3 Immersion Suits, Anti-Exposure Suits and Thermal Protective Aids

  3.1.1 These tests should be carried out with at least six able-bodied persons of the following heights and weights:

At least one and not more than two of the persons should be females with not more than one female in the same height range.

  3.1.2 If the immersion suit or anti-exposure suit is to be worn in conjunction with a lifejacket, the lifejacket should be worn over the immersion suit or anti-exposure suit for the tests prescribed in 3.1.3 to 3.1.12 inclusive.

  3.1.3 Following a demonstration, each test subject should be able to unpack, don and secure the immersion suit or anti-exposure suit over their test clothing without assistance in less than 2 min. This time should include the time to don any associated clothing, inflate any orally inflated chambers if fitted, and don a lifejacket, if such is to be worn in conjunction with the immersion suit or anti-exposure suit, and the test subjects should be able to don such lifejacket without assistance.

  3.1.4 The immersion suit or anti-exposure suit should be capable of being donned in 5 min at an ambient temperature as low as -30°C. Before the donning test the packed immersion suit or anti-exposure suit should be kept in a refrigerated chamber at a temperature of -30°C for 24 h.

  3.1.5 When wearing the immersion suit or anti-exposure suit, the test subjects should be able to climb up and down a vertical ladder of at least 5 m in length and demonstrate no restriction in walking, bending over or arm movement. The test subjects should be able to pick up a pencil and write. The diameter of the pencil should be 8 to 10 mm.

  3.1.6 With the heads of the seated test subjects in a fixed position, the lateral fields of vision should be at least 120° when wearing the immersion suit or anti-exposure suit.

  3.1.7 When wearing the immersion suit or anti-exposure suit in conjunction with a lifejacket if required, the test subjects should float face-up with their mouths clear of the water by at least 120 mm and be stable in that position. For a buoyant insulated immersion suit worn without a lifejacket, an auxiliary means of buoyancy such as an orally inflated bladder behind the wearer's head may be used to obtain this freeboard, provided that the freeboard obtained without the auxiliary means of buoyancy is at least 50 mm. The freeboard should be measured from the water surface to the nose and mouth with the test subject at rest. The freeboard of the anti-exposure suit without a lifejacket should be at least 50 mm. The position of the lifejacket light should permit it to be visible over as great a segment of the upper hemisphere as is practicable.

  3.1.8 Except where it has been demonstrated that the immersion suit or anti-exposure suit will right the test subjects within 5 s, the test subjects should each demonstrate that they can turn themselves from a face-down to a face-up position in not more than 5 s.

  3.1.9 Following a jump by each test subject into water from a height sufficient to totally immerse the body, the ingress of water into the immersion suit or anti-exposure suit should not exceed a mass of 500 g. This may be determined from the difference in the combined mass of the test subject and the immersion suit or anti-exposure suit (pre-wetted), as measured prior to the jump and immediately after the jump. Weighings should be performed on a machine accurate to ± 100 g.

  3.1.10 The immersion suit or anti-exposure suit and its attachments should not be damaged or dislodged in any way following a jump from a height of 4.5 m vertically into the water. It should be established by questioning the test subjects that the suit does not injure the wearer as a result of this test.

  3.1.11 The ingress of water into the pre-wetted suit should not exceed a mass of 200 g following:

• .1 a period of flotation in calm water for 1 h; or

• .2 swimming for 20 min for a distance of at least 200 m.

The mass of water ingress should be measured by weighing the test subject and the suit in accordance with the method prescribed in subparagraph 3.1.9.

  3.1.12 All test subjects, each wearing a lifejacket but not the immersion suit or anti-exposure suit should attempt to swim 25 m and board a liferaft or a rigid platform with its surface 300 mm above the water surface. Test subjects who successfully complete this task should also perform it wearing the immersion suit or anti-exposure suit.

  3.1.13 After all its apertures have been sealed, an immersion suit or anti-exposure suit should be immersed under a 100 mm head of diesel oil for 24 h. The surface oil should then be wiped off and the immersion suit or anti-exposure suit subjected to the test prescribed in 3.1.11. The ingress of water should not exceed a mass of 200 g.

  3.1.14 In lieu of the test for oil resistance prescribed in 3.1.13, either of the following tests may be conducted:

• .1 After all apertures have been sealed, the suit should be immersed under a 100 mm head of diesel oil for a period of 24 h at normal room temperature, if necessary using weights to keep the suit submerged. Any surface oil should then be wiped off and the suit turned inside out. The suit should then be laid on a table suitable for collecting and draining off any leakage and be supported at the neck aperture by a suitably designed hanger. The suit should then be filled with water to neck level which should be 300 mm above the table. The suit should be left in this position for 1 h and the leakage collected and weighed. The leakage should not exceed a mass of 200 g.

• .2 Representative samples of the exterior fabric and seams should be immersed under a 100 mm head of diesel oil for 24 h. After removal from the oil, samples should be wiped off before being subjected to a hydrostatic test of a 1 m water head and a tensile seam strength of 150 N.

  3.1.15 An immersion suit or anti-exposure suit should be subjected to the fire test as prescribed in paragraph 1.5. If necessary, the immersion suit or anti-exposure suit should be draped over a hanger to ensure the whole immersion suit or anti-exposure suit is enveloped in the flames. The immersion suit or anti-exposure suit should not sustain burning for more than 6 s or continue melting after being removed from the flames.

  3.1.16 An immersion suit or anti-exposure suit should be subjected to the temperature cycling as prescribed in 1.2.1 and should show no sign of damage such as shrinking, cracking, swelling, dissolution or change of mechanical qualities.

