scope:

This part of ISO 22090 specifies the construction, performance and testing of gyro-compasses as transmitting heading devices required by chapter V, SOLAS 1974 (as amended). A Transmitting heading device (THD) is an electronic device that 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, it is preferable that the THD equipment comply with the following minimum requirements. Where the IMO performance standards which apply to the sensing part do not specify a geographical operating area that the THD operate; a) at maximum rate of turn 20°/s; b) from 70° latitude south to 70° latitude north as minimum. The THDs complying with the requirements contained in this part of ISO 22090 can be used for heading information as contained in chapter V of the SOLAS Convention.