BUSL-49A_Main_Deck_Restore.pdf

49A BUSL 49416

WORK ITEM 1: Aft Main Deck (Buoy Deck) Plating, Renew

1. SCOPE

1.1 Intent. This work item describes the requirements for the Contractor to renew deteriorated portions of the aft (buoy) deck.

1.2 Government-furnished property.

None

2. REFERENCES

COAST GUARD DRAWINGS

1. 49A BUSL 130-002, Rev. F MAIN DECK PLATING AND FRAMING

Note that sheet 3A and 9A of this drawing are not applicable to this boat.

2. 49A-BUSL 631-1, Rev. F PAINTING SCHEDULE

3. 49A-BUSL 114-3, Rev. F CHAIN GUARD/RUB RAILS

4. 49A-BUSL 120-2, Rev. D WATERTIGHT BULKHEADS

5. 49A-BUSL 200-2, Rev. A MACHINERY ARRANGEMENT

6. 49A-BUSL 304-1, Rev. D ELECTRICAL CABLEWAYS

7. 49A-BUSL 320-3, Rev. G POWER/LIGHTING DECK

8. 49A-BUSL 512-3, Rev. - HVAC SYSTEM DIAGRAM

9. 49A-BUSL 523-1, Rev. C DECK WASHDOWN SYSTEM

10. 49A-BUSL 528-1, Rev. B PLUMBING HATCH DK DRAIN

11. 49A-BUSL 555-1, Rev. C FIXED CO2 SYSTEM

12. 49A-BUSL 556-2, Rev. E BUOY HNDLG HYD SYSTEM

13. 49A-BUSL 611-2, Rev. C HULL FITTING DETAILS

14. 49A-BUSL 612-2, Rev. C RAILS & LIFELINES

15. 49A-BUSL 635-1, Rev. D HULL INSULATION SCHED

16. 49A-BUSL 637-1, Rev. D HULL SHEATHING DETAILS

17. 49A-BUSL 671-1, Rev. D MISC STOWAGE DETAILS

COAST GUARD PUBLICATIONS

Surface Forces Logistics Center Standard Specification 0000 (SFLC Std Spec 0000), 2014, General Requirements

Surface Forces Logistics Center Standard Specification 0740 (SFLC Std Spec 0740), 2014, Welding and Allied Processes

Surface Forces Logistics Center Standard Specification 6310 (SFLC Std Spec 6310), 2014, Requirements for Preservation of Ship Structures

OTHER REFERENCES

MIL-PRF-24647, Jun 2013, Paint System, Anticorrosive and Antifouling, Ship Hull

The Society for Protective Coatings (SSPC)/NACE-International (NACE) Joint Surface

Preparation Standard SSPC-SP 10/NACE No. 2, 2007 Near-White Blast Cleaning

The Society for Protective Coatings (SSPC) Surface Preparation Specification No.11 (SSPC-SP

11), 2012, Power Tool Cleaning to Bare Metal

3. REQUIREMENTS

3.1 General.

3.1.1 CIR.

None.

3.1.2 Tech Rep.

None

3.1.3 Protective measures - general. The Contractor shall furnish and install all protective coverings to seal off and protect all vessel's components, equipment, and spaces beneath the work area against contamination and impact from objects dropped from above during the performance of work. These protective means shall include plywood crating or covers for all of the machinery beneath the area being worked on as well as tarps or other protective means to seal the machinery from dust, ground metal, welding debris and paint. Fire cloth and stove piping will have to be installed in various areas to protect the electrical wiring. Upon completion of work, the Contractor shall remove all installed protective measures, inspect for the presence of contamination, and return all contaminated equipment, components, and spaces to original condition of cleanliness.

3.1.4 Interferences: The Contractor shall handle all interferences in accordance with SFLC Std Spec

0000, paragraph 3.3.5 (Interferences). In addition to guidance provided by the drawings (Ref. 3-17), the

Contractor shall take photos and or videos in order to ensure that these are put back into place properly.

Known interferences on deck or immediately below deck that will have to be removed in whole or in part and preserved for re-installation or replaced with new material include, but are not limited to:

Electrical wiring, cableways, hangers, lighting and related components

Deck washdown piping and associated penetrations and stuffing tubes

Hatch drain

Two machinery space exhaust fans, hoods and related spools, wiring and components including damper control stuffing tubes and related components.

