In an effort to calm public fears about weapons testing, Annie was an "open shot" - civilian reporters were permitted to view it from News Nob, 7 miles south of the shot-tower. Annie was a weapon development test, it was an experimental device (code named XR3) that provided additional information to normalize the yield-vs-initiation time curve. Operation Upshot-Knothole was a series of eleven nuclear test shots conducted in 1953 at the Nevada Test Site. The test series was notable as containing the first time an atomic artillery shell was fired (shot Grable), the first two shots (both fizzles) by University of California Radiation Laboratory-Livermore (LLNL), and for testing out some of the thermonuclear components that would be used for the massive thermonuclear series of Operation Castle. Annie was a 300 foot tower shot delivered on March 17, 1953. A bomb tower is a lightly constructed tower, often 100 to 700 feet high, built to hold a nuclear weapon for an above ground nuclear test. The tower holds the bomb for the purpose of the investigation of its destructive effects and for the adjustment of measuring instruments, such as high-speed cameras. Normally, the bomb tower disintegrates completely on detonation due to the enormous heat of the explosion.