West is Best and East is Wrong
West is Best and East is Wrong
This will be difficult to believe, in this era of microprocessors contained in cheap handheld consumer products. It was just a few years ago, some time after men had landed on the moon, that I was traipsing around the ocean in a ship of the line, in the most technologically advanced Navy in the world. For navigation, we used Loran-A when we were within a couple of hundred miles of shore. Otherwise, we used no electronics at all.
Primary navigation data was obtained using the hand-held sextant to sight celestial bodies. Since one celestial body provided one line of position, we used a minimum of four bodies to get a fix. This could be done only at twilight, when we could see the stars and the horizon at the same time. During the day, we could shoot the sun and get one line of position, but we did not know where on that line we were. We always shot local apparent noon, to get a latitude reading. None of this works if the weather is cloudy. Sometimes we went for several days without a good fix. (Navigational, I mean.)
In between, we ran a dead reckon. This process was automated, by means of a mechanical analog computer. This computer had two real-time inputs: heading from the gyrocompass and speed from the pit (or pitometer) log. Whenever we got a fix, we put the data into the dead reckoning system, and it kept track of us until we had some better information to use. Note that this system did not account for the ocean's known or unknown currents.
This dead reckoning system provided us with two outputs. One was a spot of light that shined upward through our glass-topped chart table. This spot of light moved across the chart table so as to track our movement across the ocean. We put paper on top of the DRT (Dead Reckoning Tracer), and we made a mark with a pencil every ten minutes or so, to keep track of where we thought or hoped we were.
The other output was a set of analog dials which displayed our latitude and longitude, on a gadget called the DRAI, or Dead Reckoning Analyzer Indicator. Along the bottom of this panel there was a set of toggle switches that served no function. There was a home-made metal guard screwed to the case of the equipment, to prevent anyone from moving these switches. The whole assembly had been painted so many times that the existence of these switches had been forgotten a decade or more ago.
(That was a clue.)
One day we transited the English Channel, on our way to Copenhagen. While we were in the Channel, we could see land, so we used our periscope to take bearings on known, charted landmarks, and we could keep track of our position very well. However, after we had entered the North Sea, we turned back to our old forms of navigation, and we found that the DRT and the DRAI were no longer working. The First Class Signalman reported the malfunction, and the Interior Communications Electricians began working on the problem. They pulled out the technical manuals, and they proceeded to work methodically through the equipment. Finally, they had opened and cleaned every part in the machine, verifying that each component worked properly. They reached the point where they could declare that every component worked, but the machine as a whole did not work.
Mind you, this piece of equipment had two synchros for input, one mechanical integrator to convert speed to distance, and two synchros to drive the output dials. The synchros were simple, three-phase A.C. electric motors. The whole machine was gruesomely simple. You could see every part, and see what it was supposed to do. It couldn't fail to work.
Of course, finally someone turned the page from the maintenance section of the book to the operation section. There was a description of the two forgotten switches, and of their function. We chiseled the paint off the guard, and flipped the one switch from West longitude to East longitude. The machine worked again.