Gyrokompass

Gyrokompass, or gyrocompass, is a non-magnetic navigation instrument that determines true north by using a rapidly spinning rotor and the rotation of the Earth. It provides a stable heading reference for ships, submarines, and other large vessels, remaining unaffected by magnetic fields and ferrous hull structures.

Principle: A high-speed rotor is mounted in gimbals and allowed to precess under the influence of gravity and the Earth’s rotation. Through controlled damping and feedback, the rotor’s axis aligns with the meridian, so the instrument’s azimuth indicates true north. Because it relies on inertial motion and the planet’s rotation rather than magnetic fields, the gyrocompass delivers a heading independent of local magnetic variations and magnetic interference.

History: The gyrocompass was developed in the early 20th century by Hermann Anschütz-Kaempfe in Germany and by Elmer Sperry in the United States, each pursuing analogous concepts. After refinements, practical gyrocompasses entered naval service in the 1910s and 1920s and became standard equipment on most warships and merchant vessels in the ensuing decades.

Modern use: Although modern navigation increasingly integrates ring-laser and fiber-optic gyros and GPS-based systems, the gyrocompass remains a fundamental heading reference in many vessels due to its independence from magnetic fields. It is commonly part of integrated navigation suites and is often used in conjunction with rate gyros and drift calculations, particularly on submarines and ships operating in polar or magnetically disturbed regions.