envisioned device was one that would not actuate under less than or under less than . Sandia reported the problem in May 1959, stating that if Falcon warheads had the greater priority, an interim environmental sensing device could be developed. The Air Force subsequently accelerated the availability date for the Falcon missile and Sandia design released the warhead without an environmental sensing device in October 1959. However, revisions were issued in December before warhead production began with a suitable environmental sensing device for Falcon use. A single environmental sensing device for both systems was abandoned at this time and development on the XW-54-X1 and XW-54-X2 for Davy Crockett use began. The XW-54-X2 warhead would lack any environmental sensing device for initial deployment, while the XW-54-X1 fitted with a suitable environmental sensing device would replace the XW-54-X2 as the weapon became available. Sandia were against the development of the XW-54-X2 as simply disconnecting the adaptation kit would disable the weapon's safeties. The Department of Defense cancelled the requirement for the XW-54-X2 (now called the Mk 54 Mod 1) in July 1960 after parts manufacturing slippage delayed production of the warhead. This also caused the accelerated schedule for the Falcon application to slip to January 1961. Production of both the Falcon warhead (now called the Mk 54 Mod 0) and the XW-54-X1 for the Davy Crockett (now called the Mk 54 Mod 2) was achieved in April 1961. Both the Mod 0 and Mod 2 weapons were interchangeable by changing the environmental sensing device. The final weapon was in diameter, in length and in weight, and was packaged in a fiberglass housing coated in a conductive lacquer to provide an electrical shield. Special Atomic Demolition Munition Interest in the Special Atomic Demolition Munition (SADM) began in February 1958 when the Army desired a new munition that could be carried by one man. The project was delayed by the needs of the Falcon and Davy Crockett application until November 1959. The proposal noted that the existing atomic demolition munition (ADM), the T-4 Atomic Demolition Munition, was based on the Mark 9 gun-type artillery shell and that transport required four men, each carrying a section of the weapon. It was felt that the XW-54 SADM proposal could produce a weapon of diameter, long and a weight of including carrying case. The weapon would also have a waterproof housing, have a pack for carrying in