When the card is given an initial deflection in the following table values, first on one side of the meridian and then on the other, it shall return to within the following table values of its original position.

　

　

The test shall be carried out by deflecting the card 2°, keeping it in this position for at least 10 s and releasing it. The test shall be repeated by deflecting the card on the other side of the meridian. The larger of the two values obtained shall be taken as the error due to friction.

　

The reading may be carried out at the lubber mark or more accurately by means of the compass test stand telescope.

　

　

With the compass rotating at a uniform rotational frequency of 6°/s the horizontal plane, the card deflection when the bowl has been rotated 180° shall not exceed (108/H)°from the magnetic meridian.

　

Alternatively, when rotating at a uniform rotational frequency of 1,5°/s, the card deflection, measured after the bowl has been rotated 380°, shall at no point exceed the following values in the following table.

　

　

The observation shall start after the compass has been rotated 360°. After having given the compass liquid a suitable time to settle, the measurement shall be repeated by rotating the compass in the opposite direction. The average of the values obtained shall be taken to be the swirl error of the compass.

　

　

a) friction of the pivot;

b) magnetic material contained in the compass.

　

In order to determine the cause, a friction test may be carried out on the heading(s) where the irregularity occurs. If the result of this test is satisfactory, a test for magnetic material may then be carried out by obtaining a deviation curve. This will indicate whether there is any magnetic material in the compass.

　

Damp heat test, vibration test and rain and spray test shall be carried out by the methods of testing and required test results of IEC 60945, and shall meet the requirements.

　

　

Type-testing shall be carried out before the binnacle comes into regular service. Each binnacle shall be provided with its compass, azimuth reading device, correctors and, if fitted, a transmitting system.

Individual testing of binnacles and correcting devices is not required.

New devices only are accepted for type-testing.

　

　

Type-testing should be carried out on all binnacles and correcting devices. These include binnacles for projector, reflector or transmitting compasses.

　

There are two types of binnacle to be tested.

　

Where the requirements and test methods are different for these two types, the test methods are specified separately for A1 and A2.

　

It is permissible to supply the A2 binnacle without quadrantal correctors and without Flinders's bar, but when there is provision for fitting these correctors, both shall be provided when the binnacle is submitted for type approval.

　

　

The manufacturer shall produce a written statement for binnacles covering those requirements that cannot be ascertained during the type-test. This statement shall contain the following points:

　

a) the vertical distance between the mid-plane of the directional system magnets and the gimbal bearings centre of the compass supplied;

b) that with the exception of the correcting devices (and where appropriate, certain parts of the compass transmission system), the binnacles and fittings are free from material;

c) when natural wood is used for the exterior of the binnacle it is seasoned tropical hardwood (for example, teak). Any other wood used in the binnacle is to be seasoned hardwood, or marine ply. When a material other than wood is used, its properties are to be stated;

d) all materials used are of sufficient strength;

e) the coercivity of the corrector magnets; (ISO 613,5.2)

f) that the material used for correcting induced fields has a high permeability, a low coercivity and a negligible remanence; (ISO 6I 3,5.2)

g) where wooden parts are joined by an adhesive only, the type of adhesive used.

　

　

Depending on the type of ship on which it shall be fixed, one of two types of binnacle may be used: type A1 or type A2.

　

　

In binnacles type A1, the directional system magnets shall be at least 1 m from the underside of the binnacle deck fillings.

　

(ISO 449, 6.1.1.1) Only high quality non-magnetic materials of sufficient strength shall be used for the construction of binnacles, brackets and holding-down bolts.

　

As the manufacturers have given a guarantee declaration, only sample checks are necessary.

　

　

The axis shall be in the binnacle fore and aft line within 0,5°.

　

The compass verge ring shall remain horizontal to within 2°when the binnacle is tilted 40°any direction.

　

Where there is no or negligible lateral play in the suspension, this can be tested by tilting the compass bowl, while the binnacle remains horizontal and measuring the angle with a clinometer.

