ATLAS Buoy Solid Insert Specifications
Statement of Work:
The contractor shall furnish the necessary personnel, material, equipment, services, shipping and facilities (except as otherwise specified), to perform the following statement of work/specifications.
Toroidal ATLAS Buoys:
1. Provide all labor, materials and shipping to PMEL Seattle, WA of 2.3 meter TAO oceanographic buoys as specified below and as indicated on attached drawings: ATLAS_ATLAS Buoy_Solid Insert-X-X.
2. The Buoy shall be fiberglass over foam, oceanographic buoy with type 316 L stainless steel framework and three (3) attachment points on top and bottom of buoy.
3. Upper and lower attachment points shall be made on jigs to ensure 120 degrees alignment, which will allow for interchangeability of existing buoy towers and bridles onto buoys. The jigs and buoy molds shall be furnished to the contractor as Government Furnished Property. The contractor is responsible for shipping jigs and molds from, and returning them back to PMEL.
4. Top and bottom jigs shall be securely bolted to buoy attachment points using 1-inch hardware (x6) in the top, and bottom jigs during all phases of fiberglass and foam fabrication. Bolts shall be tightened to approximately 90 lft-lbs. Jigs shall remain so attached while fiberglass and foam cool to room temperature.
ATLAS Buoy Fiberglass:
1. The fiberglass lay-up shall be layered with a combination of bulk fiberglass, applied by chopper gun, and 24 OZ Roving. Equal bi-directional plus, minus, 45-degree strand material may be substituted for 24 OZ Roving. Resin to glass ratio shall be pproximately 65 to 35.
2. A smooth surface inside mold shall be used to form the fiberglass skin within which the bulk of the fiberglass shall be laid up. This shall be the required technique with the objective of producing buoys of consistent size and shape. Buoys with a surface finish consisting of dips or waves of greater than ¼ inch may be rejected. All transitions must be fully feathered.
3. Proper fiber glassing techniques shall be followed to prevent delamination during the lifetime of the buoy.
ATLAS Buoy Specifications
ATLAS Buoy Construction:
1. The Fiberglass shall have a maxium thickness of 3/8" and a minimum thickness of 5/16 inch (unless specifically specified *See note #3, on DWG: ATLAS_ATLAS Buoy Solid Insert-X-X , ATLAS Buoy sheet , Page 1) using alternate layers of chopped reinforcement, bi-directional and/or 24 OZ woven Roving. The framework is keyed so that it will fit in only one orientation on the jig. This is the required procedure. After the framework is installed, attach the location jigs to the top and bottom pad eyes. Set the proper height of the frames to the inside of the shell. (The critical measurement here is the overall height of the buoy, i.e., 36 inches.) All gaps between the internal bands and the lower fiberglass shell will be filled with thixopuddy. Apply a 3/8-inch alternating layer of mat and roving extending a minimum of 4 inches on each side of the band to secure the frame to the lower shell. Remove the upper alignment jig to install the upper shell for final assembly. Reattach and tighten, (to approximately 90 ft-lbs. ), the alignment jigs top and bottom.
2. An additional 1/8-inch thickness of reinforcement must be applied to the inner and outer seams. Each 1/8 inch thickness band shall be approximately 14 inches wide consisting of chop, two layers of 1-1/2 OZ mat and two layers of unidirectional Roving. This additional thickness must be feathered into the adjacent areas not in excess of 3 inches on top and bottom to provide a smooth transition. All Voids shall be filled with thixopuddy, and/or duraglass, and covered with a gel coat with surface agent then sanded to fair and re-gel coated as required. The entire finished surface of the buoy is to be coated with gel coat with an air inhibited polyester surface. To the top of the buoy, apply an 18-inch wide strip of 40-mesh sand with gel coat to give a nonskid texture.
3. Any voids or gaps that exist between the stainless plates on the outside of the buoy and the fiberglass must be filled with polyester thixopuddy or duraglass. A smooth bead of polyurethane or polysulfide caulk shall be applied to where the stainless and fiberglass meet.
4. Fill the buoy with a single pour of approved foam and re-fiberglass the foam holes and re-apply the nonskid.
5. THE UPPER AND LOWER JIGS SHALL REMAIN SECURLY ATTACHED, USING 12 EA, 1" BOLTS, DURRING THE FOAMING PROCESS AND SHALL REMAIN ATTACHED UNTIL FOAM HAS REACHED AMBIENT TEMPERATURE.
6. From the centerline up, create four equal radial sections with painter’s tape. Two opposing sections shall be colored with three coats of international orange gel coat with surface agent added to the last coat. The orange gel coat shall surround only one of the stainless steel pad eyes. The two remaining sections shall remain white.
All lines shall be straight and even.
ATLAS Buoy Urethane Foam:
Foam Type: Burtin Corporation, BUC 400-2.0. MIL-P-26514 E
TYPE II CLASS 1 and MIL-P-21929B or equal.
· Foam shall have slow reactivity profile with low exotherm.
· Free rise density: 1.8-2.2 PCF (ASTM D-1622)
· Density within buoy: NTE 2.4 PCF
· Closed Cell (min): 90% (ASTM D-1940)
· Compressive strength: 26.0 Psi parallel to rise, min 10 Psi perpendicular to rise at
72 deg. F. (ASTM-D-1621)
· Water absorption: 0.05 pounds per square foot
· Dimensional stability: Max 8.0 % volume change at 158 degrees F. /100% R.H.
(ASTM-2126)
The entire buoy shall be filled with a homogeneous foam mixture with no voids. Foam process equipment shall have the capability to fill each buoy with a single pour, which shall be the required foaming technique.
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