Ships and marine technology-Transmitting Heading Devices (THDs) - Part 1: Gyro-compasses
1 Scope
This International Standard specifies the construction, performance and testing for Gyro-compass as Transmitting Heading Device required by chapter V, SOLAS 1974 (as amended,).
A Transmitting Heading Device (THD) is an electronic device, which provides information about the ship's true heading.
In addition to the general requirements contained in IMO Resolution A.694 (17) to which IEC 60945 is associated and the relevant standard for the sensing part used, the THD equipment shall comply with th e following minimum requirements.
Where the IMO performance standards which apply to the sensing part do not specify a geographical operating area the THD shall operate;
.1 at maximum rate of turn 20°/s; and
.2 from 70｡?atitude south to 70｡?atitude north as minimum.
The THDs complying with the requirements contained in this International Standard can be used for heading information as contained in Chapter V of the SOLAS Convention.
However, the ships within a speed range of 30 knots to 70 knots shall comply with the requirements of IMO Resolution A.821 (19)
In addition such THD shall meet the dynamic requirements contained in the HSC Code, chapter 13 for the carriage of a suitable device providing heading information.
NOTE 1 Several technologies can be used to detect and transmit heading information. It is illogical to standardize the detection of the heading separately from the transmission of the heading. Therefore separate parts of this standard refer to different technologies. The requirements of this part of the standard only apply to gyroscopic technology. Other technologies are covered in other parts of this standard.
NOTE 2 All requirements that are extracted from the recommendations of IMO Resolutions [Resolution 116 (73)] on performance standards for transmitting heading devices are printed in italics.
2 Normative references
The following normative documents contain, provisions which, through reference in this text, constitute provisions of this International Standard. For dated references, subsequent amendments to, or revisions of, any of these publications do not apply. However parties to agreements based on this International Standard are encouraged to investigate the possibility of applying the most recent editions of the normative documents indicated below. For undated references, the latest edition of the normative document referred to applies. Members of ISO and IEC maintain registers of currently valid International Standards.
ISO 694: Positioning of magnetic compasses in ships.
ISO 8728: Ships and marine technology - Marine Gyro-compasses.
ISO 16328: Ships and marine technology - Gyro-compass for high speed craft.
IEC 60945: Marine navigational equipment・General requirements・Methods of testing and required test results.
IEC 61162: Marine navigation and radiocommunication equipment and systems - Digital interfaces.
International Convention on Safety of Life at Sea (SOLAS) 1974 (amended).
IMO Resolution MSC.116 (73): Performance standards for marine transmitting heading devices (THDs).
IMO Resolution A.424 (XI): Performance standards for Gyro-compasses.
IMO Resolution A.694 (17): General requirements for shipborne radio equipment forming part of the global maritime distress and safety system (GMDSS) and for electronic navigational aids.
