BS ISO 17339:2018 pdf download – Ships and marine technology — Life saving and fire protection — Sea anchors for survival craft and rescue boats
Clamp a test specimen centrally so that its longitudinal centre-line passes through the centre point of the front edges of the jaws. Engage any device for recording the maximum force and elongation at maximum force. Put the movable clamp in motion and extend the test specimen to the point of rupture. Record the maximum force in newtons. Perform the test at least on five test specimens.
22.214.171.124 Compliance criteria The average of five samples shall comply with manufacturer’s specification.
5.1.3 Corrosion test for metal attachments Corrosion-resistant metal attachments shall be qualified by corrosion test in accordance with ISO 9227:2012. After the salt spray test, the metal attachments shall be subjected to strength test as described in 5.5 to demonstrate satisfactory operation. Stainless steel having a Pitting Resistance Equivalent Number (PREN) of 22 or higher does not need to be subjected to corrosion testing. 5.2 Temperature cycling test 5.2.1 Any specimen for the deployment test, the towing test and the strength test, as described in 5.3, 5.4 and 5.5, shall be subjected to the following temperature cycling prior to these tests.
5.2.2 The specimen shall be alternately subjected to surrounding temperatures of −30 °C and 65 °C. These alternating cycles need not follow immediately after each other and the following procedure, repeated for a total of 10 cycles, is acceptable: 1) an 8 h exposure at a minimum temperature of 65 °C to be completed in one day; 2) the specimen removed from the warm chamber that same day and left exposed under ordinary room conditions at a temperature of 20 °C ± 3 °C until the next day; 3) an 8 h exposure at a maximum temperature of −30 °C to be completed the next day; 4) the specimen removed from the cold chamber that same day and left exposed under ordinary room conditions at a temperature of 20 °C ± 3 °C until the next day.
5.3 Deployment test A sea anchor, in its packed condition, with its full length of towing line shall be thrown into water and the line shall then be pulled. The sea anchor shall then attain its designed shape immediately or within a distance of not more than 1 m.
5.4 Towing test
5.4.1 A fully deployed sea anchor shall be towed over a distance of at least 1 km at speeds of 2 knot and 3 knot. The sea anchor shall be observed throughout the towing test and shall remain stable, not breaking through the surface of the water. On completion, the sea anchor and attachments shall be examined and shall not show any signs of deterioration or damage.
5.4.2 With a tension tester (e.g. load cell or spring balance) fitted in the tow line, the sea anchor shall again be towed over a distance of at least 1 km and the tensile force in the line shall be recorded at speeds of 2 knot and 3 knot. If there is a current running, the force shall be recorded in each direction and the mean shall be taken. The drag force measured in the tow line shall comply with Table 1.
5.4.3 With a tension tester (e.g. load cell or spring balance) fitted in the tow line, the sea anchor shall be towed at 3 knot for at least 20 s or until a steady drag-force reading is obtained, whichever is longer. The drag force measured in the tow line shall be not less than that specified in Table 1. The power to the boat shall then be cut. After 20 s the power shall be reapplied until the sea anchor is again being towed at 3 knot or until a steady drag-force reading is obtained, whichever is longer. During the second and subsequent test cycles, the drag-force measured in the tow line shall be not less than that specified in Table 1. This procedure shall be repeated until 20 cycles have been completed. At the end of 20 cycles, the sea anchor shall be examined. The sea anchor shall not be tangled in its shroud lines or turned inside out.
5.5 Strength test To demonstrate the strength of the sea anchor and its attachments to the shroud and towing line, the sea anchor shall be uniformly loaded internally with weight as indicated in Table 3. The sea anchor shall then be suspended by at least 2 m of towing line for a period of 6 h. On completion, the sea anchor, shroud lines and all attachments shall be carefully examined and there shall not be any visible signs of any damage.BS ISO 17339 pdf download.