11.4.1 A vessel should be tested in the fully
loaded conditions (which should correspond to the freeboard assigned)
to ascertain the angle of heel and the position of the waterline which
results when all persons which the vessel is to be certificated to
carry are assembled along one side of the vessel. (The helmsman may
be assumed to be at the helm.) Each person may be substituted by a
mass of 75kg for the purpose of the test.
The vessel will be judged to have an acceptable standard of
stability if the test shows that:-
-
.1 the angle of heel does not exceed 7 degrees;
and
-
.2 in the case of a vessel with a watertight weather
deck extending from stem to stern, as described in Section
4.1.1, the freeboard to deck is not less than 75mm at any point.
-
.3 The angle of heel may exceed 7 degrees, but
should not exceed 10 degrees, if the freeboard in the heeled condition
is in accordance with that required by Section
12 in the upright condition.
11.4.2 Additionally, for vessels over 15 metres
in length, the heeling moment applied during the test described in
11.4.1 should be calculated. Using the formula below, the vessel should
attain a value of initial GM not less than 0.5m if using an estimated
displacement, or 0.35m if the displacement of the vessel is known
and can be verified by the Certifying Authority.
where:
|
HM |
= |
Heeling moment
in kilogramme-metres |
|
θ |
= |
angle of
heel in degrees obtained from the test as defined in 11.4.1 |
|
Δ |
= |
the displacement
of the vessel in kilogrammes, either estimated, or measured and verified
by the Certifying Authority |
11.4.3 For vessels carrying a combination of passengers
and cargo, for which the cargo element does not exceed 1000kg (see
definitions), the test defined in Section 11.4.1 should be carried
out with the full complement of passengers and cargo, and additionally
with passengers only. For the purposes of these tests the cargo may
be assumed to retained at its normal stowage position.
-
11.4.3.1 In all cases, the maximum permissible
weights of persons and/or cargo derived from the tests conducted shall
be recorded on the certificate. Vessel loading will be restricted
by the position freeboard mark and maximum permissible weight, and
thus for the purposes of this test, attention should be paid to any
activity related equipment where this may be significant, e.g. diving
equipment.
11.4.4 It should be demonstrated by test or by
calculation that an open boat, when fully swamped, is capable of supporting
its full outfit of equipment, the total number of persons for which
it is to be certificated and a mass equivalent to its engine and full
tank of fuel.
11.4.5 Vessels complying with ISO 12217 Part 1
'Small craft - Stability and buoyancy assessment and categorisation
- Non-sailing boats of hull length greater than or equal to 6 metres',
assessed using any Option of Section 5.3 -
'Test and calculations to be applied', may as an alternative, after
verification of the stability assessment by the Certifying Authority,
be assigned an area of operation in accordance with Section 11.3.9.