  3.1.17 A buoyancy test, as prescribed in 2.2, should be carried out to establish that the buoyancy of an immersion suit or anti-exposure suit designed to be worn without a lifejacket is not reduced by more than 5% after 24 h submersion in fresh water.

  3.1.18 The immersion suit or anti-exposure suit should be subjected to the body strength tests prescribed in 2.5.1, except the load applied should be 1350 N to the parts other than the lifting loop. For the lifting loop strength test, a force of not less than 3200 N should be applied. The immersion suit or anti-exposure suit may be cut if necessary to accommodate the test device.

  3.2.1 These tests should be performed as described below. The thermal protective qualities may be measured using a thermal manikin, when such a method is required by an Administration and has been demonstrated to provide test results which correlate satisfactorily in all aspects to test results using human subjects.

  3.2.2 If the test should be performed by human subjects, they should be medically examined before being accepted for participation in the tests. Each design of immersion suit or anti-exposure suit is to be tested by the test subjects specified in subparagraph 3.1.1.

  3.2.3 Where human subjects are used, the tests should always be conducted under the supervision of a physician. Emergency resuscitation equipment should be available during all tests. For safety reasons, ECG should be monitored during every test. Testing should be stopped at the wish of the test subjects, if the falling rate of the core temperature is more than 1.5°C per hour after the first half hour, if the skin temperature of the hand, foot or lumbar region should fall below 10°C, or if the attending physician considers it advisable.

  3.2.4 When testing with human subjects, continuous body core temperature (rectal temperature) and skin temperatures of lumbar region, both hands, calves, feet (foot instep) and heels, should be measured. The accuracy of the measuring system should be ±0.2°C. Appropriate corresponding measurements should be taken if a manikin is used in lieu of human subjects.

  3.2.5 Prior to the tests, the same amount of water resulting from the jump test in paragraph 3.1.9 should be poured into the dry immersion suit or anti-exposure suit worn over the dry test clothing specified in 3.2.6 by the test subject lying down.

  3.2.6 The test subjects should wear a standard range of clothing consisting of:

• .1 underwear (short sleeved, short legged);

• .2 shirt (long sleeved);

• .3 trousers (not woollen); and

• .4 woollen socks.

  3.2.7 If the immersion suit or anti-exposure suit is to be worn in conjunction with a lifejacket, the lifejacket should be worn during the thermal protective tests.

  3.2.8 In addition to the clothing specified in paragraphs 3.2.6 and 3.2.7, the test subject should wear two woollen pullovers.

  3.2.9 Each test subject should wear an immersion suit previously subjected to the jump test in paragraph 3.1.10. Following a 1 h period of immersion, with the hands gloved, in circulating calm water at +5°C, each test subject's body core temperature should not fall more than 2°C below the normal level of the subject's temperature.

  3.2.10 Immediately on leaving the water after completion of the test prescribed in 3.2.9 the test subject should be able to pick up a pencil as specified in paragraph 3.1.5 and write.

  3.2.11 Each test subject should wear an immersion suit previously subjected to the jump test in paragraph 3.1.10. Following a 6 h period of immersion, with the hands gloved, in circulating calm water at between 0° and +2 °C, each test subject's body core temperature should not fall more than 2°C below the normal level of the test subject's temperature.

  3.2.12 The immersion suit should provide sufficient thermal protection to ensure that immediately on leaving the water after a 1 h period of immersion, with hands gloved, in circulating calm water at +5°C, each test subject can pick up a pencil as specified in paragraph 3.1.5 and write. Alternatively, at the manufacturer's option, the ability to pick up a pencil as specified in paragraph 3.1.5 and write may be demonstrated immediately on leaving the water after completion of the test prescribed in 3.2.11.

  3.2.13 Each test subject should wear an anti-exposure suit previously subjected to the jump test in paragraph 3.1.10. Following a 1 h period of immersion, with the hands gloved and hood donned, in circulating calm water at a temperature of + 5°C, each test subject's body core temperature should not fall more than 2°C below the normal level of the test subject's temperature.

  3.2.14 Immediately on leaving the water after completion of the test prescribed in paragraph 3.2.13, the test subject should be able to pick up a pencil as specified in paragraph 3.1.5 and write.

  3.3.1 It should be demonstrated that the fabric from which the thermal protective aid is constructed can maintain its watertight integrity when supporting a column of water 2 m high.

  3.3.2 It should be demonstrated by test that the fabric has a thermal conductance of not more than 7,800 W/(m² K).

  3.3.3 A thermal protective aid should be subjected to temperature cycling as prescribed in 1.2.1 and should show no sign of damage such as shrinking, cracking, swelling, dissolution or change of mechanical qualities.

  3.3.4 For these tests a group of at least six test subjects of different ages, both male and female in the large, medium and small size range should be selected.

  3.3.5 The test clothing worn by the test subjects should be as prescribed in 3.2.6 and 3.2.8.

  3.3.6 Following a demonstration, the test subjects should be able to unpack and don the thermal protective aid over a lifejacket when seated in a survival craft.

  3.3.7 The thermal protective aid should be capable of being unpacked and donned at an ambient temperature of -30°C. Before the donning test the thermal protective aid should be kept in a refrigerated chamber at a temperature of -30°C for 24 h.

  3.3.8 If the thermal protective aid impairs the ability of the test subjects to swim, it should be demonstrated that it can be discarded by the test subjects, when immersed in water, in not more than 2 min.

  3.3.9 After all its apertures have been sealed, a thermal protective aid should be immersed under a 100 mm head of diesel oil for 24 h. The surface oil should then be wiped off and it should be established that the thermal conductance is not more than 7,800 W/(m²·K).