posted by Anonymous .
What were the tube computers of 1946-1958 used for?
Code breaking was one use but the use I am familiar with is generation of tables solving spherical triangles for navigation by sextant. Using a companion volume " Nautical Almanac" you looked up where a ray from the sun or moon or star intercepted the surface of earth at the time you measured its "altitude" or angle above the horizon. You then estimated where you were. The computed tables told you what angle you should have measured and the direction of the object (azimuth). If you measured one minute of arc less, you were one nautical mile further away along the azimuth line than you thought. By taking sights on two objects or by shooting the sun at two different times with an estimate of how you moved between sights you could fix your position. I used these as late as 1958 between Boston and Bermuda and Halifax and even later in Europe. Airplane navigators also used the tables.
By the way, if you include analog as well as digital computers, I was using tube varieties as late as 1964 for simulation of ship motions and vibration measurement and analysis.