CO2 fire suppression piping, nozzles and related fittings

Buoy handling hydraulic system piping and related penetrations and stuffing tubes

Insulation on the machinery space overhead including material boxing the deck stiffeners

Perforated aluminum sheathing on the machinery space overhead, riveted in place

Deck lockers and foundations

Cross deck winches foundations

Oxyacetylene cylinders foundations

Sixteen recessed deck sockets (to be reused)

Two bull chain recessed deck socket (if required – to be reused)

Two bitts(to be reused), Two chocks (to be reused), Handrail stanchions (to be reused), and

The quick acting watertight hatch going to the engine room (to be reused)

3.1.5 Equipment to be protected: Items in machinery space and lazzarette that will be exposed to damage and must be protected include:

Main engine, transmission and associated equipment

Generator and associated equipment

Fresh water tanks

Pumps, compressors and related equipment and fittings

Switchboards

Sewage Tank

Batteries

3.2 Existing deck plating removal and restoration. The Contractor shall crop off and restore the deteriorated existing main deck plating and longitudinals from the existing transverse seam 15 inches forward of frame 4 to a new seam aft of WT Bhd. 2 in accordance with Coast Guard Drawing Reference

1. The Coast Guard proposes that the new aft seam shall follow the existing seam between part(s) 26

(Zone 18-G, Ref. 1) and 27 (Zone 20-B) and part 92 (Zone 22-E) at 3 inches aft of Bhd. 2 from centerline to a point 36 inches of centerline P/S, thence the 9 inch radius P/S to the tangency 12 inches aft of Bhd. 2, thence straight outboard P/S. This results in a replacement area approximately 14’-3” long by 16’-3” abeam.

This is illustrated in the attached sketch which also includes the ultrasonic thickness readings at their approximate locations. This seam was chosen based on the results of the ultrasonic measurements of plate thickness and to preserve the two aft bull chain tie-downs and the forward inserts for the A-Frame undisturbed and is preferred.

However, depending on the exact as-found condition of the deck and other practical considerations, the aft seam may be located up to five inches further aft than noted above at the local Coast Guard

Representative’s option, and the seam run may be straight across the deck. In addition to the restoration above, the isolated deteriorated area around shot 42 shall be restored with an insert if not included in the above restored area. The insert shall have minimum radii of 3 inches.

Note that the deck plating generally extends beyond the freeboard plating (see detail at 19-H, Ref. 1).

The Contractor may propose to remove the entire deck plating to the outer edge of the plate by cutting the existing welds between the deck plating and the side shell or may cut the plating inboard the joint and establish a new seam near the deck edge. This seam shall be at least 3 inches inboard of the deck edge.

The deck plating is continuously welded to the longitudinals. Therefore, the Contractor shall remove both the plating and the existing longitudinals and shall fabricate a new deck comprising the plating and the longitudinals. The existing transverse frames shall be left in place. Areas of transverse framing found to be deteriorated with loss of more than 25% of original thickness shall be restored.

3.2.1 Welding and NDI. The Contractor shall perform all welding and nondestructive inspection (NDI) in accordance with SFLC Std. Spec 0740, Appendix C.

3.6 Preservation requirements. The Contractor shall preserve the new structure and replaced components as follows:

3.6.1 Surface preparation. Prepare surfaces by one or a combination of the following surface preparation methods:

ABRASIVE BLASTING MECHANICAL CLEANING

Abrasive-blasting to SSPC-SP10/NACE No. 2, using grit conforming to MIL-A-22262 (1.5 to 2.5 mil anchor profile).

Power tool cleaning to a SSPC-SP 11 (1.0 mil anchor profile).

3.6.2 Inspection. After surface preparation and before coating application, perform a visual inspection of the prepared surfaces, and submit a CFR.

3.7 Surface coating. The Contractor shall coat all new and disturbed interior surfaces in accordance with

SFLC Std Spec 6310 and Ref. 2.

NOTE

List of authorized suppliers for “High Build Epoxy” coatings is provided in

SFLC Std Spec 6310, Appendix C (Authorized Coatings for Use on Cutters and Boats).

3.7 In-process quality control measures. The Contractor shall abide by all the safety, preservation, and quality control requirements specified in SFLC Std Spec 0000, paragraph 3.2.4.2 (In-process QC measures for “critical-coated surfaces). Surfaces being preserved are considered “critical-coated surfaces”.

3.8 Compartment air test. The Contractor shall perform an air hose test on the deck using SFLC Std.

Spec 0740, Appendix C as guidance. Submit a CFR.

3.9 Pull Tests. The Contractor shall perform pull tests on all deck sockets to 150% of the rated load (Note

15 and 16 of Ref.1 ); and on the restored bitts and chocks.

4. NOTES

The following interferences are due to be accomplished under Dry Dock Contract HSCG40-15-C-

P30337:

Fendering

Two main engine mufflers and related exhaust piping

A generator muffler and related exhaust piping

Cross deck winches

Oxyacetylene cylinders

The following surface preparation is due to be accomplished under Dry Dock Contract HSCG40-15-C-

P30337

All disturbed exterior surfaces

5. FIGURE

Deck Replacement Sketch: Attached PDF “49416AftDeckReplacement.pdf”.