DIN ISO 22090-2
Ships and marine technology - Transmitting heading devices (THDs) - Part 2: Geomagnetic principles (ISO 22090-2:2014)
|Publication Date:||1 November 2015|
|ICS Code (Navigation and control equipment):||47.020.70|
This part of ISO 22090 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 shall 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 shall operate
a) at maximum rate of turn 20 °/s and
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.
However, ships within a speed range of 30 kn to 70 kn 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.
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 part of ISO 22090 refer to different technologies. The requirements of this part of ISO 22090 only apply to gyroscopic technology. Other technologies are covered in other parts of ISO 22090.
NOTE 2 All requirements that are extracted from the recommendations of IMO Resolution MSC. 116(73) on performance standards for transmitting heading devices are printed in italics.
A standard magnetic compass with a pickup sensor could be applied as a sensing part of this standard of geomagnetic principle. However the IMO performance resolution MSC.116(73) requires that the THD is intended to be met for the dynamic requirements of the HSC code. Nevertheless, when the THD would be only used other than the HSC, the limit of rate of turn may be 6 °/s instead of 20 °/s.