　

Should the compass be mounted in a flexible suspension or controlled by springs, then it is necessary to tilt the binnacle and for the compass to remain horizontal. This measurement should be taken both with and without the azimuth reading device or other attachment (for example magnifier or fluxgate) in position.

　

The compass shall be secured against dislodging in any conditions of sea or weather. This securing shall not impair the compass in the free movement within the limits of 4.3.2.3.2.

　

When the compass bowl is inclined 5°in any direction and released, it shall return to within 2°of the horizontal plane.

　

This measurement should be undertaken with a suitable level and with azimuth reading device and any other fittings which may sometimes be attached in position and also without them.

　

The outer gimbal axis shall not be able to move within its bearing more than 0.5 mm in a fore and aft direction.

　

The measurements may be carried out by means of a feeler gauge.

　

　

The horizontal movement of the bowl and gimbaling shall not exceed 5 mm in any direction from the normal position.

　

This measurement may be carried out by means of a gauge or scale, using the binnacle inner rim for reference.

　

The vertical displacement of the compass bowl centre caused by the mass of an azimuth reading device shall not exceed 3 mm.

　

The measurement may be carried out by means of a gauge or scale, using a suitable horizontal plane for reference.

　

　

4.3.2.4.1 Fore and aft marks provided on binnacles shall be in the same vertical plane to within the values in the following table as the axis of the fore-and-aft gimbal bearings.

　

　

The examination may be carried out with the aid of a plumb line and with the compass in the binnacle.

　

4.3.2.4.2 In type A l binnacles, provisions shall be made for any misalignment in respect of the fore and aft line of the ship by turning the binnacle through an angle of not less than 4°and not more than 6°.

　

This requirement is not obligatory in type A2 binnacles, The examination may be carried out with the compass in the binnacle.

　

4.3.2.4.3 The course as read from the projected image shall agree with the course read at the main lubber mark to within 0,5°.

　

Corrector magnets shall be marked red at the north seeking end and shall have a coercivity of not less than 11200 A/m.

All fittings carrying correction devices shall be securely joined to the binnacle and well protected against sea and weather.

　

Suitable devices (for instance a scale) to indicate the position of the correcting devices at any given time shall be provided. Holes or grooves used for horizontal corrector magnets shall be numbered and the numbers shall read from the bottom upwards.

　

Provisions shall be made to secure the correcting devices of the binnacles against unauthorized access and unintentional displacement.

　

The examination shall be carried out visually.

　

Heeling magnets shall be able to produce a vertical flux density over the range - 75 μT to + 75 μT at the directional system magnets.

　

This can be checked by using a vertical force instrument or any other magnetometer or by measuring the magnetic moment and calculating the field intensity.

　

The tube provided for one or more heeling error magnets to correct the influence of vertical magnetism shall be fitted centrally below the compass bowl in the binnacle vertical axis, unless a suitable special device is fitted. When several heeling error magnets are provided for, the casings shall be constructed so that the magnets can be placed in a symmetrical arrangement about its axis. The heeling error magnet, or the holder for the heeling error magnets respectively, shall be capable of being safely secured in position by some suitable means. Provision shall be made so that the distance between the upper end of the correcting magnets and the magnets of the directional system cannot be less than twice the length of the correcting magnets in class A1 binnacles.

　

In type A2 binnacles, no precise dimensions are required, but the effect on the directional system shall not be any less favourable. In particular, provision shall be made so that no correcting system magnets come so close to the directional system as to distort the field and produce a deviation of more than (80/H)°on any course where there is a heel or pitch of 15°.

　

The examination in the case of the type A1 binnacle shall be carried out by inspection.

　

In the case of the type A2 binnacle, which will be smaller, it may be necessary to provide means for changing the vertical field in the vicinity of the directional element. The field thus produced is to be corrected with the heeling magnets, and the binnacle tilted 15°. The resulting deviation shall not exceed (80/H)°.