scope:

NEN-ISO 22090-1 specifies the construction, performance and testing of gyro-compasses as transmitting heading device 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, the THD equipment should comply with the following minimum requirements. Where the IMO performance standards that apply to the sensing part do not specify a geographical operating area that the THD should operate; a) at maximum rate of turn 20 °/s; b) from 70º latitude south to 70º 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. However, ships within a speed range of 30 knots to 70 knots should comply with the requirements of IMO Resolution A.821 (19) In addition, such THD should meet the dynamic requirements contained in the HSC Code, chapter 13 for the carriage of a suitable device providing heading information.