Mark 21 nuclear bomb
The Mark 21 nuclear bomb was a United States nuclear gravity bomb first produced in 1955. It was based on the TX-21 "Shrimp" prototype that had been detonated during the Castle Bravo test in March 1954. While most of the Operation Castle tests were intended to evaluate weapons intended for immediate stockpile, or which were already available for use as part of the Emergency Capability Program, Castle Bravo was intended to test a design which would drastically reduce the size and costs of the first generation of air-droppable atomic weapons (the Mk 14, Mk 17 & Mk 24). At long, in diameter, and weighing , the Mk-21 was half the length and one-third the weight of the Mk-17/24 weapons it replaced. Its minimum yield was specified at four megatons.
Castle Grande
McDougal then loaned his old friend and political mentor, Senator William Fulbright, $700,000 to buy out the bulk of Ward's remaining holdings. The net effect was to remove Ward's non-recourse loan from the Madison books and generate substantial sales profits and commissions for Madison. The transactions were designed to be confusing to keep the regulators from finding Ward's loan and Madison's full investment in Castle Grande. The federal thrift examiners arrived the first week of March, 1986. The Dean Paul loan done on February 28.