Back in my time on SSBN’s (1965-1972), my
boat refit in Rota,
Spain and patrolled in the
Med.
We navigated underwater by Ships Inertial
Navigation System (SINS). This was a ship contained system that worked without external signals. The gyros did have to be reset periodically and we did this in several ways.
We trailed a wire
antenna on the surface to receive
LORAN C signals and compared that position with SINS to calibrate it. Trouble with this was that we would often break the wire at
depth or if aggressively maneuvering which required deploying spare wires. Also it wasn’t always as stealthy as we hoped when a flock of birds would decide to hitch a ride on the wire while we were moving.
We also had a TRANSAT System where we would come up to periscope
depth at night and track a
single satellite for about eight minutes and then generate a pretty accurate fix also used to calibrate SINS.
In addition, we had a bottom contour system but seldom used it as it was pretty unreliable.
Lastly we had a Type 11 periscope with a built in
sextant controlled by computer that required a trip to periscope depth. This wasn't so much a position device as a check on SINS heading. Back then the accuracy of a ballistic missile depended on it knowing where it was starting from and leaving there on an accurate heading. Each missile also had its own on board SINS.
Given that we didn’t even have such a thing as an electronic calculator, I imagine today that systems have progressed way beyond what was available then so I wonder what problem needs to be
solved?
There has to be more to this article because any system that required a submarine to transmit would be a non starter. Even passive, the signals would have to be loud enough to be heard but not so loud as to overpower the sounds that the
boat is actually listening for.
Linear Mode
Recent Discussions