Staff Biographies

Alvin D. Van Vessem

Alvin D. Van Vessem, an explosives expert, was born February 18, 1918 in Warwick, New York. After graduating from high school, he pursued a degree in mechanical engineering while working for the New York Telegraph Company and later Western Union. When World War II broke out, Van Vessem enlisted in the Army and in 1944 was selected for service in the Manhattan Engineering District's Special Engineer Detachment (SED).

Van Vessem played a large part in the famous 100-ton test of May, 1945. On May 7, he and several colleagues stacked 100 tons of TNT on a wooden platform sitting more than 25 feet above the desert floor. In order to trace the potential fallout pattern of an atomic blast, the TNT was threaded with tubes containing reactor-produced fission products. That afternoon, the TNT was detonated-the largest measured explosion ever conducted.

Shortly after the 100-Ton Test, Van Vessem returned to Los Alamos to help fabricate the first implosion bomb's core. On July 12, he escorted the completed core to the Trinity Site where he helped assemble the test device. It was successfully tested on the 16th, opening up the atomic age.

After the end of World War II, Van Vessem remained at Los Alamos as a member of X-7, the Detonator Development Group. In the spring of 1946 he joined B Division, which was charged with organizing the Navy's first nuclear test series: OPERATION CROSSROADS. The first shot, codenamed "Able," was detonated at an altitude of 520 feet on July 1st. On the 25th a second shot, "Baker," was set off 90 feet underwater. The bombs themselves proved reliable, although the test results were somewhat disappointing.

In November 1946, Van Vessem took a leave of absence from the laboratory in order to complete his degree in mechanical engineering. In early 1947 he received his BS and promptly returned to Los Alamos, rejoining X-7. In 1954 he was promoted to alternate group leader, a position he held until his retirement in 1981. Van Vessem passed away on July 9, 2003.