USNS MARY SEARS
T-AGS 65
HULL STRUCTURE Solic. No. MLL-16-T65-0001
August 29, 2016
ITEM NO. 0112 CATEGORY “A” USMMI/MLL/RCS
MAKE REPAIRS TO THE PORT POTABLE WATER TANK
1.0 ABSTRACT:
1.1Provide service to clean and repair the port potable water tank bulkhead and support framing, then recoat, and hyper-chlorinate potable water tank.
2.0 REFERENCES:
2.1NAVSEA Drawing 085-6783017; Capacity Plan
3.0 ITEM LOCATION/DESCRIPTION:
3.1Location/Quantity:
3.1.1Location:
3.1.1.1Forward Pump Room (3-73-0)
3.1.2Quantity: One tank
3.2Description: Potable Water Tank 3-77-2
4023 gallons
862 sq. Ft.
4.0 USMMI FURNISHED EQUIPMENT/MATERIAL/SERVICE:
4.1USMMI Furnished Equipment (USMMIFE): None
4.2USMMI Furnished Material (USMMIFM):
4.2.1Amercoat 133 off-White Paint. 20 gallons.
4.3USMMI Furnished Services (USMMIFS):
4.4USMMI Furnished Information (USMMIFI):
4.4.1Drawings are available on board the ship
5.0NOTES:
5.1The 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 GTRs including but not limited to GTRs 1-7.
5.2The 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.
5.3The contractor shall comply with all requirements of equipment tag-out program as established by COMSCINST 3540.6, as amended, section 15.2.2, Engineering Operations and Maintenance Manual. The Chief Engineer is to administer the program. Prior to the start of work, the contractor shall contact the USMMI Port Engineer and / or the Chief Engineer to coordinate the implementation of the tag-out program for the entire performance period of this item. The prime contractor shall be responsible for compliance by both prime and subcontractor personnel.
5.4Tank forward bulkhead and stiffenersare bowed outward approximately 25-40mm with the upper gussets bent at two of the frames.
6.0 QUALITY ASSURANCE REQUIREMENTS:
6.1Material Requirements:
6.1.1The contractor shall utilize paint products which are compatible with existing PPG coatings. The product utilized must be safe for use in potable water systems.
6.2Qualification/Process Requirements:
6.2.1The weld procedure and the welders must be reviewed and approved by the ABS attending Surveyor prior to beginning any hot work for this repair.
6.3Inspection/Test Requirements:
6.3.1If replacement is required the Contractor is to provide ABS certificates for the plate to be used in this repair.
6.3.2Any fit-ups, first pass, back gouge and final pass are to be inspected by the ABS surveyor. The post weld testing will include NDT of the welds and a hydrostatic test of the tank.
7.0 STATEMENT OF WORK REQUIRED:
7.1Arrangement/Outfitting:
7.1.1The port potable water tank is to be drained by the crew. The Contractor is to temporarily remove the manhole cover on port side of the potable water tank. The tank and surrounding area are to be certified safe for entry and safe for hot work.
7.1.2All exterior items such as the escape scuttle ladder, level gauges, speaker, etc. which are mounted on the front of the potable water tank which would interfere with the repairs are to be temporarily removed. Once repairs are completed these items are to be reinstalled in their original locations.
7.2Structural:
7.2.1The Contractor is to develop a working drawing showing the locations of the damage and the recommended repair method. If replacement is required, the plate, bracket and frames which will be required to make a permanent repair are to be documented in the drawing.
7.2.2The sketch, plate material certification, welding procedure and welder qualifications are to be provided to the attending ABS surveyor for his review and approval.
7.2.3Once the condition of the tank has been determine and ABS has approved the repair process, the contractor is to make permanent repairs to the tank bulkhead and stiffeners by either fairing the bulkhead and stiffeners back to the original position or cropping out the defective brackets, frames, and bulging bulkhead and installing new.
7.3Mechanical/Fluid: None additional
7.4Electrical:
7.4.1All electrical interferences are to be secured and tagged out by ship’s crew.
7.5Electronics: None additional
7.6Preparation of Drawings:
7.6.1The Contractor is to develop working drawings which are to be presented to the USMMI Port Engineer and the attending ABS Surveyor for their review and approval.
7.7Inspection/Test:
7.7.1See the requirements in 6.0 above.
7.8Painting:
7.8.1Drain all potable water and discard.
7.8.2Open potable water tanks, certify “Safe for Entry”. If required, certify “Safe for Hot Work”.
7.8.3Clean tank surfaces by high pressure blast washing at 3200 PSI with Dev prep 88 or similar product.
7.8.4Provide method to pump and dispose of wash liquids
7.8.5Power tool clean rust and blisters not removed by water blast to SSPC-SP-11.
7.8.6After surfaces have been cleaned, prepped the tank with a mineral wash using PPG T-10 Thinner then spot paint the tanks to a wet film thickness of 8 to 10 mils of Amercoat 133 off-White. Two coats shall be applied. Allow proper cure of coating, 8 to 24 hours between coats.
7.8.7Upon completion of coating repair allow to cure 4 - 7 days before closing tank.
7.8.8Close tank and hyper-chlorinate the tank to a beginning level of 100 ppm free available chlorine (FAC) for a period of 4 hours. At the completion of 4 hours, the FAC must be at least 50 ppm. The water shall be tested hourly for FAC. If at any time the level drops below 50 ppm FAC, the tank shall be dosed with additional chlorine to maintain the 50 ppm FAC level. If the level of chlorine drops below 50 ppm during the test the tank must then be re-dosed and the four hour period started again.
7.8.9Upon completion of sanitizing, the tank shall be flushed to provide water within an acceptable standard.
7.9Marking: None additional
7.10Manufacturer’s Representative: None additional
8.0 GENERAL REQUIREMENTS:
8.1The Contractor shall provide all labor, materials and tools to accomplish this specification item.
8.2 The Contractor shall remove and reinstall interferences necessary to accomplish this specification item.
8.3 Inspection and acceptance of all work shall be by the designated USMMI representative.
VR16-0071
0112-1