Figure 4-10.-Underwater log system.
switch and is operated by the throttleman. The shaft
rpm is used to determine approximate ships speed.
The underwater log system (fig. 4-10) provides
60-Hz synchro signals scaled at 40 and 100
knots/revolution and 400-Hz signals scaled at 10, 40,
and 100 knots/revolution. A resettable distance counter
is provided on the front of the indicator-transmitter.
Distance output is a 60-Hz synchro signal scaled at 360
revolutions per nautical mile.
In this chapter, we introduced some of the most
common gyrocompass systemsMk 19, Mk 23, Mk 27,
and AN/WSN-2. Additionally, we talked about the
AN/WSN-5 inertial navigation system, electro-
magnetic underwater log system, and the data they
If a failure were to occur in one of these systems and
introduce error to your equipment, you are now better
able to isolate the faulty equipment and restore the
overall system operability.