CFR with inspection results and dimensions on any wear parts.

3.2.2 Upon completion of liner repairs reinstall propeller to the tailshaft in accordance with CG Dwg 378-FRAM- W 245-10, CG Tech Pub 3258, and CG Tech Pub 3259.

3.2.2.1 Renew any seals, o-rings, or gaskets that are disturbed.

3.2.2.2 Clean and inspect all bolts, pins, and fasteners for damage.

3.2.2.3 For the twelve (12) propeller to tailshaft bolts, the tapered pins, and the tapered bushings test for cracks using dye penetrant. Inspect bolt landings (on tailshaft) for these bolts.

3.2.3 Mount hub on tailshaft insuring all mating surfaces are clean and free of burs. Place hub on tailshaft pilot and install bolts, coated with molycote, hand tight. Align dowel pin holes. Install bushings (PC# 24). Install dowel pin (PC# 25). Install capsrew (PC# 63) into dowel end and turn out to secure dowel pin assembly against plate (PC# 26). Install new snap ring (PC# 111).

NOTE: If the same hub is re-installed on the same tailshaft, the dowel pin holes should align. However if a new propeller or new tailshaft is introduced the bushing through hole (through tailshaft into hub) must be reamed true and a new custom sized bushing procured or fabricated. Reaming of bushing’s hole or fabrication of new bushing and/or tapered pin if warranted would be the subject to a modification to the contract (Work Request or Quick Chit) that would be negotiated between the contractor and contracting officer.

3.2.4 Tighten the twelve (12) propeller to tailshaft flange bolts. Renew and install lock bars (PC# 23) on the twelve

(12) propeller to tailshaft bolts after final bolt torquing.

3.2.5 Reinstall propeller shaft hood with new sealing rings. Position hood to orientate access holes for the drain plugs. If not already existing the hole in hood shall have a distinguishable threaded plug that can be found and removed to gain access to drain plugs for shafting. Consult the Technical Representative for the design details.

NOTE: Pay particular attention to the sealing surfaces and sealing rings while installing the Prop Shaft Flange Cover (PC# 27). This cover provides an oil tight boundary and leakage is unaccepatbile and would require a drydocing and shft disassembly to cure if leakage occurs while Cutter is waterborne.

3.2.6 Once shaft hood is installed fill the cavity with tallow or an acceptable equal determined by Technical Representative.

3.2.7 At completion of provide lifting bracket to CG Inspector for future use as Government provided tool.

3.3 The shafts shall be recoated and re-installed, the bearings reinstalled, propeller blades reinstalled, and other related shaft work performed in other work items. This item’s bid shall reflect the work of this item only.

3.4 Coordinate all inspections with the designated Coast Guard Inspector to minimize production delays.