Drawings from: http://www.globalsecurity.org/military/library/policy/navy/nrtc/14308_ch9.pdf
Details at: http://www.hnsa.org/doc/sonar/fig11-3.htm
 |
This large metal cabinet topped with glass
is about waist high. Under the clear glass top was a movable circular
device that was attached to worm gears that controlled movement both fore, aft and side to side. This device was the Dead Reckoning Tracer (DRT) and the glass top was normally covered with a piece of parchment tracing paper. The DRT was coupled to the ships gyro and as the ship moved a light was projected upward onto the parchment paper. The moving bug light provided an instantaneously updated DR position. The operator of the DRT merely marked the paper over the bug light each minute and when the dots were connected it provided a graphically representation of the cutters movement. From: http://www.flightsim.com/cgi/kds?$=main/feature/osv.htm |
Go to: CIC Page