0105_A_Tank Hatch Preservation_RevA.doc

USNS Lenthall

( TAO 189 )

1.0 ABSTRACT

1.1 This item describes the requirement to preserve thirteen (13) Tank hatches located on the tank deck.

2.0 REFERENCES/ENCLOSURES

2.1 References

2.1.1 MSC Drawings, 167-6580087, “Hatch, Scuttle, AVHC & Tank Cleaning Openings.”

2.2 Enclosure

2.2.1 Cross Section of Gasket Material (2 Pictures)

2.2.2 Sample Chalk Test (1 Picture)

2.2.3 Hatch Opening Components (1 Picture)

2.2.4 Enclosure 2.2.4 – Tank Names and Locations

3.0 ITEM LOCATION/DESCRIPTION

3.1 Location/Quantity

3.1.1 Location: Main Deck, FR 18-57

3.1.2 Quantity: Thirteen (13) total Cargo and Ballast Tank hatches to be designated upon arrival of the vessel by the Chief Engineer.

3.2 Gasket Description

3.2.1 Hatch Gasket -Semi-Hard Rubber Gasket Material 40 mm x 40 mm x 3750 mm. See Enclosure 2.2.1 for photographs of gasket cross section.

3.3 Paint Scheme

4.0 GOVERNMENT FURNISHED EQUIPMENT/MATERIAL/SERVICES

Amercoat T-10 Solvent

8 Gal

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 including but not limited to GTR’s 1-7, and 25.

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

6.0 QUALITY ASSURANCE REQUIREMENTS: None Additional

7.0 STATEMENT OF WORK REQUIRED

7.1 Contractor to provide all labor, tools and equipment to remove tank hatch covers and all associated hardware, including but not limited to the yoke, hand wheel and ullage cover from their position and transport them to the blast shop.

7.1.1 While tank hatch covers are removed, set up safety precautions to prevent any unauthorized entry into the tank.

7.2 Surface Prep/Coating Application

7.2.1 SSPC-SP-10 “Near White Metal” blast all removed Cargo and Ballast Hatch Covers, yoke, hand wheel and associated hardware that listed in para 3.0.

7.2.2 SSPC-SP 3 “Power Tool Clean” all tank coaming of tanks listed in para 3.0 to include but not limited to:

7.2.2.1 Vent pipe from coaming to flange

7.2.2.2 Drop bolt pad

7.2.2.3 Locking pin pad

7.2.2.4 Pin pad

7.2.3 Conduct a surface preparation checkpoint in the presence of the MSC Paint Representative to verify proper surface preparation.

7.2.4 Upon approval of surface preparation and/or the application of the previous coat, install three (3) each coats of paint using paint scheme detailed in Paragraph 3.3.

7.2.5 Tank Cover

7.2.5.1 The hand wheel with have a top coat to match the ship’s color scheme for tank contents. DFM hand wheel is to have a Top Coat of Yellow, JP-5 DFM hand wheel is to have a Top Coat of Purple and Ballast DFM hand wheel is to have a Top Coat of Green.

7.2.5.2 After the top coat of light gray, manufacture new tank nameplates, using the following as an example:

No. 8 S SW Ballast

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7.2.6 Tank Coaming

7.2.6.1 After the top coat of light gray, stencil the coaming with TANK ENTRY PROHIBITED WITH OUT PERMISSION FROM THE MASTER, using existing as template.

7.3 Contractor is to remove each of the Gaskets from the Cargo and Ballast Tanks Hatches before blasting. Using removed Gasket as a template manufacture Cargo Hatch Gaskets. Size and dimension of the Hatch Gasket is detailed in Paragraph 3.2.1 and photographs of the cross section can been viewed in Enclosure 2.2.1. Dimensions and details of the Hatch Covers are outlined in Reference 2.1.1.

7.3.1 Install the Hatch Gasket using contact cement. When installed gasket ends are make contact with each other to make the gasket air/fluid tight.

7.4 Reinstall the hatch cover and conduct an operation test of the removed Cargo Hatches to verify that the Hatches move freely and do not bind.

7.5 Manufacture seven (7) each new drop bolt and wing nut and install with new pins.

7.6 Conduct a chalk test of each Cargo Hatches to verify that the Hatch Cover is making contact with the lip of the Hatch Cover Upright. Verify that 100% contact is being made. Sample of acceptable 100% Chalk test is shown on Enclosure 2.2.2.

7.7 All dirt and debris resulting from this work item shall be removed from the ship daily and all areas left clean and in good order.

8.0 GENERAL REQUIREMENTS: None Additional

Enclosure 2.2.1-Cross Section of Gasket Material (2 Pictures)

Enclosure 2.2.2-Sample Chalk Test (1 Picture)

Enclosure 2.2.3 - Hatch Opening Components (1 Picture)

Enclosure 2.2.4 – Tank Names and Locations

CARGO TANKS

SW BALLAST TANKS

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