0958_A_Propeller_Clean_and_Polish_-_In_Water_(0.5YR).doc

AH CLASS

(T-AH 19/20)

DRYDOCKING & UNDOCKING

N32205-XX-R-XXXX

19 SEP 2018

ITEM NO. 958

CATEGORY "A"

MSC/N75/SWI

PROPELLER CLEAN AND POLISH – IN WATER (0.5YR)

1.0 ABSTRACT

1.1 This work item describes the requirements to clean & examine the ships propeller(s) and suction grates while waterborne.

2.0 REFERENCE/ENCLOSURE

2.1 Reference:

2.1.1 Navsea Dwg. No., 801-5980060, Docking Plan

2.1.2 NASSCO Dwg. No., 390-203-004 Propeller Details

2.1.3 NASSCO Dwg. No., 390-203-007 Skewed Propeller Details

2.1.4 NSTM Chapter 245, Propellers and Propulsors

2.2 Enclosure:

2.2.1 Blade & Hub Inspection forms

3.0 ITEM LOCATION/DESCRIPTION/QUANTITY

3.1 Location:

Underwater hull

3.2 Description:

3.3 Quantity:

One (1 ea)

4.0 GOVERNMENT FURNISHED EQUIPMENT/MATERIAL/SERVICE:

4.1 Government Furnished Equipment (GFE): None

4.2 Government Furnished Material (GFM): None

4.3 Government Furnished Services (GFS): None

5.0 NOTES:

5.1 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.

5.2 The contractor and all subcontractors regardless of tier are advised to review other work items under this contract 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.

5.3 Per SMS Procedure 2.2-017-ALL Shipboard Energy Efficiency Management Plan (SEEMP) requires a complete underwater hull and propeller inspection every six months and order hull/propeller cleaning if necessary.

5.4 Per ref 2.1.3, inspection intervals should be conducted approximately every 6 months and coincide with ship in-port periods and but may be extended past this time frame based on the ship’s scheduled operating and maintenance schedules.

6.0 NOT USED

7.0 STATEMENT OF WORK REQUIRED

7.1 Remove and replace all interferences, rig and unrig, stage and unstage, make all disassemblies and subsequent reassemblies. Provide and operate equipment, and supply all services and assistance to accomplish the thorough underwater cleaning & examination of the vessels propellers & sea chests in accordance with ref 2.1.4 and the manufacturer’s requirements.

7.2 Conduct a Pre-Dive Planning Meeting with the Divers Rep, Master, Chief Engineer and MSCREP in attendance. The meeting agenda and discussion shall, at a minimum, cover:

a) Confirm there is no record or indication of abnormal deterioration or damage to underwater body, propeller, rudder, stern frame, stern seal, underwater structure, or sea valves.

b) Discuss means of communication between the bridge, dive team and engine room (direct communications via sound powered phones are preferred).

c) Discuss procedure/plan for emergencies.

d) Discuss the in-water clarity (visibility) and the current cleanliness of the underwater hull. Determine if additional or spot cleaning will be necessary.

e) Discuss vessels anticipated drafts, pier side clearance and underkeel clearance at the time of the cleaning.

f) Discuss impact of tides & currents on divers and the examination.

g) Discuss anticipated duration of the underwater work.

7.3 Clean & polish the ships propeller(s) & sea chest suction grates as shown in references 2.1.1 through 2.1.3 in accordance with ref 2.1.4 and the Manufacturer requirements.

CAUTION: Blade seal areas of controllable pitch propellers (CPP) shall be masked off prior to any cleaning to prevent the entry of debris into the seal areas.

7.4 Remove all sea growth (e.g.: calcium deposits, sea grass, barnacles, etc.) from the propeller(s) and suction grates. Cleaning shall not result in damage to the propeller or the removal of propeller material. Utilize the approved cleaning methods identified below:

a) Hydroblasting (high pressure water jet cleaning) may be used on all propellers and fairwater surfaces. Perform hydroblasting immediately upon drydocking and before marine growth has dried. At NO TIME shall hydroblasting on unpainted propeller surfaces exceed 10,000 psi or 2,000 psi for painted surfaces. WARNING: In no case shall the seal areas of a CPP be hydroblasted.

b) Hand Cleaning (Scraping, Brushes, Pads, Etc.). Plastic or hardwood scrapers, nylon & polypropropylene brushes (e.g. A-1 and A-2) and hand held plastic conditioning pads (e.g. Scotch-Brite “green”) are acceptable for cleaning all propeller & sea chest suction grate surfaces. It is preferred that the final cleaning operation of propeller blade edges (within 3 inches) be cleaned by hand with plastic surface conditioning pads. Do not attempt to round the edges of the blades with brushes and discs.

c) Powered Cleaning Processes. Only nylon and polypropylene brushes (e.g. A-1 and A-2) and non-abrasive plastic surface conditioning discs (e.g. Scotch-Brite “green”) may be used with power tools on less sensitive areas of painted propellers and sea chest suction grates. Care is to be used not to remove markings. Powered cleaning methods SHALL NOT be used within 3 inches of blade edges, tips, cusps, fillets (excluding hub to blade interface), areas of high curvature, or other sensitive areas of a propeller. When cleaning the outer periphery of the blades, the brushes and discs must be kept flat on the blade surface.

7.5 Examine the ships propellers, rope guards, rudders, sea chest suction grates and shaft seals shown in references 2.1.1 and 2.1.2 in accordance with ref 2.1.3 and the Manufacturer requirements:

7.5.1 Externally examine all visible parts of the propeller(s). Inspect the hub, blades and blade edges for cracks, curling, porosity, cavitation erosion, nicks, dents, bends, cable marks, flat spots, ridges, punch marks, gouges, etc… Verify that the propeller is free of damages which may cause the propeller to be out of balance.

7.5.2 Visually examine CPP propeller(s) for blade seal leaks (if applicable).

7.5.3 Visually examine stern bearing(s) & rope guards for fishing nets, wire rope, oil seal leaks (if applicable), etc...

7.5.4 Visually examine rudders for damage, missing hardware, missing inspection plates, wire rope, etc...

7.5.5 Visually examine all sea chest suction grates for damage, missing hardware, obstruction, debris, etc…

7.5.6 Submit photographs and a completed enclosure 2.2.1 recording any observed damage or deficient conditions. Submit to the MSCREP during the survey.

7.6 Upon satisfactory completion of all work the contractor shall leave the propeller(s) & sea chest suction grates in a ready for service condition.

7.7 Reports

7.7.1 When cleaning & examination reveal any deficiency a condition report is to be submitted to the MSCREP with recommended repair and parts required. Submit three (3) typewritten copies to the MSCREP.

7.8 Manufacturer’s Representative: None

7.9 Preparation of Drawings: None

8.0 GENERAL REQUIREMENTS

8.1 None additional

Blade & Hub Inspection

Enclosure 2.2.1

Blade & Hub Inspection

Enclosure 2.2.1

Blade & Hub Inspection

RISK

Frequency of Occurrence Over Time

A

Likely B

Probable C

May D

Unlikely

Risk Assessment Codes

1 – Critical 2 – Serious 3 – Moderate 4 – Minor 5 - Negligible

RAC SCORE:

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