M117 General Purpose Bomb
The M117 is a free-fall, unguided, general purpose [GP] 750-pound bomb. Its usual fuzes are the mechanical M904 (nose) and M905 (tail), or the mechanical FMU-54 (tail). The M117 is employed in several configurations.
The basic M117 dates from the Korean War and uses a low-drag tail fin for medium and high-altitude deliveries.
The M117R (Retarded) uses a special fin assembly providing either high-drag or low-drag release options. For low altitude deliveries, the tail assembly opens four large drag plates which rapidly slow the bomb and allow the aircraft to escape its blast.
The M117D (Destructor) is similar to the M117R but uses a magnetic influence fuze which enables the bomb to function as a mine. The M117D is released in a high-drag configuration for ground implant or shallow water mining. It detonates when an object passing near the bomb triggers the fuze.
The M117 series was used extensively during the Vietnam War, and B-52G aircraft dropped thousands of tons of M117 and M117R bombs during Operation Desert Storm. The B-52s dropped virtually all of the M117 bombs during Desert Storm.
With the receipt of a contract in 1995 to perform demilitarization on 750-pound Tritonal filled bombs, Crane Army Ammunition Activity designed and developed a process that allows the explosive material to be removed through the nose of the bomb skin, eliminating the need for a separate facility to remove the base of the bomb.
The traditional approach to the demilitarization of a 750-pound Tritonal-filled bomb at Crane Army Ammunition Activity (CAAA) or any other government facility was open detonation or manual extraction by cutting off the base of the bomb and steam- or autoclave-out the explosive material. There were several drawbacks to both methods. With open detonation, neither the explosive nor the metallic container could be recovered, the emissions required extensive tracking and reporting to the proper authorities, and weather conditions determined the work schedule. The second method required the base of the bomb to be removed with a power metal bomb saw. The operator would have to set up the operation at one facility and then move to a remote facility to view the actual cutting process by video transmission. The resultant residue in the water from this cutting procedure also required purification.
CAAA did not have the facility for the treatment of the water nor a bomb saw. It is estimated that such a facility would cost $500,000. With the receipt of a contract in 1995 to perform demilitarization on 750-pound Tritonal filled bombs, CAAA designed and developed a conduit cutting tool that is inserted into the nose cavity liner and manually cuts the swaged tubing. This approach is done by removing the nose fuze wall liner, and using a high-pressure waterjet nozzle to remove the tar nose pad. The bomb is then placed nose first into an autoclave explosive collection system to melt out the Tritonal explosive material under controlled heat and pressure procedures. The explosive is then pumped to a holding vacuum to bring the moisture content down to an acceptable level where it is transported to a conveyor belt for additional cooling prior to packaging for shipment. This extraction method allows the explosive and the metal bomb skin to be recycled commercially, with the option of retaining small donor quantities of Tritonal explosives for use in other open detonation applications at CAAA. Secondly, the handling of the explosive articles is reduced by 50%, and has shown a four to six times faster turnaround in the meltout operation over steam wand applications.
Since the introduction of the Autoclave Bomb Meltout System in 1996, more than nine million pounds of Tritonal explosive and 8.75 million pounds of steel have been recovered from 24,497 bombs. This process has also been adopted by other facilities within the Army commands that perform demilitarization.
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