Design of the Sperry Mk XIV Gyro-Compass

The Sperry Mk XIV was a very popular Gyro-Compass of the WWII era, used on thousands of ships. It's proper operation was a matter of life-or-death in this mission critical role.

This old training video explains the key design elements required to build a gyroscope capable of sensing and responding to the rotation of the Earth and using that feedback to align the compass to the North/South rotational axis of the Earth by non-magnetic means.

The most critical elements are a sufficiently massive gyroscope mounted in an extremely low-friction way so it can detect and respond to the very minute precessive forces generated by the rotation of the Earth. In this design this is accomplished by having the 55 pound gyroscope spinning at 6000 RPM (called the Sensitive Element) mounted by a small wire which is then suspended on a Phantom Element which uses a sensor to detect the slightest rotation of the Sensitive Element and then rotates the wire to keep the torsional forces on the wire near zero.

Quote: "Although the gyrocompass has 150 times the directive force of the magnetic compass, as it turns towards the meridian, it still would not be sufficient to overcome the friction of an ordinary support. Since even the finest ball bearings would offer too much resistance a practically frictionless method of mounting is employed. To accomplish this a phantom ring is provided to form the basic part of the second major assembly, the phantom element."

Today we have small digital gyroscopes in our phones and game controllers but they are noisy and not sensitive enough to sense the Earth's rotation by themselves yet.

Gyro-Compass in operation (a Russian model):    • Видео  

Thanks to ‪@Yishai4Truth for the video.‬

Manual https://www.maritime.org/doc/gyromk14...