Clear the Bridge! by Richard O'Kane Read Free Book Online

quickly. I picked up my Night Order Book from the holder just inside my cabin door. Fraz had thoughtfully inserted a slip of paper with essential figures I might need. I wrote briefly.
    Under way on course 225° true, en route Submarine Base, Pearl
Harbor. Three main engines are on the line, speed 17 knots
.
    There should be no shipping sighted, but do not let this in any way relax your vigilance. I expect the entire watch to be as intent and serious as if we were in a patrol area
.
    Report any changes in weather or other circumstances
.
    If in doubt, call me to the bridge. If in doubt about being in doubt, call me immediately or dive
.
    Remember, no officer will ever be reprimanded for diving, even though it prove unnecessary
.
    In the control room and along the forward and after passageways, the nighttime red lights to hasten our eyes’ adaptation to night vision seemed to impose a general quiet throughout the living spaces, though no such instruction was given. Men going on watch moved quietly, speaking softly. I put my ear close to the pressure hull; the seas beyond the void ballast tanks were just audible. This was as near as one could come to a peaceful moment in a wartime submarine.
    During the midwatch, the OOD reported the wind backing to starboard, and later, the stars breaking through overhead. We were pulling clear of the stormy low pressure area, also confirmed by a rising barometer. If a star fix showed us to be in the leading half of our moving rectangle, as we expected, we could delay our advance while conducting a simulated submerged approach and firing.
    The navigator and Chief Quartermaster Jones were already taking sights when I started for the bridge. I let them come below to work out their position lines before I went on up. A half hour later Fraz’s voice came up the hatch. “It looks good, Captain.” I dropped to the conning tower to see the chart. Things looked good indeed, for we were 15 miles ahead of the midpoint of the rectangle and could now spend an hour or more submerged. If we dived during the forenoon watch, another section would take her down; then we could go to battle stations.
    At first thought, a simulated approach and attack might seem too nebulous to have real training value. However, the same section of the TDC used to determine enemy course and speed could also generate a complete, realistic problem. To have all the elements for a sonar approach required only the recording of the enemy ship’s speed as well as its range and bearing for each minute of the exercise. To introduce the sound bearings realistically, we developed our own device, consisting of my shaving brush and a dynamic microphone. The microphone was plugged into the receptacle in the forward torpedo room that normally received the output from one of our sound heads so that the noises created with our device could be heard on the conning tower receivers.
    Two men, armed with the recorded problem, a stopwatch, and
Tang’s
“super sound device,” conducted the enemy’s maneuvers. An experienced soundman, wearing an earphone so that he could hear what he was doing, could generate any type of propeller noise by repeatedly pushing the bristles of the brush against the microphone—the
thump-thump-thump
of a freighter or, with a faster circular motion, the
swish-swish-swish
of a destroyer. Further, he could control the volume by the pressure he applied and so indicate the range, and could make the sounds in the cadence of a propeller’s revolutions per minute to give an indication of speed.
    The operator’s assistant, with the problem data and the stopwatch, would indicate the correct bearing for each minute on the azimuth scale atop the sound head’s housing. In the conning tower, the sonarman would train the sound head in searching; when he came close to the correct bearing he would be given faint screw noises, which would peak as he crossed the bearing. With a series of these bearings, the propeller revolutions