46 CFR § 160.047-4 - Construction.
(a) General. This specification covers buoyant vests which essentially consist of a vest-cut envelope containing compartments in which are enclosed pads of buoyant material arranged and distributed so as to provide the proper flotation characteristics and buoyancy required to hold the wearer in an upright backward position with head and face out of water. The buoyant vests are also fitted with tapes, webbing, and hardware to provide for proper adjustment and close and comfortable fit to the bodies of various size wearers.
(b) Envelope. The envelope or cover shall be cut to the pattern shown on Dwg. No. 160.047–1, Sheet 1, for adult size, and Sheets 2 and 3 for child sizes, and sewed with seams and stitching as shown on the drawing. Three compartments shall be formed to hold the buoyant pad inserts, two front compartments and one back compartment, and reinforcing strips of the same material as the cover shall be stitched to the inside of the front compartments in way of the strap attachments as shown by the drawings. As alternate construction, the front and/or back cover panels may be made in two pieces, provided that the two pieces are joined by a double stitched seam from the top center of the neck hole to the top of the vest as shown in Section J-J of the drawings.
(c) Pad inserts—(1) Forming and sealing. The buoyant pad inserts shall each be formed from two pieces of film cut to the patterns shown by Dwg. No. 160.047–1, Sheet 4, which shall be heat-sealed tight. The heat-sealed pad seams shall show an adhesion of not less than 8 pounds when 1 inch strips cut across and perpendicular to the seams are pulled apart at a rate of separation of the clamping jaws of the test machine of 12 inches per minute.
(2) Kapok-filled pads for Models AK–1, CKM–1, and CKS–1. The buoyant pad inserts for Models AK–1, CKM–1, and CKS–1 buoyant vests shall be filled with kapok distributed as provided in Table 160.047–4(c)(2).
Table 160.047–4(c)(2)—Distribution of Kapok in Buoyant Pad Inserts
| Model AK–1 (minimum) | Model CKM–1 (minimum) | Model CKS–1 (minimum) | |
|---|---|---|---|
|
|
|
|
|
| Front pad (2) (each) | 5.75 | 3.75 | 2.50 |
| Back pad | 4.00 | 2.50 | 2.00 |
| Total | 15.50 | 10.00 | 7.00 |
(3) Fibrous glass-filled pads for Models AF–1, CFM–1, and CFS–1. The buoyant pad inserts for Models AF–1, CFM–1, and CFS–1 buoyant vests shall be filled with fibrous glass distributed as provided in Table 160.047–4(c)(3).
Table 160.047–4(c)(3)—Distribution of Fibrous Glass in Buoyant Pad Inserts
| Model AF–1 (minimum) | Model CFM–1 (minimum) | Model CFS–1 (minimum) | |
|---|---|---|---|
|
|
|
|
|
| Front pad (2) (each) | 10.25 | 6.75 | 4.50 |
| Back | 7.25 | 4.50 | 3.50 |
| Total | 27.75 | 18.00 | 12.50 |
(4) Displacement of buoyant pad inserts. The volume of the finished individual heat-sealed buoyant pad inserts shall be such as to provide buoyancy as set forth in Table 160.047–4(c)(4) when tested in accordance with the method set forth in § 160.047–5(e)(1), except that the pad covers shall not be slit open and the period of submergence shall be only long enough to determine the displacement of the pads.
Table 160.047–4(c)(4)—Volume Displacement of Sealed Pads
| Models AK–1 and AF–1 | Models CKM–1 and CFM–1 | Models CKS–1 and CFS–1 | |
|---|---|---|---|
| Each | Each | Each | |
| Front pads | 6
|
4
|
2
|
| Back pads | 4
|
3
|
2
|
(d) Tie tapes. The tie tapes at the neck shall finish not less than 12 inches in length for both adult and child size buoyant vests. They shall be arranged and attached to the envelope as shown by the drawings, and the free ends shall be doubled over and stitched in accordance with section H-H.
(e) Body strap, hardware, and reinforcing tape. The body strap, hardware, and reinforcing tape shall be arranged as shown on the drawings and attached to the envelope with the seams and stitching indicated.
(f) Stitching. All stitching shall be a short lock stitch conforming to Stitch Type 301 of Federal Standard No. 751, and there shall be not less than 7 nor more than 9 stitches to the inch. Both ends of the stitching forming the shoulder hinge seams and the top and bottom closing seams of the envelope shall be backstitched approximately 1/2 inch.
(g) Workmanship. Buoyant vests shall be of first-class workmanship and shall be free from any defects materially affecting their appearance or serviceability.